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Cystic epithelia acquire mesenchymal-like features in polycystic kidney disease (PKD). In this phenotypic alteration, it is well known that transforming growth factor (TGF)-β/Smad3 signaling is involved; however, there is emerging new data on Smad3 phosphoisoforms: Smad3 phosphorylated at linker regions (pSmad3L), COOH-terminal regions (pSmad3C), and both (pSmad3L/C). pSmad3L/C has a pathological role in colorectal cancer. Mesenchymal phenotype-specific cell responses in the TGF-β/Smad3 pathway are implicated in carcinomas. In this study, we confirmed mesenchymal features and examined Smad3 phosphoisoforms in the cpk mouse, a model of autosomal recessive PKD. Kidney sections were stained with antibodies against mesenchymal markers and domain-specific phospho-Smad3. TGF-β, pSmad3L, pSmad3C, JNK, cyclin-dependent kinase (CDK) 4, and c-Myc were evaluated by Western blotting. Cophosphorylation of pSmad3L/C was assessed by immunoprecipitation. α-Smooth muscle actin, which indicates mesenchymal features, was expressed higher in cpk mice. pSmad3L expression was increased in cpk mice and was predominantly localized in the nuclei of tubular epithelial cells in cysts; however, pSmad3C was equally expressed in both cpk and control mice. Levels of pSmad3L, JNK, CDK4, and c-Myc protein in nuclei were significantly higher in cpk mice than in controls. Immunoprecipitation showed that Smad3 was cophosphorylated (pSmad3L/C) in cpk mice. Smad3 knockout/ cpk double-mutant mice revealed amelioration of cpk abnormalities. These findings suggest that upregulating c-Myc through the JNK/CDK4-dependent pSmad3L pathway may be key to the pathophysiology in cpk mice. In conclusion, a qualitative rather than a quantitative abnormality of the TGF-β/Smad3 pathway is involved in PKD and may be a target for disease-specific intervention.

Beppu H, Takayanagi N, Tomita Y, Mizutani K, Orand A, Tamai I, Takahashi H, Sonoda S. Improvement of gait and coordinated movement by forced gait training in cerebellar ataxic B6-wob/t mice. Jpn J Compr Rehabil Sci 2015; 6: 64-70. Objective: The effect of forced gait training was investigated in cerebellar ataxic mice (B6-wob/t) using gait analysis and a rota-rod test. Methods: B6 and B6-wob/t mice were divided into non-exercise (NEx) and exercise (Ex) groups. The Ex group received forced gait training with a running wheel at 2 m/min for 50 minutes, three times a day, six days a week, for 12 weeks. The rota-rod test was performed every 4 weeks during this period, and gait was evaluated using our pelvic axis-based gait analysis method (pelvic axis method) when a significant difference was noted between the NEx and Ex groups. The multiple comparison test was used for statistical analysis. Results: After gait training for 12 weeks, the time until falling in the rota-rod test was significantly extended to 115 seconds in the Ex group compared to that (90 seconds) in the NEx group, and the hindlimb step width measured using the pelvic axis method was significantly narrower in the EX than NEx group. Conclusion: Forced gait training may be effective for ataxic symptoms of B6-wob/t. The combination of the pelvic axis-based gait analysis and rota-rod test was useful to evaluate the improvement of ataxia.

Cystic epithelia acquire mesenchymal-like features in polycystic kidney disease (PKD). In this phenotypic alteration, it is well known that transforming growth factor (TGF)-β/Smad3 signaling is involved; however, there is emerging new data on Smad3 phosphoisoforms: Smad3 phosphorylated at linker regions (pSmad3L), COOH-terminal regions (pSmad3C), and both (pSmad3L/C). pSmad3L/C has a pathological role in colorectal cancer. Mesenchymal phenotype-specific cell responses in the TGF-β/Smad3 pathway are implicated in carcinomas. In this study, we confirmed mesenchymal features and examined Smad3 phosphoisoforms in the

Background: The growth-associated increase in the blood glucose level of animals with Type 2 diabetes is inhibited by moderate hyperbaric exposure at 1.25 atmospheres absolute (ata) with 36% oxygen, presumably due to an increase in oxidative metabolism. However, there are no data available regarding the effect of moderate hyperbaric oxygen (HBO) on diabetes-induced cataracts. Methods: Four-week-old mice with Type 2 diabetes and cataracts were exposed to 1.25 ata with 36% oxygen, 6 h daily, for 12 weeks, followed by normal conditions at 1 ata with 21% oxygen for 16 weeks (cataract + hyperbaric group). Levels of blood glucose and derivatives of reactive oxygen metabolites (dROMs), used as an index of oxidative stress, and the turbidities of the lenses from these mice at 4, 8, 12, 16, and 32 weeks of age were compared with those of control and diabetic (cataract group) mice not exposed to HBO. Results: Non-fasting and fasting blood glucose levels were lower in the cataract + hyperbaric group at 12, 16, and 32 weeks of age than in the age-matched cataract group. The levels of dROMs were lower in the cataract + hyperbaric group at 16 and 32 weeks of age than in the age-matched cataract group. The turbidities of the peripheral and central regions of the lenses were lower in the cataract + hyperbaric group at 12, 16, and 32 weeks of age than in the age-matched cataract group. Conclusions: Hyperbaric exposure at 1.25 ata with 36% oxygen delays cataract development and progression in mice with Type 2 diabetes.

In polycystic kidney disease (PKD), cyst lining cells show polarity abnormalities. Recent studies have demonstrated loss of cell contact in cyst cells, suggesting induction of epithelial-to-mesenchymal transition (EMT). Recently, EMT has been implicated in the pathogenesis of PKD. To explore further evidence of EMT in PKD, we examined age- and segment-specific expression of adhesion molecules and mesenchymal markers in PCK rats, an orthologous model of human autosomal-recessive PKD. Kidneys from 5 male PCK and 5 control rats each at 0 days, 1, 3, 10, and 14 wk, and 4 mo of age were serially sectioned and stained with segment-specific markers and antibodies against E-cadherin, Snail1, β-catenin, and N-cadherin. mRNAs for E-cadherin and Snail1 were quantified by real-time PCR. Vimentin, fibronectin, and α-smooth muscle actin (α-SMA) expressions were assessed as mesenchymal markers. E-cadherin expression pattern was correlated with the disease pathology in that tubule segments showing the highest expression in control had much severer cyst formation in PCK rats. In PCK rats, E-cadherin and β-catenin in cystic tubules was attenuated and localized to lateral areas of cell-cell contact, whereas nuclear expression of Snail1 increased in parallel with cyst enlargement. Some epithelial cells in large cysts derived from these segments, especially in adjacent fibrotic areas, showed positive immunoreactivity for vimentin and fibronectin. In conclusion, these findings suggest that epithelial cells in cysts acquire mesenchymal features in response to cyst enlargement and participate in progressive renal fibrosis. Our study clarified the nephron segment-specific cyst profile related to EMT in PCK rats. EMT may play a key role in polycystic kidney disease.

In polycystic kidney disease, abnormal epithelial cell proliferation is the main factor leading to cyst formation and kidney enlargement. Cyclic AMP (cAMP) is mitogenic in cystic but antimitogenic in normal human kidney cells, which is due to reduced steady-state intracellular calcium levels in cystic compared to the normal cells. Inhibition of intracellular calcium entry with channel blockers, such as verapamil, induced cAMP-dependent cell proliferation in normal renal cells. To determine if calcium channel blockers have a similar effect on cell proliferation in vivo, Cy/+ rats, a model of dominant polycystic kidney disease, were treated with verapamil. Kidney weight and cyst index were elevated in verapamil-treated Cy/+ rats. This was associated with increased cell proliferation and apoptosis, elevated expression, and phosphorylation of B-Raf with stimulation of the mitogen-activated protein kinase MEK/ERK (mitogen-activated protein kinase kinase/extracellular-regulated kinase) pathway. Verapamil had no effect on kidney morphology or B-Raf stimulation in wild-type rats. We conclude that treatment of Cy/+ rats with calcium channel blockers increases activity of the B-Raf/MEK/ERK pathway accelerating cyst growth in the presence of endogenous cAMP, thus exacerbating renal cystic disease.

Renal enlargement in polycystic kidney disease (PKD) is caused by the proliferation of mural epithelial cells and transepithelial fluid secretion into the cavities of innumerable cysts. Arginine vasopressin (AVP) stimulates the proliferation of human PKD cells in vitro via cAMP-dependent activation of the B-Raf/MEK (MAPK/ERK kinase/extracellular signal-regulated kinase (ERK) pathway. ERK activity is elevated in cells that line the cysts in animals with PKD, and AVP receptor antagonists reduce ERK activity and halt disease progression. For suppression of the effect of AVP physiologically, water intake was increased in PCK rats, a model of PKD, and the effect on renal morphology, cellular mechanism, and function was determined. The addition of 5% glucose in the drinking water increased fluid intake approximately 3.5-fold compared with rats that received tap water. In PCK rats, increased water intake for 10 wk reduced urinary AVP excretion (68.3%), and urine osmolality fell below 290 mOsmol/kg. High water intake was associated with reduced renal expression of AVP V2 receptors (41.0%), B-Raf (15.4%), phosphorylated ERK (38.1%), and proliferating cell nuclear antigen-positive renal cells (61.7%). High water intake reduced the kidney/body weight ratio 28.0% and improved renal function. Taken together, these data demonstrate that water intake that is sufficient to cause persistent water diuresis suppresses B-Raf/MEK/ERK activity and decreases cyst and renal volumes in PCK rats. It is suggested that limiting serum AVP levels by increased water intake may be beneficial to some patients with PKD.

Androgens have been implicated in mediating disease escalation in autosomal dominant polycystic kidney disease (ADPKD). Dihydrotestosterone (DHT), an agonist, and flutamide (FLT), an antagonist, were administered to Han:SPRD rats with ADPKD, and the role of androgen receptor (AR) abundance and activation on the enlargement and function of cystic kidneys was evaluated. Renal AR abundance determined by immunoblots in 8- to 10-wk-old Cy/+ male rats was naturally increased four-fold above that of littermate +/+ controls. In male Cy/+, castration decreased AR abundance below control +/+ by −89.4%, and AR expression within cyst mural epithelial cells was strikingly decreased. Castration of Cy/+ male rats also reduced the usual increases in kidney weight by −49.7%, kidney cyst area by −34.0%, and serum urea nitrogen by −72.8%; these indices were restored to precastration levels by DHT. In Cy/+ male rats, FLT administration reduced the increase in kidney weight by −27.6% and serum urea nitrogen by −53.7% and decreased the increment in AR expression by −84.2% in comparison with untreated +/+ controls. There was no effect of FLT in female rats. Immunoblot expression of phospho–extracellular signal-regulated kinase 1/2 (P-ERK) and B-Raf, key intermediates in the mitogen-activated protein kinase pathway that are abnormally elevated in Cy/+, was unaffected by castration and/or administration of DHT or FLT. AR was not expressed in renal epithelial cell nuclei of androgen-deficient rats but was displayed in most tubule and mural cyst cell nuclei of androgen-replete rats. In androgen-deficient Cy/+, 80.6% of renal epithelial cells that had entered the cell cycle (proliferating cell nuclear antigen positive) also expressed P-ERK. In androgen-replete rats, proliferating cell nuclear antigen–positive cells co-expressed AR (12.7%), P-ERK (36.4%), and P-ERK + AR (45.0%); 5.9% were probably stimulated by other mitogenic mechanisms. It is concluded that androgens potentiate renal cell proliferation and cyst enlargement through ERK 1/2 -dependent and ERK 1/2 -independent signaling mechanisms in Han:SPRD. It is suggested that the basal rate of cell proliferation is determined by ERK 1/2 signaling to a major extent and that androgens have additive effects.

Cyclic nucleotides (cAMP and cGMP) phosphodiesterase (PDE) activities and expression are altered in the cardiac muscle of cardiomyopathic heart failure, and PDE inhibitors improve the abnormal muscle condition through changing the cyclic nucleotide concentration. These observations prompted us to investigate the role of calmodulin (CaM) in the regulation of cyclic nucleotide PDE activities, and moreover to study the modulation of the PDE isozymes in heart failure, using cardiac muscles of cardiomyopathic hamster. The CaM concentrations in the heart muscle of the normal control and cardiomyopathic hamsters (each of three to four hamsters) varied with cell fraction and with the age of the animal. The CaM concentrations in the soluble fraction obtained from cardiomyopathic hamster tissue were significantly increased at 25 and 32 weeks of age (2.02 +/- 0.62 microg/mg protein (mean +/- S.E.), and 3.21 +/- 0.95) compared with that obtained from the control (0.60 +/- 0.04) or cardiomyopathic (0.95 +/- 0.12) hamsters at 8 weeks of age. The solubilized PDE isolated from the hamster heart muscle (three or four hamsters in each age) by column chromatography on diethylaminoethyl (DEAE)-cellulose revealed three peaks of activity, which may correspond to the isozymes of PDE classified recently, namely PDE I, II, and III. These three peaks of activity, particularly peak III, seen in the soluble fraction of cardiomyopathic hamster heart declined in proportion to the age of the animal compared with that of the control hamster heart. In the cGMP-PDE assay system, the concentration of CaM inhibitor W-7 required for 50% inhibition (IC(50)) of PDE I, II, and III peak activities was 140, 29, and 46 microM, respectively, suggesting that PDE II is more sensitive to W-7. These results suggest that alteration in these isozyme activities accompanied with changes of CaM concentration may influence the cardiac muscle contractility in cardiomyopathic hamster via changes of cyclic nucleotide concentration.

Renal activation of extracellular signal-regulated kinase in rats with autosomal-dominant polycystic kidney disease. Background Abnormal proliferation of renal tubule epithelial cells is a central factor in the biogenesis and sustained expansion of cysts in autosomal-dominant polycystic kidney disease (ADPKD). Recent evidence from in vitro studies of human cyst wall epithelial cells has implicated a role for the mitogen-activated protein (MAP) kinase pathway in this aberrant proliferation. To determine the extent to which this signaling pathway is involved in cyst pathogenesis in vivo, we measured the expression of select components of the MAP kinase cascade in Han:SPRD rats with ADPKD at an early stage of the disease. Methods Kidneys of 8-week-old normal Han:SPRD rats (+/+) or rats heterozygous (Cy/+) for ADPKD were examined by Western blot analysis and immunohistochemistry to determine the expression of extracellular-regulated kinase (ERK), phosphorylated ERK (P-ERK), Raf-1 (MAPKKK), phosphorylated Raf-1 (P-Raf-1), B-Raf, Rap-1 and phosphorylated protein kinase A (P-PKA). Results P-ERK was expressed to a greater extent in Cy/+ kidneys (3.74 ± 1.07 fold) than in normal kidneys, whereas ERK abundance was not different. P-Raf-1 levels were higher in Cy/+ than in +/+ kidneys (1.53 ± 0.08 fold) consistent with upstream stimulation of receptor tyrosine kinase. B-Raf and Raf-1 abundances were greater in Cy/+ than in +/+ (1.74 ± 0.25 and 1.27 ± 0.08 fold, respectively). In Cy/+, immunohistochemistry showed increased P-ERK and B-Raf expression in the abnormal mural epithelial cells within cysts. These findings, together with the detection of P-PKA and the small G protein, Rap-1, in cyst epithelial cells, implicate a potential role for cyclic adenosine monophosphate (AMP) in the activation of ERK in ADPKD cells. Conclusions We conclude that the MAP kinase pathway is activated to the level of ERK in the abnormal mural epithelial cells lining cysts in animals with a dominantly inherited type of polycystic kidney disease. We suggest that cAMP, acting through PKA, Rap-1 and B-Raf, may contribute to the activation of ERK in a way that complements receptor tyrosine kinase-mediated agonists in the promotion of cyst enlargement.

Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary renal disorder in humans. Hypertension is one of the major complications, and its control might affect the renal survival and disease mortality. Suitable antihypertensive agents have been discussed based on clinical and animal studies, but no definitive conclusion has been reached. Generally, therefore, all antihypertensives are indiscriminately treated as if providing the same level of blood pressure control. In this study, the blood pressure control of two antihypertensives was investigated using a rat model of ADPKD in humans. Twenty-four male Hannover-Sprague Dawley (Han:SPRD) rats were divided into three groups: a group receiving amlodipine (6 mg/day), a group receiving benazepril (6 mg/day) and an untreated control group. Blood pressure, body weight, and urinary protein excretion were regularly measured up to week 52. Amlodipine and benazepril significantly decreased blood pressure and urinary protein excretion to the same degree. Moreover, a remarkably prolonged survival rate was observed in both groups (at week 52, the survival rate was 25% in controls, 50% in the amlodipine group, and 50% in the benazepril group). Examination at autopsy revealed that enlarged cysts were prevalent in the renal tissue of both experimental all three groups, suggesting that the cystic disease had reached the end-stage in all the animals. In conclusion, both amlodipine and benazepril significantly improved blood pressure control, urinary protein excretion, and survival rate, possibly due to their enhancement of renal survival. (Hypertens Res 2002; 25: 939-943)

Background: Atopic dermatitis is considered to be developed by the IgE-mediated immediate allergy and by the delayed hypersensitivity to causative allergens. We have previously reported that IgE-mediated type I allergy to mites contributed to the development of skin eruptions on atopic model mice (NC mice). Objective: This time, we studied the delayed hypersensitivity skin reaction to mites in NC/F mice. Methods: We conducted 48-hour closed patch testing with Myocoptes musculinus (kekuidani) that is a parasite in NC/F mice and BALB/C mice. Results: At both the 48- and 72-hour readings, 7 (87.5%) out of 8 NC/F mice tested showed positive reactions to M. musculinus. All BALB/C mice showed negative reactions to M. musculinus. All animals showed negative reactions to white petrolatum. Conclusion: Our previous data and results of this study give positive proof that both IgE-mediated immediate allergy and cell-mediated delayed hypersensitivity to a mite antigen contribute to the development of skin eruptions on NC/F mice resembling human atopic dermatitis.

A polycystic kidney rat model is being established from a Crj:CD (SD) rat strain. Unlike existing animal models of polycystic kidney disease, this mutant rat has a completely polycystic liver. Mating experiments revealed that the phenotype is controlled by an autosomal recessive gene. We propose that this gene be tentatively called the "rpc" gene.

The Han:SPRD strain is an SD-background strain known to be a model of polycystic kidney disease (PKD) expressed through an autosomal dominant gene (Cy). However, different genotypes of this strain cannot be identified in the neonatal period. First, to establish an accurate method of determining the genotypes (Cy/Cy, Cy/+, +/+) which cause different disease progressions, we used polymorphic markers on rat chromosome 5. PCR products of tissue DNA templated with D5Rat9 showed distinct patterns on electrophoresis indicating three genotypes. Second, to determine whether the same locus plays a major role in expressing PKD, we performed linkage analyses in a [BN x (BN x Han:SPRD)F1] backcross. Cy/Cy and Cy/+ also caused PKD in a BN background. In this backcross, we discovered that D5Rat11 is located closer to the Cy locus than D5Mgh10, which is regarded as one of the closest loci. We conclude that D5Rat9 and D5Rat11 are useful markers for determining the presence of the Cy allele, which is regarded as the gene responsible for PKD.

We analyzed protein fractions extracted from the spinal cord of the motor neuron degeneration (Mnd) mouse, a mutant that exhibits progressive degeneration of lower spinal motor neurons, by one- and two-dimensional polyacrylamide gel electrophoresis (PAGE) after solubilization of the tissue with medium containing sodium dodecyl sulfate (SDS)-urea during growth of the animal, in comparison with those of age-matched controls (C57BL/6). Several protein spots were detected around a region of pI 5.6-6.0 and molecular mass of 35-50 kDa in Mnd spinal cord tissue on the two-dimensional PAGE separation profile with Coomassie brilliant blue staining, while only a few spots around the same region were found in the control spinal cord. These spots were all immunoreactive with an antibody against glial fibrillary acidic protein (GFAP), a cytoskeleton filamentous protein specific to astroglial cells. The protein spot with molecular mass of 50 kDa showed immunoreactivity with anti-GFAP antibody, had a blocked amino-terminus, and is assumed to be intact GFAP. Several protein spots with slightly smaller molecular masses of 35 to 48 kDa lacked the head domain of the GFAP molecule as a result of cleavage at the 29th and 56th residues from the amino terminus. In Mnd spinal cord tissue, the densities of the immunoreactive GFAP bands with smaller molecular masses increased with development, and became dominant at the time of the appearance of behavioral paralytic gait around 6 to 7 months of age. These results suggest that the increased GFAPs devoid of head domains are related to the degenerative loss of motor neurons in the Mnd spinal cord. Histopathological and GFAP immunohistochemical examination of Mnd spinal cord preparation demonstrated progressive degenerative loss of motor neurons, and considerable increases in number of GFAP-stained astrocytes in the ventral horn at 7 to 9 months of age. These processes of degenerative loss of motor neurons and proliferation of reactive astrocytes with increased levels of fragmented GFAP in the Mnd spinal cord during development seem to be characteristic and preceded the deterioration of motor activities in this animal model of amyotrophic lateral sclerosis.

Oxidative stress is suggested as a significant causative factor for pathogenesis of neuronal degeneration on spinal cord of human ALS. We measured some enzymic activities implicating neuronal degeneration process, such as cytochrome c oxidase (CO), superoxide dismutase (SOD), and transglutaminase (TG) in spinal cord of an animal model of ALS, motor neuron degeneration (Mnd) mouse, a mutant that exhibits progressive degeneration of lower spinal neurons during developmental growth, and compared them with age-matched control C57BL/6 mice. CO activity in Mnd spinal cord decreased during early postnatal period, while SOD activity reduced in later stage. In Mnd tissue, TG activity in lumbar cord was increasing during early stage, but tended to decline in later period gradually. These biochemical alterations became evident prior to the appearance of clinical motor dysfunction which were observed in later stages of development in Mnd spinal cord.

BUF/Mna strain rats spontaneously develop slowly progressing mild-moderate muscle atrophy of extensor digitorum longus, tibialis, and extraocular muscles, which consist mainly of fast-twitch type fibers, at nearly 100% incidence. They have lighter extensor digitorum longus muscles than soleus muscles, when alive for more than 6 weeks. Genetic segregation of the development of the muscle atrophy was studied by crossing the BUF/ Mna strain with three other strains, ACI/NMs, WKY/NCrj, and BDIX, which were free of muscle atrophy. Two autosomal dominant susceptible genes, Mas-1 and Mas-2, determine the development of the muscle atrophy in these combinations of crosses.

Although different gait analysis methods such as Walking Track Analysis exist, they cannot be used to demonstrate the physical condition of mice with specific gait disorder characteristic. Therefore, we developed a new method for the gait analysis of such mice to accurately assess hind limb angle based on the pelvic axis.We established and verified a gait analysis method capable of pelvic axis-based limb angle measurement by video-recording the gait of a control mice group (C57BL/6J(B6)) and three ataxic mice (ataxic B6-wob/t, Parkinson's disease model (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine treated (MPTP)), and cerebellum hypoplasia (cytosine-β-d-arabinofuranoside treated)) from the ventral side.The assessed hind limb angles of B6-wob/t and MPTP-treated mice were significantly wider than B6 mice (p0.01). Moreover, we could draw separating lines with slopes of minus one that could separate the data of each group in the scatter plot of the normalized hind limb step width and angle.We found no significance when we applied the already existing nose-tail method for the analysis of the hind limb angles of B6 and B6-wob/t mice. In the nose-tail method, since the whole body axis of the trunk varies while the trunk of the mouse is laterally bent changing the hind limb angle, B6 and B6-wob/t mice could not be differentiated. However, the two mice groups could be differentiated by the pelvic axis-based gait analysis method.The pelvic axis-based gait analysis method is promising and valid for mice with gait disorder.

The murine polycystic kidney disease gene, pcy, is an autosomal recessive trait located on chromosome 9. To determine the genetic locus of pcy, 222 intraspecific backcross mice were obtained by mating C57BL/6FG-pcy and Mus molossinus. Restriction fragment length polymorphism analysis of 70 of the 222 backcross progeny showed that pcy, dilute coat color (d), and cholecystokinin (Cck) were located in the order d--pcy--Cck from the centromere. Simple sequence repeat length polymorphism analysis of DNA of all 222 backcross mice was carried out using four markers which were located near the central regions of d and Cck. One and eight recombinations were detected between D9Mit24 and pcy and between D9Mit16 and pcy, respectively. However, no recombinant was observed among pcy, D9Mit14, and D9Mit148. These findings strongly suggest that D9Mit14 and D9Mit148 are located near the pcy gene and are good markers for chromosomal walking to this gene.

Apical mislocation of the ubiquitous transport enzyme Na,K-ATPase has been implicated as a feature of cyst development in in vitro studies of human polycystic kidney disease (PKD) epithelia. We undertook an immunohistochemical study of murine glucocorticoid-induced PKD, the pcy mouse, the cpk mouse, and the diphenylthiazole (DPT)-induced rat models of PKD to determine if this feature was common to these models of cyst development. Distribution of Na,K-ATPase was determined with a polyclonal anti-Na,K-ATPase antibody and a nickel-silver-enhanced peroxidase color development system. Results were documented objectively with densitometric techniques. Control animals appropriate to the age, strain, and species of the experimental groups demonstrated the expected polar distribution of Na,K-ATPase to the basolateral surface. This distribution was more marked in mature animals. Tubular dilatation and cystic change, however, were associated with increased apical Na,K-ATPase in all models. The murine models demonstrated decreased basolateral staining for Na,K-ATPase compared with controls, although this was not a feature of the DPT rat model. Abnormal location of Na,K-ATPase is a shared feature of a variety of animal models and human PKD. This may contribute to abnormal fluid and electrolyte flux favoring cyst formation or may represent expression of a less differentiated renal tubule epithelial phenotype.

Cyst fluids from subjects with autosomal dominant polycystic kidney disease (ADPKD) cause polarized monolayers of MDCK cells to secrete fluid toward the apical compartment in vitro. To determine the extent to which secretagogue accumulation may be a general feature of polycystic diseases, cyst fluid from mice with a slowly progressive form of hereditary PKD (DBA/2FG-pcy/pcy) was added to polarized MDCK monolayers. Basolateral application of cyst fluids (diluted with culture medium to 15% final concentration) from 13 different animals 16 to 35 weeks old increased the fluid secretion rate from a baseline of 0.023 +/- 0.003 to 0.111 +/- 0.017 microL/cm2/h (P0.005). There was a direct relation between the concentration of cyst fluid and the rate of net fluid secretion. The secretory activity of cyst fluid was not altered by pronase treatment or boiling. Cyst fluid (10%) added to the basolateral surfaces of polarized MDCK monolayers for 24 hours increased cell cyclic adenosine monophosphate (AMP) levels from a baseline of 6.3 +/- 0.2 to 17.3 +/- 0.3 pmoles/monolayer (n = 3, P0.05). The capacity of cyst fluid to increase cyclic AMP levels was not changed by pronase treatment or boiling. There was a direct relation between the level of cellular cyclic AMP and the rate of transepithelial fluid secretion caused by cyst fluid. Cyst fluid increased thymidine incorporation by Madin-Darby canine kidney (MDCK) cells to an extent equal to that caused by epidermal growth factor and caused MDCK cells to form cysts in collagen matricies.(ABSTRACT TRUNCATED AT 250 WORDS)

The DBA/2FG-pcy mouse has a form of slowly progressive kidney disease that appears similar in many respects to that seen in the autosomal dominant form of human polycystic kidney disease. This study was designed to assess how the expression of extracellular matrix component genes is regulated in a model of murine polycystic kidney disease and control DBA/2 mice at 8, 16, and 30 weeks of age. The mRNA levels encoding for collagen IV, the B1 and B2 chains of laminin, heparan sulfate proteoglycan, fíbronectin, and collagens I and III increased with the progression of cystic lesions in the kidney of DBA/2FG-pcy mice. At 30 weeks of age, mRNA levels for collagen IV, laminin B1 and B2, heparan sulfate proteoglycan, fíbronectin, and collagens I and III were increased 8.1-fold, 7.0-fold, 7.0-fold, 9.8-fold, 7.0-fold, 5.5-fold, and 5.4-fold, respectively, compared to those of control DBA/2 mice. An immunofluorescence study revealed the irregular staining for collagen IV, laminin, heparan sulfate proteoglycan, and collagens I and III around the cysts. These data suggest that changes in the expression of basement membrane components and interstitial collagens are associated with the development of polycystic kidney disease.

The objective of these studies was to examine the effects of early dietary protein restriction on disease progression and survival in the DBA/2FG-pcy (pcy) mouse model of polycystic kidney disease. Male pcy mice of 70 days of age were fed either a normal protein (NP, 25% casein) or a low-protein (LP, 6% casein) diet for 105 days. At the end of the dietary treatment, kidney weight, kidney weight relative to body weight and kidney water contents were almost 50% lower, and relative renal phospholipid and triglyceride contents were almost 50% higher, in mice fed the LP diet, indicating a marked reduction in the progression of cystic disease. Morphometric analyses also revealed a lower total and percent cyst area in kidneys derived from mice on the LP compared with the NP diet. There were no significant differences in final body weight, urine volume and osmolality, GFR, proteinuria, or plasma levels of protein and urea between these two groups. In a second study, it was found that all mice fed an NP diet from 70 days of age onward had died by 310 days of age, compared with a 42% survival rate in LP-fed mice at this age. Overall, the mean lifespan for pcy mice on the LP diet was 24% longer than that for those mice on the NP diet (310 +/- 20 versus 251 +/- 16 days; P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

The effects of ethanol on a liver tumor which was transplanted into athymic nude mice were investigated. The original liver tumor was obtained from a F344 rat, initiated with diethylnitrosamine (DEN), and subsequently administered 2-acetyl-aminofluorene (2-AAF), and established as a tumor line in rnu/rnu rats. Pieces of serially transplanted liver tumor were inoculated into 34 ICR nude, 5-week-old, mice. After one week, these were divided into two groups, one (Group 1) receiving a 0.2ml injection of ethanol in the transplanted and the afer (Group 2) given 0.2ml saline. Group 3, without the tumor transplanted was administered ethanol as a control. Subgroups of animals were killed at days 2, 5, 10, and 30. In group 1, at day 2 after the ethanol injection areas of tumor showed severe necrosis with crust formation. In contrast, those not receiving the ethanol injection demonstrated intact transplants. In group 1, necrotic portions were gradually absorbed and development of tumors was apparent by day 30, but the sizes of individual lesions were smaller than in the group given saline alone. Thus ethanol clearly inhibited the growth of transplanted liver tumor. The results suggest that ethanol injection might be effective as a treatment for hepatocellular neoplasms.

The growth-associated increase in the blood glucose level of animals with Type 2 diabetes is inhibited by moderate hyperbaric exposure at 1.25 atmospheres absolute (ata) with 36% oxygen, presumably due to an increase in oxidative metabolism. However, there are no data available regarding the effect of moderate hyperbaric oxygen (HBO) on diabetes-induced cataracts.Four-week-old mice with Type 2 diabetes and cataracts were exposed to 1.25 ata with 36% oxygen, 6 h daily, for 12 weeks, followed by normal conditions at 1 ata with 21% oxygen for 16 weeks (cataract + hyperbaric group). Levels of blood glucose and derivatives of reactive oxygen metabolites (dROMs), used as an index of oxidative stress, and the turbidities of the lenses from these mice at 4, 8, 12, 16, and 32 weeks of age were compared with those of control and diabetic (cataract group) mice not exposed to HBO.Non-fasting and fasting blood glucose levels were lower in the cataract + hyperbaric group at 12, 16, and 32 weeks of age than in the age-matched cataract group. The levels of dROMs were lower in the cataract + hyperbaric group at 16 and 32 weeks of age than in the age-matched cataract group. The turbidities of the peripheral and central regions of the lenses were lower in the cataract + hyperbaric group at 12, 16, and 32 weeks of age than in the age-matched cataract group.Hyperbaric exposure at 1.25 ata with 36% oxygen delays cataract development and progression in mice with Type 2 diabetes.

It has been demonstrated that replacing dietary n-6 with n-3 polyunsaturated fatty acids is beneficial in some animal models of renal disease, but not in others. We fed semi-purified diets containing either sunflowerseed oil (containing linoleic acid, 18:2n-6) or fish oil (containing eicosapentaenoic acid, 20:5n-3, plus docosahexaenoic acid, 22:6n-3) to a mouse model of polycystic kidney disease (DBA/2FG- pcy ). Renal phospholipid and triglyceride fatty acid compositions were markedly altered by dietary treatment: 20:5n-3 and 22:6n-3 levels were elevated in the kidneys from mice fed fish oil at the expense of 18:2n-6 and arachidonic acid, 20:4n-6. Despite these lipid alterations, however, survival and proteinuria were not improved by long term fish oil consumption in mice with polycystic kidney disease.

Effects of dietary protein restriction and oil type on the early progression of murine polycystic kidney disease. A paucity of research data exists on the potential for early dietary modification to directly retard cystic growth and proliferation in polycystic kidney disease (PKD). We have therefore examined the relative effects of dietary protein levels and oil type on the progression of disease in a murine model of PKD. In the first study, weanling DBA/2FG- pcy ( pcy ) mice were fed either a normal (NP), 25%, or low (LP), 6%, casein diet with 10% of either sunflower seed oil (SO) (containing n-6 fatty acids), or fish oil (FO) (containing n-3 fatty acids), in a 2 × 2 design. At the end of the dietary treatment, kidney weight relative to body weight was higher in mice on the NP diets. In addition, kidney phospholipid to kidney weight (µmol/g) was lower in pcy mice on NP diets, indicating that the increased kidney size was largely due to increased cyst development. Replacement of dietary SO with FO resulted in alterations in renal phospholipid fatty acid compositions: 18:2 n-6, 20:4 n-6, and 22:5 n-6 were lower, and 20:5 n-3, 22:5 n-3, and 22:6 n-3 were higher in FO-fed animals. No effect of dietary lipid type on disease progression was noted, however. In a second study, morphometric analysis revealed an 11% lower percentage cyst area and a 46% lower total cyst area (mm 2 ) in kidney sections derived from mice on LP diets compared to NP diets. These results indicate that early dietary protein restriction in PKD prior to clinical manifestation of symptoms of the disease may have a significant impact on the pathogenesis of PKD.

The mass amounts and fatty acid compositions of the second messenger, diacylglycerol, have been shown to be altered in several disease states and in transformed cells. In the present study, the mass amounts and fatty acid compositions of renal diacylglycerol were determined in a mouse model of polycystic kidney disease. Kidney diacylglycerol (nmol/100 nmol phospholipid) was elevated by 21% in diseased mice compared to normal controls. Diseased kidneys were also characterized by higher levels of stearic (18:0) and arachidonic (20:4n-6) acids and lower levels of eicosenoic (20:1) and docosapentaenoic (22:5n-6) acids in the diacylglycerol fraction. Furthermore, the level and fatty acid compositions of kidney diacylglycerol in the mice with polycystic kidney disease were modified by altering dietary protein levels and lipid type. Compared with high protein diets, low protein diets were associated with both higher renal diacylglycerol levels (overall by 31%), and a retardation of renal cystic disease progression. Substituting dietary sunflowerseed oil with fish oil resulted in markedly lower levels of n-6 fatty acids and higher levels of n-3 fatty acids in kidney diacylglycerol. It remains to be determined what effect these changes in diacylglycerol level and type may have on protein kinase C-mediated events associated with biochemical defects found in polycystic kidney disease. These findings raise the possibility that diet-induced alterations of diacylglycerol mass and fatty acid compositions in vivo could be utilized to modify intracellular signalling events that accompany certain pathophysiologic conditions.

Polyphosphoinositide isomers have been demonstrated to be important mediators of cell proliferation in vitro. The present study demonstrates, for the first time, the in vivo formation of the novel isomer, phosphatidylinositol(3)phosphate, in the kidney and liver of intact animals following intraperitoneal administration of [3H]myo-inositol. The formation of renal [3H]phosphatidylinositol(3)phosphate relative to total [3H]phosphatidylinositol-phosphate was positively correlated with cyst proliferation and renal enlargement in a murine model of polycystic kidney disease. Furthermore, despite no difference in the formation of renal [3H]phosphatidylinositol(4)phosphate, a markedly lower accumulation (by 48%) of [3H]phosphatidylinositol(4,5)bisphosphate was observed in the diseased animals as compared to controls. These results indicate that further studies on the in vivo formation of specific polyphosphoinositide isomers in disease states characterized by abnormal growth and oncogene expression are warranted.

Mechanisms for the development of anemia and the effects of recombinant human erythropoietin (r-HuEPO) on hematological parameters were studied in new congenital adult type polycystic kidney (DBA/2FG-pcy) mice. The majority of DBA/2FG-pcy mice showed progressive anemia and an elevation of blood urea nitrogen, while a minority showed progressive anemia following polycythemia. Kidneys with numerous cysts in the cortex and medulla occupied virtually the entire abdominal cavity, and the combined kidney weight taken as a percentage of body weight reached 13.5% in the DBA/2FG-pcy mouse. The osmotic fragility of DBA/2FG-pcy mice erythrocytes was significantly increased compared with that of normal control mice. In addition, two-fold increases in serum EPO levels, determined by radioimmunoassay, and a decreased number of colony forming unit-erythroid (CFU-E) were observed in the DBA/2FG-pcy mice. The administration of r-HuEPO during anemia significantly increased the red blood cell count, hemoglobin concentration, hematocrit and reticulocyte percentage in a dose-dependent manner. These findings indicate that anemia in the DBA/2FG-pcy mouse is due to increased fragility of erythrocytes, a deficiency in EPO for the degree of anemia and a decreased number or a decreased response of erythroid progenitor cells. We suggest that the DBA/2FG-pcy mouse is a useful spontaneous model of chronic progressive renal failure.

Two murine models of polycystic kidney disease (PKD) in humans are currently available: the infant-type cpk in mice and the adult-type pcy mutation in mice. Our linkage analysis was to determine whether these genes are allelic forms of the same gene, or infant-type and adult-type PKD resulting from homozygous and heterozygous mutation, as in the rat Cy gene. We found that the pcy gene in the mice was linked with the d gene on chromosome 9, but the cpk gene was not. A segregation test indicated that the two genes are inherited independently. This indicates that the cpk and pcy genes are not alleles and that the genetic mechanism of PKD pathogenesis in the mouse is different from that in the Cy rat.

DBA/2FG-pcy and C57BL/6FG-pcy congenic strains were established by transferring the polycystic kidney disease gene, pcy, to DBA/2 and C57BL/6 mice. We carried out pathological and hematological examinations of these strains at 4, 8, 16 and 30 weeks of age. In DBA/2FG-pcy mice more than 8 weeks of age, macroscopic renal cysts were observed on the surface of both kidneys. Their kidneys weight was significantly greater than in DBA/2 mice at all ages examined. Microscopic renal cysts were evenly distributed at 4, 8 and 16 weeks of age. At 30 weeks of age, the kidneys were filled with numerous polycysts. In C57BL/6FG-pcy mice, no macroscopic renal cysts were found until the animals were 30 weeks old, and the weight of their kidneys was greater than in B6 mice of the same age. From 8 weeks of age on, a limited number of microscopic renal cysts was observed, and many renal cysts were found adjacent to the enlarged Bowman's capsules. With age, the red blood cell count and hematocrit level decreased while the platelet count increased in both strains, with greater changes occurring in DBA/2FG-pcy mice than in C57 BL/6FG-pcy mice. These findings demonstrate that polycystic kidney disease exhibits strain differences in animals with a DBA/2 and C57BL/6 background. Our results suggest that phenotypic expression of the pcy gene in the mouse depends on genetic background, and that variations in the severity of human polycystic kidney disease may be explained, at least in part, by individual differences in genetic background.

Proton magnetic resonance imaging (MRI) and localized spectroscopy techniques were used to study polycystic kidney disease (PKD) in DBA 2FG-pcy (pcy) mice, which are an animal model for the adult form of human PKD. A volume selective spectroscopy (VOSY) method was used to obtain localized proton spectra as well as apparent T1 and T2 relaxation times of the kidneys of either pcy or DBA 2FG normal (DBA) mice. Localization of the proton spectra was based on spatial coordinates determined from the proton images. Increases in apparent kidney T1 and T2 relaxation times were observed for pcy mice in comparison to those measured in DBA mice. Localized kidney T1 values from pcy mice were found to range from 799 to 1395 msec whereas DBA mice kidney T1 values were 617 to 774 msec. Localized T2 values measured from pcy mice kidneys ranged from 90 to 172 msec in comparison to kidney T2 values of 50 to 72 msec for DBA mice. The onset of cyst formation in the kidneys of pcy mice as a function of age was also studied. As early as 4 to 5 weeks of age it was possible to detect in vivo changes in pcy mice kidney T1 and T2 values.

Background: Some reports have discussed the synergic effects of angiotensin II receptor blockers and calcium channel blockers on vascular injury or microalbuminuria. The present study examined the effects of combination treatment with olmesartan and azelnidipine on polycystic kidney disease in a mouse model (DBA/2-FG pcy mouse) and its mechanisms. Methods: The mice were divided into the following groups: combination treatment (n = 21), olmesartan treatment alone (n = 23), azelnidipine treatment alone (n = 29) or untreated (n = 26). Mean blood pressure and kidney weight were measured at 4 and 8 weeks after the treatment. Renal expression of angiotensin II, gp91, nitrotyrosine and endothelial NO synthase (eNOS) were examined by immunostaining. In addition, extracellular signal-regulated kinase activation was evaluated by Western blotting. Results: Olmesartan decreased the numbers of angiotensin II and gp91-positive cells, mainly macrophages, and cyst size at 4 weeks. However, only combination treatment suppressed cell infiltration, extracellular signal-regulated kinase activation and interstitial fibrosis with a significant change in the kidney weight/body weight ratio. The azelnidipine and combination treatment increased the numbers of interstitial eNOS-positive cells. Conclusion: The combination treatment protects against cyst enlargement in polycystic kidney disease by suppressing interstitial inflammation, fibrosis and oxidative stress by upregulating eNOS expression during disease course.

The expression of mitogen-activated protein kinases (MAPK) in DBA/2-pcy/pcy (pcy) mice, a murine model of polycystic kidney disease was investigated. Proliferating cell nuclear antigen-positive cells were recognized in cyst epithelium from embryonic day 14.5 to 25 wk of age. Extracellular signal-regulated kinase (ERK) was expressed in the renal tubules of control and pcy mice, but stronger immunostaining was observed in cyst epithelium. Phosphorylated ERK was detected only in pcy mice and was localized predominantly in the cysts. p38 MAPK (p38) was no longer expressed after birth in controls but was detected in the cyst epithelium and in occasional tubular cells of pcy mice at all stages examined. c-Jun N-terminal kinase (JNK) was expressed in all tubular segments of controls after neonatal day 7, whereas in pcy kidneys, tubules became positive for JNK after 8 wk, and the cysts expressed little JNK. Administration of an oral MAP/ERK kinase inhibitor, PD184352, 400 mg/kg per d, to 10-wk-old pcy mice daily for the first week and then every third day for 6 additional weeks significantly decreased BP, kidney weight, serum creatinine level, and water intake and significantly increased urine osmolality. The cystic index and expression of phosphorylated ERK and ERK were significantly lower in PD184352-treated pcy mice. These results demonstrate that the expression of MAPK is dysregulated in cyst epithelium and that inhibition of ERK slowed the progression of renal disease in pcy mice.

Huntington's disease (HD) is caused by a mutation causing expanded polyglutamine tracts in the N-terminal fragment of huntingtin. A pathological hallmark of HD is the formation of aggregates in the striatal neurons. Here we report that ageing human huntingtin knock-in mice expressing mutant human huntingtin contained neuronal huntingtin aggregates, as revealed by immunohistochemical analysis. In heterozygous knock-in mice with 77 CAG repeats, aggregates of N-terminal fragments of huntingtin were specifically formed in nuclei and neuropils in the striatal projection neurons, and in neuropils in their projection regions. This aggregate formation progressed depending on age, became interacted with proteolytic or chaperone proteins, and occurred most prominently in the nucleus accumbens. These mutant mice demonstrated abnormal aggressive behavior. In homozygous knock-in mice, heavy deposits of intranuclear and neuropil aggregates were detected, which extended to other regions; and characteristic large perikaryal aggregates were also found in the affected neurons. However, cell death was not observed among the striatal and affected neurons of these mutant mice. Our results indicate that the polyglutamine aggregates do not necessarily correlate with neuronal death. These human huntingtin knock-in mice should be useful to provide an effective therapeutic approach against HD.

SUMMARY 1. The present study was carried out to explain the resistance of rats injected subcutaneously with risperidone, the atypical antipsychotic drug, for 21 consecutive days at 0.1 mg/kg per day (a dose equivalent to the one used for patients) to result in an excessive bodyweight despite the increase in diet-uptake in rats against risperidone-induced decrease in body temperature. 2. Rectal temperature measurements were made in 8-week-old male Sprague-Dawley rats maintained under standard laboratory conditions using a 12 h daylight cycle. A s.c. injection of risperidone (0.05 mg/kg) produced hypothermia in rats, which was observed during the daily injection for 21 consecutive days. 3. Sera, white and brown adipose tissues, skeletal muscle and liver were extracted from 8-week-old male Sprague-Dawley rats injected subcutaneously with risperidone (0.01 or 0.1 mg/kg per day) or a vehicle for 21 consecutive days. Serum levels of lipids, ketones and thyroid hormone were measured. The mRNA expression levels in these tissues and organs of the genes encoding the substances involved in heat production and/or lipid metabolism were investigated by using quantitative real-time polymerase chain reaction amplification. 4. Serum nonesterified fatty acid levels in risperidone 0.1 mg/kg per day s.c. injected rats were significantly lower than those in vehicle-injected ones. Serum β-hydroxybutyrate levels in risperidone-injected rats tended to decrease compared with those in vehicle-injected ones. The serum level of neither triiodothyronine nor thyroxine was affected by risperidone s.c. injection at the doses examined, although their values were within normal limits. 5. Risperidone injection (0.1 mg/kg per day) for 21 consecutive days upregulated mRNA expressions in white adipose tissue of uncoupling protein 3 which dissipates energy as heat; peroxisome proliferator-activated receptor (PPAR) γ coactivator 1α which activates mitochondrial biogenesis to expand the oxidative machinery; and PPARα which is necessary for the fat-depletion of adipocytes for thermogenesis. The mRNA of lipogenic enzymes (acetyl-CoA carboxylase α, fatty-acid synthase and glycerol-3-phosphate acyltransferase), hormone sensitive lipase and β1-adrenoceptor were also enhanced in white adipose tissue by the injection of 0.1 mg/kg per day risperidone. 6. These findings suggest that the materials for heat generation in white adipose tissue would be readily supplied, which in turn would reduce a storage of lipids in white adipose tissue resulting in the lower rate of bodyweight gain of rats.

The olfactory bulb (OB) is one of the few structures in the adult mammalian CNS that contains a continuous supply of newly generated neurons in the subventricular zone. Therefore, the balance between the supply of new cells and apoptosis in the OB might determine olfactory function. Lipopolysaccharide-induced tumor necrosis factor (TNF)-α triggers the apoptotic cascade mediated by the TNF/TNF receptor (TNFR) pathway. The present study therefore examines the effect of the propagated innate immune reaction triggered by peripheral lipopolysaccharide on the OB of C3H/HeN mice. Within 2 h of an intraperitoneal injection of lipopolysaccharide, mRNA expression levels of the genes encoding IκB , TNF-α , and TNFR type 1 in the mouse OB were significantly enhanced. Double immunofluorescence microscopy confirmed that almost all TNF-α-immunopositive cells in the OB of the TNF-injected mice were located in the subependymal zone and that they overlapped cells immunostained with antibody against glial fibrillary acidic protein, but not with the antibody against F4/80, an antigenic marker of microglia. The number of TUNEL-positive cells identified exclusively in the granule cell layer was significantly increased in mice injected with lipopolysaccharide and sacrificed at 24 h thereafter. These results suggest that peripheral lipopolysaccharide causes disequilibrium between the supply and disappearance of the cells in the OB, which might lead to olfactory dysfunction.

BACKGROUND: We observed nishikinezumi, cinnamon-coloured (NC)/Fujita (F) mice aged between 5 and 28 weeks. These NC mice have skin eruptions that resemble human atopic dermatitis (AD) under conventional circumstances. OBJECT: We investigated the skin of eruptive and non-eruptive lesions in NC/F mice by using haematoxylin-eosin (H&E) staining, toluidine blue staining and immunohistopathological study with immunoglobulin (Ig)EepsilonRI, CD23, interleukin (IL)-4, IL-5, interferon (INF)-gamma and Ia antigen. RESULTS: Histological examination of the eruptive lesions revealed the perivascular infiltration of many lymphocytes and mast cells into the upper dermis. Intracellular oedema of the epidermis, lymphocyte infiltration into the epidermis and liquefaction degeneration of the basal layer were also observed. The numbers of IL-4 and IL-5 positive cells in the eruptive lesions were larger than those of the non-eruptive lesions. IL-4 and IL-5 positive cells in the eruptive lesions increased weekly. Some IFN-gamma positive cells were observed in the eruptive lesions after 21 weeks. IFN-gamma positive cells were scarce in the skin of both the non-eruptive and eruptive lesions before 21 weeks. Serum IgE increased from 7 weeks to 21 weeks. DISCUSSION: We confirmed that these findings indicated that T helper (Th)2-dominant immunological activation transformed to a Th1-dominant situation. Many IgEepsilonRI positive cells were recognized in the dermis of the eruptive lesions by the time IgE had decreased. We assumed that the dermatitis before 21 weeks was an IgE-mediated allergy. We have previously reported that older NC/F mice had positive patch-test reactions to mites. Because serum IgE decreased after 21 weeks, dermatitis after 21 weeks might be associated more with cell-mediated delayed hypersensitivity than with IgE-mediated immediate allergy.

Dystrophic hamster has been regarded as the useful model animal for Severe childhood autosomal recessive muscular dystrophy (SCARMD). Although, many studies on Dystrophic hamster have utilized the muscular tissue of the trunk, however no study have been analyzed for the masticatory muscle. For this study, we used a Dystrophic hamster (UM-X7.1 Syrian hamster) to histochemically investigate the effect of muscular dystrophy on the masseter muscle. Large and small regenerated muscle fibers, and necrotic fibers were detected almost in all areas. Opaque fiber, hypertrophic fiber with fiber splitting structure and necrotic fiber filled up by mononuclear phagocytes were recognized. The region, in which the mononuclear phagocytic cells infiltrated, showed strong positivity to acid phosphatase, and lysosome enzyme. There were many muscle fibers with reduced levels of succinate dehydrogenase (SDH) activities in the muscle fiber. Some TUNEL-positive cells were confirmed in both necrotic and non-necrotic areas. It was suggested that a part of TUNEL-positive cells are the cells originated from the connective tissue or immunocytes. In this result, histopathologic changes of the masseter muscle of the UM-X7.1 Syrian hamster was similar to muscle of the body trunk in the past reports. As the result, it was suggested that jaw closing movements may be negatively affected caused by the decline of the masseter muscle twitch. And, the point of view by which apoptosis is the trigger for the muscle fiber collapse were not seen in the Dystrophic hamster masseter muscle. We suggest that apoptosis is a one step in the process of regeneration of muscle fibers.

BUF/Mna (BUF) is a rat strain susceptible to spontaneous development of thymomas. We have previously shown that the thymoma susceptibility is controlled principally by a dominant susceptibility gene located on chromosome 7, thymoma susceptibility gene of rat 1 (Tsr1). To generate genetic markers tightly linked to Tsr1, we performed genetically directed representational difference analysis (GDRDA) with three combinations of the tester and driver DNAs. From 124 {ACI/NMs × (BUF × ACI/NMs) F1} backcross rats, 12 rats with the ACI/BUF genotype in the Tsr1 region (A/B rats) and 13 rats with the ACI/ACI genotype in the region (A/A rats) were selected, and their DNAs were pooled, respectively. Three kinds of tester DNAs, i) inbred BUF, ii) (BUF × ACI)F1, and iii) the pool from the A/B rats, were subtracted by the driver DNA prepared from the pool of the A/A rats. The three combinations yielded one, two, and one polymorphic marker(s), respectively. One marker, D7Ncc28, was isolated commonly by the three combinations of subtraction, and another marker, D11Ncc12 was isolated only by the second combination. Linkage analysis demonstrated that D7Ncc28 was located in the 8.3 cM region where Tsr1 has been mapped. The three combinations of subtraction were shown to be almost equally capable of isolating polymorphic markers in a specific chromosomal region.

Epithelial proliferation, extracellular matrix remodeling, and interstitial inflammation are central elements in the pathogenesis of slowly progressive polycystic kidney disorders. Probucol, an antioxidant that lowers plasma cholesterol, has been shown to decrease smooth muscle cell proliferation and macrophage accumulation in blood vessels and to prevent restenosis after coronary angioplasty. We determined in 30-day-old male BDF1-pcy hybrid mice (derived from mating DBA/2FG-pcy and C57BL/6FG-pcy) the effect of probucol administered in the diet (1%) for 200 days on kidney weight relative to body weight (KW/BW), cyst expansion, renal interstitial fibrosis, and serum urea nitrogen (SUN) concentration. Animals were fed a moderately high-protein diet (HPD, 36%) to accentuate the development of renal cysts and to promote interstitial fibrosis. Probucol decreased serum cholesterol from 68 to 16 mg/dL but had no effect on food intake or body weight. Probucol decreased relative kidney size from 4.16% +/- 0.55% to 2.64% +/- 0.12% KW/BW (P < 0.01), SUN from 30.5 +/- 1.8 to 25.9 +/- 1.0 mg/dL (P < 0.05), cystic index from 2.45 +/- 0.11 to 1.36 +/- 0.10 (P < 0.01), and fibrosis index from 2.40 +/- 0.11 to 1.82 +/- 0.08 (P < 0.01). We conclude that probucol ameliorates the progressive deterioration in renal function and structure in pcy mice ingesting a relatively high level of dietary protein.

DBA/2FG-pcy/pcy (D2-pcy) mice are a hereditary murine model of slowly progressive polycystic kidney disease (PKD) and characterized by the persistent excretion of acidic urine, in association with polyuria, after weaning. In this study, the activity of carbonic anhydrase (CA) and it histological distribution in the kidney of D2-pcy mice were investigated by immunohistochemistry. Significantly higher CA activity was detected in the cytosolic, but not membrane, fraction of kidney homogenates in 5-week-old D2-pcy mice than in age-matched, control DBA/2 (D2) mice, and a more rapid rate of urine acidification was noted in 11-week-old mice when acetazolamide, an inhibitor of the enzyme, was administered orally. By immunohistochemistry for the major renal CA isoenzyme (CA II), epithelial cells in the distal straight tubules and the cortical collecting ducts were stained intensely, whereas those of the proximal convoluted tubules had only weak and diffuse staining. The glomeruli, the proximal straight tubules and the ascending thin limb of Henle's loop were almost free from staining. In the cells lining cysts and/or dilated tubules, CA II activity was well preserved, although the staining intensity was considerably reduced in fully-flattened, lining cells of cysts, but no difference was found between D2-pcy and D2 mice in any segmental localization of renal CA II activity. From these results it seems that D2-pcy mice in the early stages of the cystic disease continue to secrete excess protons through the CA-mediated reaction that is stimulated for regulation of acid-base balance in the distal portion of the nephron and the collecting duct in kidney. It also suggests that monitoring urine pH may be useful in predicting the effects of early interventions on the progression of slowly developing renal cysts.

The ultrastructure of the parathyroid gland (PTG) of the UM-X7.1 cardiomyopathic hamster (the UM-X7.1) was qualitatively and quantitatively compared with that of the normal hamster. In the UM-X7.1, the Golgi apparatus and rER were well developed compared with those of the control hamster. Morphometric analysis revealed that the mean values of the Golgi apparatus, rER and large vacuolar bodies were significantly greater in the UM-X7.1 than in the normal hamster and the mean value of lipid droplets was significantly less in the UM-X7.1 than in the normal hamster. Ultrastructurally, we consider that in the UM-X7.1, the synthesis and release of the parathyroid hormone may be activated by an excessive amount of circulating catecholamine, and the functional activity of the PTG may be higher than that in the normal hamster.

The effects of feeding a soy protein isolate or genistein, an isoflavonoid present in soy protein, on cyst development were examined in the DBA/2FG-pcy (pcy) mouse, an accepted animal model of polycystic kidney disease, before the appearance of clinical symptoms. In study 1, 60-day-old male pcy mice were evenly divided into two groups and fed semipurified diets, based on casein or a soy protein isolate (15 g protein/100 g diet) for 90 days. In study 2, the animals were fed a casein-based diet (25 g casein/100 g diet) with or without genistein (0.05 g/100 g diet) for 60 days. In study 1, total kidney weight and kidney weight relative to body weight were significantly reduced (by 24% to 25%) in the animals fed the soy protein-based diet, relative to the casein-fed group, as was kidney water content (by 38%). In addition, mean cyst volume, as measured by morphometry, were lower (by 25%) in kidneys from the soy protein-fed group. No differences were found between these two groups with respect to final body weight, plasma creatinine, and protein content; however, plasma urea values were significantly lower in the soy protein-fed animals. Genistein supplementation of a casein-based diet in study 2 did not reduce the renal enlargement and cyst development associated with progression of polycystic kidney disease. These results suggest that soy protein is effective in retarding cyst development in the pcy mouse and that this beneficial effect may be unrelated to its genistein content. (Am J Kidney Dis 1998 Jan;31(1):55-61)

Evidence from in vitro studies indicates that increased proliferation of epithelial cells and secretion of fluid by these cells may be important factors in the progressive enlargement of renal cysts. The rate of cellular proliferation and fluid secretion by cyst epithelium in vitro can be strikingly accelerated by cyclic adenosine 3'5' monophosphate (cAMP) and agonists that lead to the production of this nucleotide. The extent to which renal cAMP content is increased in polycystic kidneys is unknown. In the current study, we determined the amount of this nucleotide in intact kidneys, cyst fluid, plasma, and urine in nonazotemic mice (DBA/2FG-pcy/pcy) with a slowly progressive form of inherited polycystic kidney disease (PKD). In 45 pcy/pcy mice studied 20, 45, or 70 days after birth, the total kidney cAMP content was 0.22 +/- 0.01, 0.46 +/- 0.02, and 0.90 +/- 0.05 pmol/mg tissue, respectively. By contrast, in 37 control DBA/2J mice the levels of cAMP at identical times remained relatively constant at 0.22 +/- 0.01, 0.21 +/- 0.01, and 0.29 +/- 0.01 pmol/mg tissue, respectively. In 70-day-old nonazotemic pcy/pcy mice with normal serum levels of parathyroid hormone, cAMP generated by the kidneys (nephrogenous cAMP) was 22.9 +/- 2.8 nmol/100 mL creatinine clearance, compared with 6.5 +/- 1.3 in normal animals of the same age (P < 0.001). The cyst fluids of 70-day-old pcy/pcy mice contained a lipid that increased transepithelial secretion of fluid by MDCK monolayers from a baseline of 0.012 +/- 0.002 to 0.136 +/- 0.008 microL/cm2/hr (P < 0.05). This lipid also stimulated cellular proliferation by monolayers of cultured MDCK and LLC-PK1 cells 2.5- and 7.9-fold (P < .05), respectively, and stimulated cAMP accumulation by these cells 1.6- and 2.0-fold (P < .05), respectively. These studies illustrate that renal cAMP production and excretion increase in concert with the cystic enlargement of the kidneys in DBA/2FG-pcy/pcy mice and identify a lipid cAMP agonist in murine renal cystic kidney disease.

Woo et al (Nature 368:750-753) reported that parenteral administration of paclitaxel arrested the striking renal enlargement and prolonged life in C57BL/6J-cpk/cpk mice with a rapidly progressive form of polycystic kidney disease (PKD). In the current study, we sought to determine whether paclitaxel could alter the progression of other forms of hereditary PKD in rodents. Paclitaxel was administered by intraperitoneal injection to C57BL/6J-cpk/cpk mice and Han:SPRD-Cy/Cy rats with rapidly progressive PKD and to DBA/2FG-pcy/pcy mice and Han:SPRD-Cy/+ rats with slowly progressive PKD. Paclitaxel (150 micrograms/wk) prolonged the survival of cpk/cpk mice from 24.5 days to more than 65 days and decreased kidney weight relative to body weight from 16.5% at 21 days of age to 8.2% at more than 65 days of age. Mortality attributable to paclitaxel was 12%. By contrast, the administration of paclitaxel (0.1 to 15 mg/kg/wk) to 7- to 10-day-old Han:SPRD-Cy/Cy rats with rapidly progressive PKD had no effect on the course of the disease; moreover, paclitaxel caused severe side effects and premature death in all the Cy/Cy animals. Heterozygous male Cy/+ rats develop slowly progressive renal enlargement and azotemia. Paclitaxel, administered at 7, 15, or 27 mg/kg/wk to male Cy/+ rats from 4 until 10 weeks of age, reduced body weight gain, had an inconsistent effect on kidney weight relative to body weight, and had no effect on the serum urea nitrogen concentration. Mortality associated with the 7, 15, and 27 mg/kg/wk doses of paclitaxel was 0%, 15.4%, and 28.5%, respectively. DBA/2FG-pcy/pcy mice of either sex developed slowly progressive renal enlargement and azotemia. The administration of paclitaxel (100 to 150 micrograms/wk) from 2 to 10 weeks of age to DBA/2FG-pcy/pcy mice with cystic disease had no effect on the increase in kidney weight or on the level of serum urea nitrogen in comparison to untreated cystic animals. Mortality associated with 100- and 150-micrograms/wk doses of paclitaxel was 0% and 20%, respectively. We conclude that paclitaxel diminished the rate of renal enlargement and increased the life span of cpk/cpk mice but not Cy/Cy rats with rapidly progressive forms of PKD. Paclitaxel had no apparent benefit in Cy/+ rats nor pcy/pcy mice with slowly progressive PKD. On the basis of these studies in rodents, it appears that paclitaxel has limited potential usefulness as a therapeutic agent in the treatment of PKD.

The A/J inbred strain of mice spontaneously develops cleft tip and/or palate (CL/P). Ovarian transplantation and several test-matings with C57BL/6 strain mice (0% CL/P) were performed to investigate a relationship between mother and fetus In regard to this order. The fetuses obtained showed that regardless of whether the genetic background of the mother was A/J or F1, CL/P was produced only in cases where the fetuses were genetically pure A/J. CL/P frequency was 7.46% in A/J fetuses developed in A/J mothers; it was 5.88% in F1 mothers with transplanted A/J ovaries. Isolated cleft palate (CP) and cleft lip with cleft palate (CLP) were found in A/J mothers. However, the frequency of CP was lower in F1 mothers than in A/J mothers. These results suggest that the occurrence of CLP depends more on the genetic constitution of the fetus than on maternal environmental factors, and the occurrence of CP was influenced by the mother's condition.