Search

Only limited information is available on agonist-dependent changes in the subcellular localization of vasopressin V1B receptors. Our radioligand binding study of membrane preparations and intact cells revealed that a large fraction of the V1B receptor is located in the cytoplasm in unstimulated CHO cells, which is in contrast to the plasma membrane localization of the V1A and V2 receptors. Moreover, when the affinity of radiolabeled arginine-vasopressin ([3H]AVP) was compared between membrane preparations and intact cells, the affinity of [3H]AVP to the cell surface V1B receptors, but not the V1A receptors, was significantly reduced. Although the number and affinity of cell surface V1B receptors decreased, they became extensively internalized upon binding with [3H]AVP. Approximately 87% of cell surface-bound [3H]AVP was internalized and became resistant to acid wash during incubation with 1 nM [3H]AVP. By contrast, less ligand (35%) was internalized in the cells expressing the V1A receptor. Extensive internalization of the V1B receptors was partially attenuated by inhibitors of cytoskeletal proteins, siRNA against β-arrestin 2, or the removal of sodium chloride from the extracellular buffer, indicating that this internalization involves clathrin-coated pits. Together, these results indicate that the mechanism that regulates the number and affinity of V1B receptors in the plasma membrane is markedly distinct from the corresponding mechanisms for the V1A and V2 receptors and plays a critical role under stress conditions, when vasopressin release is augmented.

Background: Animal studies on the effects of vitamin E on bone health have yielded conflicting and inconclusive results, and to our knowledge, no studies have addressed the effect of vitamin E on bone in animals consuming a high-fat diet (HFD).Objective: This study aimed to evaluate the effect of excessive vitamin E on bone metabolism in normal male mice and ovariectomized female mice fed a normal diet (ND) or HFD.Methods: In the first 2 experiments, 7-wk-old male mice were fed an ND (16% energy from fat) containing 75 (control), 0 (vitamin E-free), or 1000 (high vitamin E) mg vitamin E/kg (experiment 1) or an HFD (46% energy from fat) containing 0, 200, 500, or 1000 mg vitamin E/kg (experiment 2) for 18 wk. In the third experiment, 7-wk-old sham-operated or ovariectomized female mice were fed the ND (75 mg vitamin E/kg) or HFD containing 0 or 1000 mg vitamin E/kg for 8 wk. At the end of the feeding period, blood and femurs were collected to measure bone turnover markers and analyze histology and microcomputed tomography.Results: In experiments 1 and 2, vitamin E intake had no effect on plasma alkaline phosphatase (ALP), tartrate-resistant acid phosphatase (TRAP) activity, or bone formation, resorption, or volume in femurs in mice fed the ND or HFDs. In experiment 3, bone volume was significantly reduced (85%) in ovariectomized mice compared with that in sham-operated mice (P < 0.05), but it did not differ among mice fed the 3 diets. Plasma ALP and TRAP activities and bone formation and resorption in femur were similar among ovariectomized mice fed the HFD containing 0 or 1000 mg vitamin E/kg.Conclusions: The results suggest that excess vitamin E intake does not cause bone loss in normal male mice or in ovariectomized or sham-operated female mice, regardless of dietary fat content.

Theoretical simulations suggest that spike rate is regulated by varying both membrane potential and its fluctuation. We investigated whether membrane potential fluctuation functionally changes in motor cortex and striatum neurons during discrete forelimb movements and pauses, or at rest, using whole-cell recording in task-performing rats. Membrane potential fluctuation was diminished by task performance, but maintained overall in the alpha/beta and gamma bands during forelimb movements and pauses. By contrast, membrane potential itself was correlated with spike rate in task-related neurons. Thus, membrane potential, but not its fluctuation, is a critical determinant of execution and pausing of discrete movements.

Mass care feeding for disaster evacuees is an important component of public health preparedness. If universities that offer a training course for registered dietitians could provide food assistance to the evacuated people in their campus, it could contribute to maintain their health. Many universities are expected to become a base of support activities for people affected by disaster. This study aimed to reveal disaster preparedness in a university that offers a training course for registered dietitians, from the aspect of provision of mass care feeding. As Japan has 124 universities that offer such training courses, this case study could serve as a useful reference for them and contribute to the improvement of health of the affected people. A group interview was conducted in University A in 2012. The participants included two faculty members in the course, a vice president, a staff member, and a faculty member in charge of disaster preparedness and response. Stockpiled foods were limited to dry bread and pre-processed rice. No alternative heat sources were stored. It was concluded that to provide nutrients other than carbohydrate, hot meals should be served for the evacuees. Additionally, it would be difficult to provide meal service when the essential utilities such as gas and electricity are disrupted.

Lipid droplets (LDs) are independent organelles in adipocytes that are composed of a lipid ester core surrounded by a phospholipid monolayer. The fatty acid composition of the phospholipid monolayer should determine the metabolism and dynamics of LDs. In this study, we examined the fatty acid composition of phospholipid monolayer in LDs during the differentiation of 3T3-L1 adipocytes. The levels of saturated fatty acids (SFAs), such as 16:0 and 18:0, in phosphatidylcholine (PC) and phosphatidylethanolamine (PE) of LDs decreased during differentiation. In contrast, the levels of monounsaturated fatty acids (MUFAs) such as 16:1n-7 and 18:1n-9 in PC and PE of LDs and the level of polyunsaturated fatty acids (PUFAs) such as 20:3n-6, 20:4n-6 and 22:6n-3 in PE of LDs increased during differentiation. These results suggest that the phospholipid monolayer in mature LDs is more fluid than that in nascent LDs. The fatty acid compositions of the LD monolayer were different from those of the microsome bilayer in the early stage of differentiation, but similar to those of the microsome bilayer in the late stage of differentiation. These data provide evidence that biophysical properties of the phospholipid monolayer in LDs change during adipocyte differentiation.

The tocolytic agent ritodrine acts on the β2-adrenoceptor and is an effective treatment option for preterm labor. However, several adverse effects of ritodrine therapy, including liver damage, have been noted. To elucidate the underlying mechanisms of ritodrine-induced adverse effects, development of sensitive biomarkers of these adverse events is necessary. Here, we report the development and analysis of an animal model of ritodrine-induced liver damage. Female mice received daily ritodrine injections for 2 weeks; liver samples were then collected and subjected to DNA microarray analysis. Ritodrine significantly altered the expression of genes related to steroid and lipid metabolism, as well as the metabolism of ritodrine itself. Importantly, expression of the acute-phase reactant serum amyloid A (SAA) significantly increased after ritodrine injection, with values indicating the largest fold-change. This large increase in blood SAA levels serves as a more sensitive biomarker than conventional liver enzymes, such as aspartate aminotransferase and alanine aminotransferase. The increase in SAA expression is specific to ritodrine-induced liver damage, because SAA expression was not induced by other hepatotoxic drugs such as acetaminophen, valproic acid, or metformin. Our in vitro studies showed that cyclic adenosine 3',5'-monophosphate (cAMP) accumulation was not a primary cause of the ritodrine-induced SAA increase. Instead, SAA expression was enhanced by indirect phosphorylation of the signal transducer and activator of transcription-3 (STAT3) mediated by interleukin-6. Therefore, our study provides a method for sensitive and early detection of hepatic injury, and may thus help preclude serious liver damage due to ritodrine use in preterm labor.

Fatty acid (FA) compositions in tissues are related to metabolic disorders, and consequently the appropriate management of underlying FA compositions in tissues is considered to be important. However, the relationship among the serum lipid profiles, the FA composition of the red blood cell (RBC) membranes and genetic variations in the fatty acid desaturase (FADS) genes in Japanese men is unclear. In this study, the subjects recruited were 137 Japanese men, 40 to 60 y old, who had a regular health checkup. Their serum lipid profile and the relative FA composition of the RBC membranes were measured. They were genotyped for the single nucleotide polymorphisms (SNPs) rs174553, rs174546, rs99780 and rs174583 in FADS gene. Multiple regression analysis was conducted to detect the relationship among hyperlipidemia, the FA composition of the RBC and the FADS genotypes. As a result, the homozygous genotype for the minor alleles in rs174553, rs174546, rs99780 were found to be associated with lower low-density lipoprotein cholesterol (LDL-C) levels and a lower LDL-C/total-cholesterol ratio. The homozygous genotype for the minor alleles reduced the risk of high LDL-C level (R2=0.50, β=-0.20, p=0.009), whereas, the arachidonic acid (AA) levels in the carriers of the homozygous genotype for the minor alleles tended to be lower compared with the carriers of the major alleles. However, no significant differences were observed in any FA level among the three genotypes for four SNPs. These results indicate that the appropriate management of serum LDL-C levels depending on genetic predisposition in FADS genotypes should be encouraged.

Background The amount of urinary glycoprotein lipocalin 2 (LCN2) has been known to increase after kidney injury because of failed reabsorption by the proximal tubules or direct secretion from injured tissues. However, the relationship between urinary tract obstruction and the isoform diversity of LCN2 has not been examined. Methods The urinary levels of LCN2 isoforms were examined in male mice after an intraperitoneal injection of lipopolysaccharide (LPS) or in a mouse model of unilateral ureter obstruction (UUO). The LCN2 levels in sera, bladder urine, renal pelvic urine, and tissue samples were also analyzed. Endo- and exoglycosidases were used to investigate the different N-glycan patterns of LCN2. Results Two isoforms of urinary LCN2 with different molecular weights were identified in an immunoblotting analysis, and the levels of both isoforms were increased 6 h after LPS administration. The primary LCN2 isoform was the lower molecular weight 22-kDa isoform, which was detected in the serum, urine, liver and kidney. In contrast, the 24-kDa LCN2 isoform was detected only in urine. In the UUO experiments, the levels of the 24-kDa LCN2 were increased in the bladder urine but not in the urine accumulated in the renal pelvis due to UUO. The 22-kDa LCN2 was identified in the renal pelvic urine from UUO mice. The peptide-N glycosidase F digestion of the two urinary LCN2 isoforms generated a single protein. Moreover, the two urinary LCN2 proteins were sensitive to neuraminidase and resistant to endoglycosidase H (Endo H). The LCN2 in the serum, lung and kidney was resistant to Endo H, as observed in urine, whereas the LCN2 in the liver and the ureter were degraded by this enzyme. Conclusions These results suggest that the difference in the molecular weights of the LCN2 proteins was due to their N-glycan structure. The high molecular weight LCN2 in urine could be detected after the inflammatory response to LPS and UUO. Furthermore, the sensitivity to Endo H identified the presence of two types of carbohydrate moieties, depending on the tissue in which the LCN2 was produced. These findings are useful for widening the clinical applicability of urinary LCN2 analyses.

This is a study of 4 patients implemented to Advance Care Planning (ACP) reflecting on the health care professionals' role and the outcomes. ACP has been defined as a process of formal decision making that aims to help patients establish their decision about future care that take effect when they lose capacity. For about two years, we tried to engage all patients who were referred to our palliative care team and their families to ACP since their first consultation. We informed their conditions at that time, how their health might change and how treatment might impact on their life goals. We also attempted to help patients' decision making and then fulfill their wishes in cooperation with patients' families and healthcare professionals. We learned three important elements: understanding patients' values and wishes, explaining prediction of the clinical course of the patients and establishing a collaborative healthcare team in order to fulfill the patients' hopes. ACP improved quality of life (QOL) not only for the patients involved, but also for the family members. ACP can play a crucial role in ensuring that patients receive the care they want throughout various stages of their lives.

Adverse events in tocolytic therapy with β2-adrenergic agents compromise cardiovascular and non-cardiovascular functions, including blood glucose regulation and liver function. Here, we have examined the effects of the β2 agonist ritodrine on glucose metabolism and liver injury in mice. Under fasting conditions, ritodrine significantly increased serum insulin levels and decreased glucose concentrations. This contrasts with the β2 agonist-induced hyperglycemia observed in previous studies on humans and other animals. After 14 days of ritodrine treatment, the mice showed a decrease in the total mass of epididymal fat pads, whereas their body weights increased significantly. Chronic ritodrine treatment attenuated the glucose-lowering effect observed during acute administration. Ritodrine also significantly increased serum levels of liver enzymes, which returned to control levels after 14 days of treatment. Thus, ritodrine responsiveness changes between acute and chronic treatment, indicating that close monitoring of blood glucose and serum liver enzymes is necessary in patients with reduced glucose tolerance. The findings reported here of glucose homeostasis in mice provide a unique opportunity to understand refractoriness of β2-adrenoceptor signaling in response to β2 agonists during the course of treatment.

The components bringing the effects of fish oil on glucose and lipid metabolism are unclear. We used hydrogenated fish oil, which has saturated fatty acids with the same carbon chain lengths as the unsaturated fatty acids in fish oil, to clarify the functions of these unsaturated fatty acids on the improvements in lipid and glucose metabolism in mice. Mice divided into 3 groups were fed different diets: fish oil diet (FO), hydrogenated fish oil diet (HFO), and soybean oil diet (SBO) as a control. Body weight gain and white adipose tissue weight in the HFO and FO groups were significantly decreased compared with those in the SBO group. However, in the HFO group, the triglyceride (TG) levels in plasma were significantly decreased, while the lipids levels in the liver were remarkably increased compared with those in the FO group. Regarding the fatty acid composition in the liver and white adipose tissue in the HFO group, in parallel with the up-regulation of stearoyl-CoA desaturase 1 mRNA, relative amounts of C16 : 1 and C18 : 1 were significantly increased. By contrast, blood glucose levels in the oral glucose tolerance test had not deteriorated in the HFO group. Our results indicate that unsaturated fatty acids in the FO diet decrease lipid levels in the liver and maintain the balance of lipid levels in plasma, liver and white adipose tissue; in addition, in the HFO group, C16 : 1 and C18 : 1 synthesized in the liver and white adipose tissue may improve glucose tolerance and lipid metabolism.

cis- and trans-Cycloheptane-1,2-diyl-fused crown thioethers ([12]ansS4), 2,3-cis- and 2,3-trans-cycloheptano-1,4,7,10-tetrathiacyclododecanes (cis-2 and (±)-trans-2), were synthesized from newly prepared cis- and trans-cycloheptane-1,2-ditiols, respectively. X-ray diffraction analyses on cis-2 and (–)-trans-2, which was obtained by optical resolution of (±)-trans-2 with a chiral column, showed that in cis-2 the S-C-C-S part fused with the cis-cycloheptane-1,2-diyl adopted a gauche orientation and that in (–)-trans-2 all S-C-C-S parts took anti-conformations. A competitive complexation experiment of cis-2 and (±)-trans-2 with AgOTf revealed that cis-2 was more favorable than (±)-trans-2 for the complexation. The structure of [Ag(cis-2)]NO3 was analyzed by X-ray crystallography. © 2011 Wiley Periodicals, Inc. Heteroatom Chem 22:388–396, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.20695

日本では，平成17年から栄養教諭制度が始まっている。これは世界的にみて新しい制度であるため，栄養教育実習に関してどのような課題があるか検討した報告はない。本研究では，栄養教諭免許保持者の特徴を把握し，また，非保持者と比較して，栄養教育実習を受け入れるにあたっての課題に違いがあるかどうか検討した。東京都の栄養教諭および学校栄養職員1,627名を対象に，質問紙調査を行った。その結果，栄養教諭免許保持者の約半数は50歳代であり，学校での栄養士職年数は30年以上であった。栄養教育実習を受け入れるにあたっての課題については，いくつかの課題（例えば「実習生を引き受けるために十分なスキルが自分に足りない」）に対して，栄養教諭免許保持者は「あてはまらない」「あまりあてはまらない」と答える割合が高かった。また，「今後，栄養教育実習の依頼があった場合引き受けるか」という質問に対しては，栄養教諭免許非保持者と比較して，保持者では，「引き受けると思う」と答える割合が高かった（p＜0.001）。本研究により，栄養教諭免許保持者の特徴と栄養教育実習を受け入れるにあたっての課題が把握できた。今後は，課題の多い人の特徴を把握し，課題を軽減させる方策について検討する必要があるだろう。（オンラインのみ掲載）

Food intake is regulated by various factors such as neuropeptide Y. Neuropeptide Y potently induces an increase in food intake, and simultaneously stimulates arginine-vasopressin (AVP) secretion in the brain. Recently, we reported that V(1A) vasopressin receptor-deficient (V(1A)R(-/-)) mice exhibited altered daily food intake accompanied with hyperglycemia and hyperleptinemia. Here, we further study the involvement of the AVP/V(1A) receptor in the appetite regulation of neuropeptide Y with V(1A)R(-/-) mice and antagonists for the AVP receptor. The intra-cerebral-ventricle administration of neuropeptide Y induced greater food consumption in V(1A)R(-/-) mice than wild-type (WT) mice, whereas an anorexigenic effect of leptin was not different between the two groups. This finding suggests that the orexigenic effect of neuropeptide Y was enhanced in V(1A)R(-/-) mice, leading to the increased food intake in response to the neuropeptide Y stimulation. In addition, the neuropeptide Y-induced orexigenic effect was enhanced by co-administration of OPC-21268, an antagonist for the V(1A) vasopressin receptor, into the cerebral ventricle in WT mice, whereas the neuropeptide Y-induced orexigenic effect was not affected by co-administration of SSR-149415, an antagonist for the V(1B) vasopressin receptor. These results indicate that AVP could suppress the neuropeptide Y-induced orexigenic effect via the V(1A) vasopressin receptor, and that blockade or inhibition of the AVP/V(1A) receptor signal resulted in the enhanced neuropeptide Y-induced orexigenic effect. Thus, we show that the AVP/V(1A) receptor is involved in appetite regulation as an anorexigenic factor for the neuropeptide Y-induced orexigenic effect.

Alpha1-adrenergic receptors (alpha1-ARs) are classified into three subtypes: alpha1A-AR, alpha1B-AR, and alpha1D-AR. Triple disruption of alpha1A-AR, alpha1B-AR, and alpha1D-AR genes results in hypotension and produces no contractile response of the thoracic aorta to noradrenalin. Presently, we characterized vascular contractility against other vasoconstrictors, such as potassium, prostaglandin F2alpha (PGF(2alpha)) and 5-hydroxytryptamine (5-HT), in alpha1A-AR, alpha1B-AR, and alpha1D-AR triple knockout (alpha1-AR triple KO) mice.The contractile responses to the stimulation with vasoconstrictors were studied using isolated thoracic aorta.As a result, the phasic and tonic contraction induced by a high concentration of potassium (20 mM) was enhanced in the isolated thoracic aorta of alpha1-AR triple KO mice compared with that of wild-type (WT) mice. In addition, vascular responses to PGF(2alpha) and 5-HT were also enhanced in the isolated thoracic aorta of alpha1-AR triple KO mice compared with WT mice. Similar to in vitro findings with isolated thoracic aorta, in vivo pressor responses to PGF(2alpha) were enhanced in alpha1-AR triple KO mice. Real-time reverse transcription-polymerase chain reaction analysis and western blot analysis indicate that gene expression of the 5-hydroxytryptamine 2A (5-HT(2A)) receptor was up-regulated in the thoracic aorta of alpha1-AR triple KO mice while the prostaglandin F2alpha receptor (FP) was unchanged.These results suggest that loss of alpha1-ARs can lead to enhancement of vascular responsiveness to the vasoconstrictors and may imply that alpha1-ARs and the subsequent signaling regulate the vascular responsiveness to other stimulations such as depolarization, 5-HT and PGF(2alpha).

日本人の寿命が延びた一因に，戦後の食生活の変化があげられる．食物の選択肢が増え，動物性蛋白質の摂取が増加したことは寿命延長に大きく貢献しているが，動物性食品の摂取は動物性脂肪の摂取増加を意味する．日本人を対象とする疫学スタディからn-3系のEPAやDHAの摂取が，冠状動脈疾患や大うつ病などに有効であるという科学的な根拠も集まってきた．また近年，カロリー制限による寿命延長作用は，分子メカニズムが明らかにされ，注目されている．日本人の食と健康を考えるうえで重要な脂質摂取の話題について概説する．

To investigate the metabolism and distribution of docosapentaenoic acid (22:5n-6, DPA) in the liver and testis of growing rats, 22:5n-6 was administered to their dams. Newborn rats with a low hepatic arachidonic acid (20:4n-6, AA) level were generated by administrating a diet rich in docosahexaenoic acid (22:6n-3, DHA) but n-6 fatty acid (FA) free to pregnant dams. After parturition, 22:5n-6 or linoleic acid (18:2n-6, LA) was administered with a high level of 22:6n-3 to the dams until weaning. At weaning, the hepatic 20:4n-6 level was significantly highest in the DPA-DHA but not LA-DHA diet-fed animals. The hepatic delta-6 desaturase (D6D) mRNA abundance was significantly lower in both the LA-DHA and DPA-DHA diet-fed animals, connoted with the 20:4n-6 content recovered by 22:5n-6 that did not involve D6D and supporting the occurrence of retroconversion in the liver of the growing rats. The low D6D level in the 3-week-old testis was not in proportion to the elevated 22:5n-6 level, implying that early testicular 22:5n-6 accumulation might require supply from the circulation system.

The hippocampus is a remarkable neural structure that displays a variety of synchronous oscillations that may be physiological or pathophysiological, such as theta rhythms and epileptic seizures. Electrically induced seizure-like afterdischarges are an excellent system for elucidating the network mechanisms underlying neuronal synchronization and rhythm generation of epileptic synchronous oscillations in extremely hyperactive hippocampal networks. In this Update Article, we review key findings of studies on these electrically induced seizure-like afterdischarges in vitro. During these afterdischarges, GABAergic responses become transiently depolarizing and even excitatory as chloride rapidly accumulates postsynaptically in pyramidal cells. Glutamate and potassium enhance this transient GABAergic excitation. Neuronal synchronization of afterdischarge is achieved by GABAergic and glutamatergic excitation of pyramidal cells and interneurons localized in the stratum pyramidale and stratum oriens. Rhythm generation in seizure-like synchronous oscillations is not yet understood but is the subject of intensive study.

[Arg8]-vasopressin (Avp), a nonapeptide hormone, is known to regulate blood pressure, water balance, and a variety of behaviors such as anxiety, aggression, and bonding. Although some evidence that Avp modifies ethanol consumption and some of the effects of ethanol on behavior have been reported, the role of Avp in alcohol consumption and preference is poorly understood. The Avp1a receptor (Avpr1a) is ubiquitously expressed in the central nervous system. To determine the role of Avp signaling on the behavioral effects of alcohol, we examined voluntary ethanol consumption in mice with targeted disruptions of the Avpr1a knockout (Avpr1a KO) gene. Avpr1a KO mice displayed both increased ethanol consumption and preference compared with wild-type (WT) mice. Enhanced ethanol consumption was dramatically and reversibly reduced by treatment with N-methyl-d-aspartic acid antagonists. Basal glutamate release was elevated around the striatum in Avpr1a KO mice. Elevation of extracellular glutamate was also produced in WT mice by local application of an Avpr1a antagonist though a dialysis probe, and this elevation was quickly reversed by stopping the perfusion. These results suggest that Avp can inhibit the release of glutamate from the presynaptic terminal via the Avp1a receptor and that elevation of glutamate levels owing to loss of the inhibitory effect via Avp-Avpr1a signaling may play an important role in the preference for ethanol.

Resveratrol, a polyphenolic phytoalexin, has free-radical scavenging activity and we found that it induces chromosomal aberrations, micronuclei, and sister chromatid exchanges in vitro. We synthesized its analogue 4-hydroxy-trans-stilbene (4-OH) and found that it has the same in vitro clastogenic activities as resveratrol, suggesting that the 4′ hydroxy group of resveratrol is responsible for the effect. We fed resveratrol and 4-OH to young adult ICR mice at 0, 0.2, 2, or 20 ppm in their standard powder diet for 6 months and investigated the antioxidative effects. Half of each group was given 3000 ppm potassium bromate (KBrO3) in water for the last week to cause oxidative damage. Body weight gain tended to increase in males at 0.2 ppm resveratrol or 4-OH, and in females at 2 ppm 4-OH. Micronucleus (MN) analysis in bone marrow erythrocytes showed that the KBrO3 tendency to induce MN was not prevented by the dietary resveratrol or 4-OH, which themselves did not induce MN under the present conditions. In this pilot study, resveratrol and 4-OH showed no obvious effect, either beneficial or adverse, at doses that are feasible in daily life for humans.

We found that prostaglandin (PG) D(2), the most abundant PG in the central nervous system, stimulates food intake after intracerebroventricular administration in mice. The orexigenic effect of PGD(2) was mimicked by a selective agonist for the DP(1) receptor among two receptor subtypes for PGD(2), and abolished by its antagonist. Central administration of an antagonist or antisense oligodeoxynucleotide for the DP(1) receptor remarkably decreased food intake, body weight and fat mass. Hypothalamic mRNA levels of lipocalin-type PGD synthase were up-regulated after fasting. The orexigenic activity of PGD(2) was also abolished by an antagonist for neuropeptide Y (NPY) Y(1) receptor. Taken together, PGD(2) may stimulate food intake through central DP(1) receptor coupled to the NPY system.

To investigate the new physiological functions of oolong tea, the effects on melanogenesis were studied. An oolong tea extract inhibited melanogenesis without affecting cell growth in B16 mouse melanoma cells. However, the oolong tea extract hardly showed any inhibitory effect on mushroom tyrosinase in a cell-free system. The effects of an oolong tea extract on the intracellular tyrosinase level in B16 cells were therefore studied. All the levels of activity, protein and mRNA were decreased in the oolong tea extract-treated cells. We also investigated the inhibitory effects of oolong tea on the pigmentation induced by ultraviolet B (UVB) by using brownish guinea pigs in vivo. The number of 3,4-dihydroxyphenylalanine (DOPA)-positive melanocytes increased by UVB was repressed by an oral administration of oolong tea. These results imply that oolong tea might be effective in whitening and that its inhibitory effect on melanogenesis was involved in the decrease of intracellular tyrosinase at the mRNA level.

We examined aldosterone release in response to stimulation with arginine–vasopressin (AVP) using adrenal gland cells. AVP caused a significant increase in aldosterone release from the dispersed adrenal gland cells of wild-type mice (V 1A R +/+ ) at concentrations from 0.1 μM to 1 μM. In contrast, AVP-induced aldosterone release was impaired in adrenal gland cells from mice lacking the vasopressin V 1A receptor (V 1A R −/− ), while adrenocorticotropic hormone (ACTH)-induced aldosterone release in V 1A R −/− mice was not significantly different from that in V 1A R +/+ mice. In addition, a vasopressin V 1A receptor-selective antagonist 1-[1-[4-(3-acetylaminopropoxy)benzoyl]-4-piperidyl]-3,4-dihydro-2(1 H )-quinolinone (OPC-21268) potently inhibited AVP-induced aldosterone release. Thus, our study clearly demonstrates that AVP-induced aldosterone release from adrenal gland cells is mediated via the vasopressin V 1A receptor in mice.

An analysis of arginine-vasopressin (AVP) V1a receptor-deficient (V1aR−/−) mice revealed that glucose homeostasis and lipid metabolism were altered in the mutant mice. Here, we used V1aR−/− mice to investigate whether the deficiency of the V1a receptor, which led to altered insulin sensitivity, affected protein metabolism. The serum 3-methylhistidine levels were increased in V1aR−/− mice under feeding conditions, indicating that proteolysis was enhanced in muscle tissue from V1aR−/− mice. Furthermore, serum amino acid profiling revealed that the amino acid levels, including glycogenic and branched-chain amino acids, were reduced in V1aR−/− mice. In addition, an alanine-loading test showed that gluconeogenesis was enhanced in V1aR−/− mice. Blood ammonia, which is a by-product of amino acid catabolism, was two times higher in V1aR−/− mice without hepatopathy under the feeding and fasting conditions than in wild-type mice. Amino acid profiling also revealed that the amino acid pattern was not typical of a urea-cycle enzymatic disorder. An ammonia tolerance test and an indocyanine green elimination test showed that V1aR−/− mice had lower ammonia clearance due to a decreased intrahepatic circulating blood volume. Metabolic acidosis, including lactic- and keto-acidosis, was not observed in V1aR−/− mice. These results provide evidence that proteolysis promotes the production of glucose in the muscles of V1aR−/− mice and that hyperammonaemia is caused by promoted protein catabolism and reduced intrahepatic blood volume. Thus, our study with V1aR−/− mice indicates that AVP plays a physiological role via the V1a receptor in regulating both protein catabolism and glucose homeostasis.

application/pdf, text/plain, 学術雑誌論文, Human mesenchymal stem cells (hMSCs) are able to both self-replicate and differentiate into a variety of cell types. Fibroblast growth factor-2 (FGF-2) stimulates the growth of hMSCs in vitro, but its mechanisms have not been clarified yet. In this study, we investigated whether cellular senescence was involved in the stimulation of hMSCs growth by FGF-2 and the expression levels of transforming growth factor-β1 and -β2 (TGF-βs). Because hMSCs were induced cellular senescence due to long-term culture, FGF-2 decreased the percentage of senescent cells and suppressed G1 cell growth arrest through the suppression of p21(Cip1), p53, and p16(INK4a) mRNA expression levels. Furthermore, the levels of TGF-βs mRNA expression in hMSCs were increased by long-term culture, but FGF-2 suppressed the increase of TGF-β2 mRNA expression due to long-term culture. These results suggest that FGF-2 suppresses the hMSCs cellular senescence dependent on the length of culture through down-regulation of TGF-β2 expression.

Carbamazepine (CBZ) is one of the most commonly prescribed antiepileptic drugs (AEDs). However, a higher rate of congenital anomalies has been found in infants of mothers treated with CBZ during early pregnancy. Here, we characterize the effects of CBZ using a mouse ES cell differentiation system. The analysis of tissue-specific gene markers showed that CBZ induced early endodermal and mesodermal differentiation but inhibited differentiation of later stages. CBZ also induced ectodermal development, and there was evidence of neural differentiation as ES cells with an immature neuronal phenotype were observed. In contrast, valproic acid (VPA), another anticonvulsant drug, was previously shown to be able to induce ES cells to differentiate into neurons with a mature appearance. CBZ was less cytotoxic to ES cells than VPA. The in vitro ES cell assay system has the potential to provide a rapid and accurate approach for estimating the in vivo embryotoxicity of therapeutic drugs.

It has recently been shown that electrical stimulation in normal extracellular fluid induces seizure-like afterdischarge activity that is always preceded by GABA-dependent slow depolarization. These afterdischarge responses are synchronous among mature hippocampal neurons and driven by excitatory GABAergic input. However, the differences in the mechanisms whereby the GABAergic signals in pyramidal cells and interneurons are transiently converted from hyperpolarizing to depolarizing (and even excitatory) have remained unclear. To clarify the network mechanisms underlying this rapid GABA conversion that induces afterdischarges, we examined the temporal changes in GABAergic responses in pyramidal cells and/or interneurons of the rat hippocampal CA1 area in vitro. The extents of slow depolarization and GABA conversion were much larger in the pyramidal cell group than in any group of interneurons. Besides GABA(A) receptor activation, neuronal excitation by ionotropic glutamate receptors enhanced GABA conversion in the pyramidal cells and consequent induction of afterdischarge. The slow depolarization was confirmed to consist of two distinct phases; an early phase that depended primarily on GABA(A)-mediated postsynaptic Cl- accumulation, and a late phase that depended on extracellular K+ accumulation, both of which were enhanced by glutamatergic neuron excitation. Moreover, extracellular K+ accumulation augmented each oscillatory response of the afterdischarge, probably by further Cl- accumulation through K+-coupled Cl- transporters. Our findings suggest that the GABA reversal potential may be elevated above their spike threshold predominantly in the pyramidal cells by biphasic Cl- intrusion during the slow depolarization in GABA- and glutamate-dependent fashion, leading to the initiation of seizure-like epileptiform activity.

[Trp5]-oryzatensin(5-9) (WPLPR), an agonist peptide for complement C3a receptor, has been designed based on the C-terminal region of ileum-contracting peptide oryzatensin derived from rice protein. We previously reported that WPLPR has anti-analgesic and anti-amnesic activities after central or oral administration. In this study, we found a novel function of WPLPR on food intake. WPLPR suppressed food intake after intracerebroventricular or intraperitoneal (i.p.) administration at a dose of 3-30 nmol/mouse or 30-300 mg/kg, respectively, in fasted mice. Orally administered WPLPR at a dose of 300 mg/kg also decreased food intake. WPLPR decreased gastric emptying after i.p. injection at a dose of 300 mg/kg. The anorexigenic activity of WPLPR was blocked by cyclooxygenase inhibitor or antagonist for prostaglandin (PG) E receptor EP4 subtype. These results suggest that WPLPR decreases food intake through PGE2 production followed by EP4 receptor activation.

[Arg8]-vasopressin (AVP) and oxytocin (OT) are neurohypophysial hormones which exert various actions, including the control of blood glucose, in some peripheral tissues. To investigate the type of receptors involved in AVP- and OT-induced glucagon secretion, we investigated the effect of these peptides on glucagon secretion in islets of wild-type (V1bR+/+) and vasopressin V1b receptor knockout (V1bR−/−) mice. AVP-induced glucagon secretion was significantly inhibited by the selective V1b receptor antagonist, SSR149415 (30%), and OT-induced glucagon secretion by the specific OT receptor antagonist, d(CH2)5[Tyr(Me)2, Thr4, Tyr-NH29]OVT (CL-14-26) (45%), in islets of V1bR+/+mice. AVP- and OT-induced glucagon secretions were not by the antagonist of each, but co-incubation with both 10−6 M SSR149415 and 10−6 M CL-14-26 further inhibited AVP- and OT-induced glucagon secretions in islets of V1bR+/+ mice (57 and 69% of the stimulation values respectively). In addition, both AVP and OT stimulated glucagon secretion with the same efficacy in V1bR−/− mice as in V1bR+/+ mice. AVP- and OT-induced glucagon secretion in V1bR−/− mice was significantly inhibited by CL-14-26. These results demonstrate that V1b receptors can mediate OT-induced glucagon secretion and OT receptors can mediate AVP-induced glucagon secretion in islets from V1bR+/+mice in the presence of a heterologous antagonist, while AVP and OT can stimulate glucagon secretion through the OT receptors in V1bR−/−mice, suggesting that the other receptor can compensate when one receptor is absent.

An R120G missense mutation in alpha-B-crystallin (CryAB), a small heat-shock protein (HSP), causes a desmin-related cardiomyopathy (DRM) that is characterized by the formation of aggregates containing CryAB and desmin. The mutant CryAB protein leads to the formation of inclusion bodies, which contain amyloid oligomer intermediates (amyloid oligomer) in the cardiomyocytes. To further address the underlying mechanism(s) of amyloid oligomer formation in DRM linked to the CryAB R120G, a recombinant CryAB R120G protein was generated. The purified CryAB R120G protein can form a toxic amyloid oligomer, whereas little immunoreactivity was observed in the wild-type CryAB protein. A native PAGE showed that the oligomerized form was present in the CryAB R120G protein, whereas only a high molecular mass was detected in the wildtype CryAB. The oligomerized CryAB R120G of around 240-480 kDa showed strong positive immunoreactivity against an anti-oligomer antibody. The CryAB R120G amyloid oligomer was unstable and easily lost its conformation by beta-mercaptoethanol and SDS. Recombinant HSP25 or HSP22 proteins can directly interrupt oligomer formation by the CryAB R120G protein, whereas the amyloid oligomer is still present in the mixture of the wild-type CryAB and CryAB R120G proteins. This interruption by HSP25 and HSP22 was confirmed in a cardiomyocyte-based study using an adenoviral transfection system. Blockade of amyloid oligomer formation by HSP25 and HSP22 recovered the ubiquitin proteosomal activity and cellular viability. Blockade of oligomer formation by small HSP may be a new therapeutic strategy for treating DRM as well as other types of amyloid-based degenerative diseases.

Prostaglandin (PG) E 2 , a bioactive lipid produced in the brains of various mammals, decreases food intake after central administration. We examined which of four distinct subtypes of PGE 2 receptors (EP 1 –EP 4 ) mediated the anorexigenic action of PGE 2 using highly selective ligands. PGE 2 at a dose of 0.1–10 nmol/mouse decreased food intake after intracerebroventricular (i.c.v.) administration in a dose-dependent manner in fasted mice. A centrally administered EP 4 agonist, ONO-AE1-329 at a dose of 1–10 nmol/mouse mimicked the anorexigenic action by PGE 2 . The anorexigenic action of PGE 2 or EP 4 agonist was ameliorated by EP 4 antagonist ONO-AE3-208 at a dose of 10 nmol/mouse. Thus, activation of PGE 2 –EP 4 signaling in the central nervous system suppresses food intake. The EP 4 agonist at a dose of 10 nmol/mouse delayed gastric emptying and elevated blood glucose.

It is known that GABA is a major inhibitory neurotransmitter in mature mammalian brains, but the effect of this substance is sometimes converted into depolarizing or even excitatory when the postsynaptic Cl– concentration becomes high. Recently we have shown that seizurelike afterdischarge induced by tetanic stimulation in normal extracellular fluid (posttetanic afterdischarge) is mediated through GABAergic excitation in mature hippocampal CA1 pyramidal cells. In this study, we examined the possible contribution of similar depolarizing/excitatory GABAergic input to the CA1 pyramidal cells to the seizurelike afterdischarge induced in a low extracellular Mg2+ condition, another experimental model of epileptic seizure activity (low-Mg2+ afterdischarge). Perfusion of the GABAA antagonist bicuculline abolished the low-Mg2+ afterdischarge, but not the interictal-like activity, in most cases. Each oscillatory response during the low-Mg2+ afterdischarge was dependent on Cl– conductance and contained an F–-insensitive depolarizing component in the pyramidal cells, thus indicating that the afterdischarge response may be mediated through both GABAergic and nonGABAergic transmissions. In addition, local GABA application to the recorded cells revealed that GABA responses were indeed depolarizing during the low-Mg2+ afterdischarge. Furthermore, the GABAergic interneurons located in the strata pyramidale and oriens fired in oscillatory cycles more actively than those in other layers of the CA1 region. These results suggest that the depolarizing GABAergic input may facilitate oscillatory synchronization among the hippocampal CA1 pyramidal cells during the low-Mg2+ afterdischarge in a manner similar to the expression of the posttetanic afterdischarge.

A group of synthetic substance P (SP) antagonists, such as [Arg(6),D-Trp(7,9),N(Me)Phe(8)]-substance P(6-11) and [D-Arg(1),D-Phe(5),D-Trp(7,9),Leu(11)]-substance P, bind to a range of distinct G-protein-coupled receptor (GPCR) family members, including V1a vasopressin receptors, and they competitively inhibit agonist binding. This extended accessibility enabled us to identify a GPCR subset with a partially conserved binding site structure. By combining pharmacological data and amino acid sequence homology matrices, a pharmacological lineage of GPCRs that are sensitive to these two SP antagonists was constructed. We found that sensitivity to the SP antagonists was not limited to the Gq-protein-coupled V1a and V1b receptors; Gs-coupled V2 receptors and oxytocin receptors, which couple with both Gq and Gi, also demonstrated sensitivity. Unexpectedly, a dendrogram based on the amino acid sequences of 222 known GPCRs showed that a group of receptors sensitive to the SP antagonists are located in close proximity to vasopressin/oxytocin receptors. Gonadotropin-releasing peptide receptors, located near the vasopressin receptors in the dendrogram, were also sensitive to the SP analogs, whereas α1B adrenergic receptors, located more distantly from the vasopressin receptors, were not sensitive. Our finding suggests that pharmacological lineage analysis is useful in selecting subsets of candidate receptors that contain a conserved binding site for a ligand with broad-spectrum binding abilities. The knowledge that the binding site of the two broad-spectrum SP analogs partially overlaps with that of distinct peptide agonists is valuable for understanding the specificity/broadness of peptide ligands.

Strong tetanization induces synchronous membrane potential oscillations (seizure-like afterdischarge) in mature pyramidal cells of the hippocampal CA1 region. To investigate whether local networks in other brain regions can generate such an afterdischarge independently, we studied the inducibility of afterdischarge in individual ‘isolated slices’ of the rat hippocampal CA1 and CA3 regions, dentate gyrus (DG), entorhinal cortex (EC), and temporal cortex (TC) using intracellular and extracellular recordings. The strong tetanization constantly induced afterdischarges in the CA1 and CA3 pyramidal cells as well as in the EC and TC superficial principal cells. However, parameters of the afterdischarges, such as the frequency and duration of afterdischarges, varied among the regions. A mixture of N -methyl- d -aspartate (NMDA) and non-NMDA receptor antagonists or a GABA A receptor antagonist completely blocked the afterdischarges. Local GABA application during the afterdischarge elicited depolarization, rather than hyperpolarization. Moreover, reversal potentials of the afterdischarge were around −40 mV. In contrast, the tetanization resulted in occasional afterdischarge-like activities in DG slices, which were blocked by the non-NMDA or GABA A receptor antagonist. These findings suggest that the afterdischarges mediated through the excitatory GABAergic and glutamatergic transmissions might be common to, but be modulated differently by individual local networks in the hippocampus and cortex.

We have recently reported that excitatory GABAergic and glutamatergic mechanisms may be involved in the generation of seizure-like (ictal) rhythmic synchronization (afterdischarge), induced by a strong synaptic stimulation of the CA1 pyramidal cells in the mature rat hippocampus in vitro. To clarify the network mechanism of this neuronal synchronization, dual whole-cell patch-clamp recordings of the afterdischarge responses were performed simultaneously from a variety of interneurones and their neighbouring pyramidal cells in hippocampal CA1-isolated slice preparations. According to morphological and electrophysiological criteria, the recorded interneurones were then classified into distinct subtypes. The non-fast-spiking interneurones located in the strata lacunosum-moleculare and radiatum hardly discharged during the afterdischarge, whereas most of the fast-spiking and non-fast-spiking interneurones in the strata oriens and pyramidale, including the basket, chandelier and bistratified cells, exhibited prominent firings that were precisely synchronous with oscillatory responses in the pyramidal cells. Field potential recordings showed that excitatory synaptic transmissions might take place primarily in the strata oriens and pyramidale during the afterdischarge. Restricted lesions in the strata oriens and pyramidale, but not in the other layers, resulted in the complete desynchronization of afterdischarge activity, and also, local application of glutamate receptor antagonists to these layers blocked the expression of afterdischarge. The present findings indicate that the neuronal synchronization of epileptic afterdischarge may be accomplished in a ‘positive feedback circuit’ formed by the excitatory GABAergic interneurones and the glutamatergic pyramidal cells within the strata oriens and/or pyramidale of the hippocampal CA1 region.

It is known that GABA, a major inhibitory transmitter in the CNS, acts as an excitatory (or depolarizing) transmitter transiently after intense GABAA receptor activation in adult brains. The depolarizing effect is considered to be dependent on two GABAA receptor-permeable anions, chloride (Cl–) and bicarbonate (HCO3–). However, little is known about their spatial and temporal profiles during the GABAergic depolarization in postsynaptic neurons. In the present study, we show that the amplitude of synaptically induced depolarizing response was correlated with intracellular Cl– accumulation in the soma of mature hippocampal CA1 pyramidal cells, by using whole cell patch-clamp recording and Cl– imaging technique with a Cl– indicator 6-methoxy- N-ethylquinolinium iodide (MEQ). The synaptically activated Cl– accumulation was mediated dominantly through GABAA receptors. Basket cells, a subclass of fast-spiking interneurons innervating the somatic portion of the pyramidal cells, actually fired at high frequency during the Cl– accumulation accompanying the depolarizing responses. These results suggest synaptically activated GABAA-mediated Cl– accumulation may play a critical role in generation of an excitatory GABAergic response in the mature pyramidal cells receiving intense synaptic inputs. This may be the first demonstration of microscopic visualization of intracellular Cl– accumulation during synaptic activation.

The effect of neuronal cells on the functional properties of intestinal epithelial cells was examined by using an in vitro coculture system. Two cell lines, Caco-2 and PC12, were respectively used as intestinal epithelial and enteric neuronal cell models. Coculture of differentiated Caco-2 cells with PC12 caused a significant decrease in the transepithelial electrical resistance (TER) value of the Caco-2 monolayer. The permeability to lucifer yellow (LY) was also significantly increased, suggesting that the tight junction (TJ) of the Caco-2 monolayers was modulated by coculturing with PC12. To identify the TJ-modulating factor presumably secreted from PC12, the effects of the major neurotransmitters on the TER value and LY transport were examined, but no influence was apparent. The TJ-modulating effect of PC12 was prevented by exposing PC12 to cycloheximide, suggesting that new protein synthesis in PC12 was necessary for this regulation.

Low concentration of Ni2+, a T- and R-type voltage-dependent calcium channel (VDCC) blocker, is known to inhibit the induction of long-term potentiation (LTP) in the hippocampal CA1 pyramidal cells. These VDCCs are distributed more abundantly at the distal area of the apical dendrite than at the proximal dendritic area or soma. Therefore we investigated the relationship between the Ni2+-sensitivity of LTP induction and the synaptic location along the apical dendrite. Field potential recordings revealed that 25 μM Ni2+ hardly influenced LTP at the proximal dendritic area (50 μm distant from the somata). In contrast, the same concentration of Ni2+ inhibited the LTP induction mildly at the middle dendritic area (150 μm) and strongly at the distal dendritic area (250 μm). Ni2+ did not significantly affect either the synaptic transmission at the distal dendrite or the burst-firing ability at the soma. However, synaptically evoked population spikes recorded near the somata were slightly reduced by Ni2+ application, probably owing to occlusion of dendritic excitatory postsynaptic potential (EPSP) amplification. Even when the stimulating intensity was strengthened sufficiently to overcome such a reduction in spike generation during LTP induction, the magnitude of distal LTP was not significantly recovered from the Ni2+-dependent inhibition. These results suggest that Ni2+ may inhibit the induction of distal LTP directly by blocking calcium influx through T- and/or R-type VDCCs. The differentially distributed calcium channels may play a critical role in the induction of LTP at dendritic synapses of the hippocampal pyramidal cells.

To clarify the role of L-ascorbic acid (AsA) in the formation of pyridinoline, we examined the effects of AsA in vitro using soluble collagen and partially purified lysyl oxidase from bovine aorta. The concentration of dehydrodihydroxylysinonorleucine decreased when AsA was added in the early stage of pyridinoline formation. However, when AsA was added in a later stage of pyridinoline formation, the concentration of pyridinoline was not affected. These findings indicated that AsA was involved in the initial enzymatic reaction in pyridinoline synthesis. We purified lysyl oxidase to confirm its association of AsA. AsA inhibited the enzyme activity. Erythorbic acid and 3,4-dihydroxybenzoate suppressed the enzyme activity as well as AsA did. The inhibition by AsA of the lysyl oxidase activity arose from characteristics of AsA structure. AsA might be important in the regulation of the oxidative reaction of lysine.

We investigated whether oral administration of palmitoleate ameliorates disorders of lipid metabolism to clarify the effects of one of the components of fish oil. Lipid levels in the liver and plasma were significantly decreased by palmitoleate and by EPA administration. These results suggest that palmitoleate, in addition to EPA, plays a role in the regulation of lipid metabolism by fish oil.

Scope Resveratrol reportedly improves fatty liver. This study purposed to elucidate the effect of resveratrol on fatty liver in mice fed a high-fat (HF) diet, and to investigate the role of liver macrophages (Kupffer cells). Methods and results C57BL/6 mice were divided into three groups, receiving either a control diet, HF diet (50% fat), or HF supplemented with 0.2% resveratrol (HF + res) diet, for 8 weeks. Compared with the HF group, the HF + res group exhibited markedly attenuated fatty liver, and reduced lipid droplets (LDs) in hepatocytes. Proteomic analysis demonstrated that the most downregulated protein in the livers of the HF + res group was adipose differentiation-related protein (ADFP), which is a major constituent of LDs and reflects lipid accumulation in cells. The HF + res group exhibited greatly increased numbers of CD68(+) Kupffer cells with phagocytic activity. Immunohistochemistry showed that several CD68(+) Kupffer cells were colocalized with ADFP immunoreaction in the HF + res group. Additionally, the HF + res group demonstrated markedly decreased TNF-alpha production, which confirmed by both liver mononuclear cells stimulated by LPS in vitro and in situ hybridization analysis, compared with the HF group. Conclusion Resveratrol ameliorated fatty liver and increased CD68-positive Kupffer cells with downregulating ADFP expression.

Peroxisome proliferator-activated receptor gamma (PPARγ) responds to thiazolidinedione derivatives, which are ligands of PPARγ, and affects insulin resistance. Recently, a PPARγ study reported that in high-fat-diet-induced obesity, the phosphorylation of PPARγ prevented the transcription of specific PPARγ targets that have anti-obesity effects. We previously reported that genetic variants of the fatty acid desaturase were associated with plasma lipid profiles and could contribute to dyslipidemia in Japanese males. The aim of this study was to investigate the anti-obesity effects of PPARγ variants on lipid profiles. One hundred and thirty-eight (138) Japanese males participated in the study. Their serum lipid markers and the fatty acid composition of their red blood cell (RBC) membranes were determined. The stearoyl-CoA desaturase 1 (SCD1) indices were represented as the fatty acid product : precursor ratios. The participants were genotyped for the single-nucleotide polymorphism rs2938392 in the PPARγ gene. The participants' fitness habits were also surveyed by questionnaire. The effects of habitual exercise on the measured lipid parameters were compared in each genotype group. No association between the genotypes in the PPARγ gene and the biochemical data was found. However, the serum triglyceride levels and the SCD1 indices in RBC membranes were significantly higher in the participants who carried the major rs2938392 allele (A/A) and did not habitually exercise than in those who did exercise. These findings indicate that the risk for detrimental lipid profiles in the absence of habitual exercise depends on the PPARγ genotype in Japanese males.

A reduction of dehydroerythorbic acid (DERA) to erythorbic acid (ERA) in vitamin C-deficient guinea pigs was evaluated and compared with that of dehydroascorbic acid (DASA). Thirty-six guinea pigs were fed with vitamin C-deficient diets for 18 days. On day 19, the guinea pigs were divided into four groups for the administration of 100 mg of DERA, ERA, ascorbic acid (ASA), or DASA every day. After 12 days of oral administration, the concentration of DERA, ERA, ASA, and DASA in the liver, adrenal, spleen, kidney, and plasma of guinea pigs was determined by HPLC. A recovery from scurvy was measured in terms of weight gain and serum alkaline phosphatase activity. All four groups showed simi-lar recovery, indicating that the oral administration of relatively high concentrations of DERA reversed the effects of scurvy in vitamin C-deficient guinea pigs. In spite of DERA or DASA administration, ERA or ASA was mainly detected in the tissues. The reduction ratios of DEAR and DASA were similar (approximately 80%) in all tissues except spleen. These re-sults suggest that both DASA and DERA are taken up and reduced to ASA or ERA in vivo.

ビタミンC測定法, および血中の総ビタミンC値の基準値 (参考値) を検討した。健康な女子大生ボランティア54人に, 3日間の食事調査の後, 採血し, ビタミンCを1日200mg含む一定の試験食を3日間供した。3日後に再び採血を行い, 得られた血漿のビタミンC濃度を測定した。測定は3カ所の施設でHPLC法 (お茶の水女子大学, テイジンエスアールラボ) およびアスコルビン酸オキシダーゼ法 (東邦大学) を用いて行い, 各施設での測定値の比較も行った。総ビタミンC濃度の試験食摂取前値と後値では平均値に有意な差はみられないが, 後値ではばらつき (標準偏差) が小さくなり, ビタミンCの一定量摂取が, 血中濃度に影響を与えることが示唆された。前値でビタミンC濃度が低値にあった学生では, ビタミンCを1日200mg, 3日間摂取することで, 血中濃度は0.62mg/dL以上の範囲に入った。異なる測定方法による施設間差は認められず, 従って, 統計的に95%の信頼範囲から血中総ビタミンC濃度の基準値は0.70-1.38mg/dL (HPLC/ECD法) となった。この値は栄養所要量算出の際に基準とした値 (0.7mg/dL)とも一致した。

The interaction between intestinal epithelial cells andperipheral neuronal cells were examined using an invitro coculture system. Two cell lines, Caco-2 and PC12, were usedfor this experiment as an intestinal epithelial and entericneuronal cell model, respectively. By coculturing with fullydifferentiated Caco-2 cells, the neurite outgrowth was inducedin PC12 cells. This neurite outgrowth in PC12 was blocked byanti-nerve growth factor (NGF) polyclonal antibodies,suggesting that the neurite outgrowth in PC12 during thecoculture with Caco-2 cells was due to NGF secreted fromCaco-2 cells. On the other hand, coculturing with fullydifferentiated PC12 cells induced the decrease oftransepithelial electrical resistance in Caco-2 cellmonolayers. The permeability of lucifer yellow alsosignificantly increased, suggesting that the barrier functionand paracellular permeability of Caco-2 monolayers werealtered by coculturing with PC12 cells. The present studysuggests that this in vitro coculture system is a good modelfor the functional analysis of interaction among intestinalepithelial cells with different cell types.

A combination of a stereoselective addition of benzenethiol to α,β-unsaturated carboxylic acid derivatives and a subsequent substitution reaction of the corresponding sulfonium group with O-alkylhydroxamate anion has provided a new practical and stereoselective method for the construction of 3,4-disubstituted cis- and trans-β-lactams. A successful application was demonstrated by the formal asymmetric synthesis of (+)-PS-5.