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Cervical cancer is a human papilloma virus‐related disease, whereas endometrial cancer and atypical endometrial hyperplasia (AEH) are hormone‐related diseases, so co‐occurrence of the two is possible. However, scientific studies about such cases are rare. We encountered a case of cervical adenocarcinoma and AEH in a 33‐year‐old nulliparous woman. Two fertility‐sparing treatments were performed, a radical trachelectomy for the cervical cancer and high‐dose medroxyprogesterone acetate treatment for the AEH. After remission of the diseases, the patient became pregnant by in vitro fertilization and delivered a baby at 36 weeks' gestation by cesarean section. Although the patient had two uterine malignancies, proper evaluation of the diseases, consultation with the patient and her husband, and appropriate management led to fertility preservation, and live birth was achieved. [ABSTRACT FROM AUTHOR]

Introduction: In extremely and very preterm infants, predicting individual risks for adverse outcomes antenatally is challenging but necessary for risk-stratified perinatal management and parents' participation in decision-making about treatment. Our aim was to develop and validate prediction models for short-term (neonatal period) and medium-term (3 years of age) outcomes based on antenatal maternal and fetal factors alone.Material and Methods: A population-based study was conducted on 31 157 neonates weighing ≤1500 g and born between 22 and 31 weeks of gestation registered in the Neonatal Research Network of Japan during 2006-2015. Short-term outcomes were assessed in 31 157 infants and medium-term outcomes were assessed in 13 751 infants among the 31 157 infants. The clinical data were randomly divided into training and validation data sets in a ratio of 2:1. The prediction models were developed by factors selected using stepwise logistic regression from 12 antenatal maternal and fetal factors with the training data set. The number of factors incorporated into the model varied from 3 to 10, on the basis of each outcome. To evaluate predictive performance, the area under the receiver operating characteristics curve (AUROC) was calculated for each outcome with the validation data set.Results: Among short-term outcomes, AUROCs for in-hospital death, chronic lung disease, intraventricular hemorrhage (grade III or IV) and periventricular leukomalacia were 0.85 (95% CI 0.83-0.86), 0.80 (95% CI 0.79-0.81), 0.78 (95% CI 0.75-0.80), and 0.58 (95% CI 0.55-0.61), respectively. Among medium-term outcomes, AUROCs for cerebral palsy and developmental quotient of <70 at 3 years of age were 0.66 (95% CI 0.63-0.69) and 0.72 (95% CI 0.70-0.74), respectively.Conclusions: Although the predictive performance of these models varied for each outcome, their discriminative ability for in-hospital death, chronic lung disease, and intraventricular hemorrhage (grade III or IV) was relatively good. We provided a bedside prediction tool for calculating the likelihood of various infant complications for clinical use. To develop these prediction models would be valuable in each country, and these risk assessment tools could facilitate risk-stratified perinatal management and parents' shared understanding of their infants' subsequent risks. [ABSTRACT FROM AUTHOR]

Aim: Cancer treatment involves long‐term therapy and follow‐up, with mental disorders (MD) often affecting the treatment process. Hence, in this study, we retrospectively analyze cases involving gynecologic cancer with MD and clarify the relationship between psychosis and cancer prognosis. Methods: Patients with both gynecologic cancer and MD from January 2003 to August 2016 were recruited in this study. Cases were limited to those whose MD had been diagnosed before their cancer. Control patients without MD were also analyzed. Both cases and controls were adjusted for age, cancer type, and cancer stage. Results: A total of 54 patients with gynecologic cancer and MD, as well as 108 controls without MD, were included. The median age of the patients was 52 years. Details regarding cancer type were as follows: 11 ovarian cancers, 26 uterine corpus cancers and 17 cervical cancers. Among these, 25 schizophrenia cases, 15 depressive disorders, 4 bipolar disorders and 10 other MD were recorded. No significant differences in the 5‐year survival rate were found between patients and controls. In advanced‐stage cervical cancer, however, the prognosis was significantly poor given the low rate of initial treatment completion. Moreover, patients with advanced‐stage cervical cancer had significantly lower chemotherapy completion rates compared to those with other gynecologic malignancies. Conclusion: Mental disorders do not affect the prognosis of gynecologic cancers, except for advanced cervical cancer. Accordingly, improving the low rate of initial treatment completion seems to be a focal point for better prognosis in advanced cervical cancer. [ABSTRACT FROM AUTHOR]

Abstract Regional ductile deformation of the Sanbagawa belt is generally thought to be characterized by constrictional strain, based on strain analysis using deformed radiolarians in the low-grade regions. Similar strain analysis could not be carried out in the medium- to high-grade zones, because it is very difficult to identify individual radiolarians after strong recrystallization. However, discovery of the first known meta-conglomerate in the high-grade region of the Sanbagawa Belt allows quantitative 3-D strain to be estimated in this region. Using a development of the Rf-φ method, an evaluation of appropriate errors for this estimate can be determined. The principal strain ratios and estimated errors are X/Y = 5.4–6.6 and Y/Z = 3.8–3.9 implying deformation in the flattening field and refuting the idea of uniform constrictional strain. Semi-quantitative markers of the shape of the strain ellipse throughout the high-grade regions suggest that the deformation of the Sanbagawa Belt is dominantly in the flattening field. The difference with the earlier results may be due to late-stage overprinting by upright folding of the main ductile fabric in the low-grade region of western Shikoku. [ABSTRACT FROM AUTHOR]

Aim: Postpartum depression (PPD) and perinatal mental health care are of growing importance worldwide. Here we aimed to develop and validate machine learning models for the prediction of PPD, and to evaluate the usefulness of the recently adopted 2‐week postpartum checkup in some parts of Japan for the identification of women at high risk of PPD. Methods: A multicenter retrospective study was conducted using the clinical data of 10 013 women who delivered at ≥35 weeks of gestation at 12 maternity care hospitals in Japan. PPD was defined as an Edinburgh Postnatal Depression Scale score of ≥9 points at 4 weeks postpartum. We developed prediction models using conventional logistic regression and four machine learning algorithms based on the information that can be routinely collected in daily clinical practice. The model performance was evaluated using the area under the receiver operating characteristic curve (AUROC). Results: In the machine learning models developed using clinical data before discharge, the AUROCs were similar to those in the conventional logistic regression models (AUROC, 0.569–0.630 vs. 0.626). The incorporation of additional 2‐week postpartum checkup data into the model significantly improved the predictive performance for PPD compared to that without in the Ridge regression and Elastic net (AUROC, 0.702 vs. 0.630 [p < 0.01] and 0.701 vs. 0.628 [p < 0.01], respectively). Conclusions: Our machine learning models did not achieve better predictive performance for PPD than conventional logistic regression models. However, we demonstrated the usefulness of the 2‐week postpartum checkup for the identification of women at high risk of PPD. [ABSTRACT FROM AUTHOR]

Vesicular GABA transporter ( VGAT) is expressed in GABAergic and glycinergic neurons, and is responsible for vesicular storage and subsequent exocytosis of these inhibitory amino acids. In this study, we show that VGAT recognizes β-alanine as a substrate. Proteoliposomes containing purified VGAT transport β-alanine using Δψ but not ΔpH as a driving force. The Δψ-driven β-alanine uptake requires Cl−. VGAT also facilitates Cl− uptake in the presence of β-alanine. A previously described VGAT mutant (Glu213Ala) that disrupts GABA and glycine transport similarly abrogates β-alanine uptake. These findings indicated that VGAT transports β-alanine through a mechanism similar to those for GABA and glycine, and functions as a vesicular β-alanine transporter. [ABSTRACT FROM AUTHOR]

J. Neurochem. (2011) 119, 1-5. Abstract Sialin, the protein coded by SLC17A5, is responsible for membrane potential (Δψ)-driven aspartate and glutamate transport into synaptic vesicles in addition to H+/sialic acid co-transport in lysosomes. Rodent sialin mutants harboring the mutations associated with Salla disease in humans did not transport aspartate and glutamate whereas H+/sialic acid co-transport activity was about one-third of the wild-type protein. In this study, we investigate the effects of various mutations on the transport activities of human sialin. Proteoliposomes containing purified heterologously expressed human sialin exhibited both Δψ-driven aspartate and glutamate transport activity and H+/sialic acid co-transport activity. Aspartate and glutamate transport was not detected in the R39C and K136E mutant forms of SLC17A5 protein associated with Salla disease, whereas H+/sialic acid co-transport activity corresponded to 30-50% of the recombinant wild-type protein. In contrast, SLC17A5 protein harboring the mutations associated with infantile sialic acid storage disease, H183R and Δ268SSLRN272 still showed normal levels of Δψ-driven aspartate and glutamate transport even though H+/sialic acid co-transport activity was absent. Human sialin carrying the G328E mutation that causes both phenotypes, and P334R and G378V mutations that cause infantile sialic acid storage disease showed no transport activity. These results support the idea that people suffering from Salla disease have been defective in aspartergic and glutamatergic neurotransmissions. [ABSTRACT FROM AUTHOR]

Objective: To clarify the decrease in response to controlled ovarian stimulation in patients who receive in vitro fertilization treatment after radical trachelectomy. Methods: The outcomes of ovarian stimulation were retrospectively evaluated and compared between patients who have undergone radical trachelectomy and control patients who had male factor infertility or unexplained infertility. Results: A total of 30 ovarian stimulation cycles in 14 radical trachelectomy patients and 54 cycles in 30 control patients were reviewed. The median age at ovarian stimulation was 34.8 years in the radical trachelectomy group and 36.5 years in the control group. Compared with the control group, the radical trachelectomy group had significantly lower mean estradiol concentration (1461.7 pg/ml, SD 775.0 vs. 1950.9 pg/ml, SD 1057.3, P = 0.029) during controlled ovarian stimulation cycle and smaller median number of retrieved oocytes (5, range 1–14 vs. 8, range 1–19, P = 0.007), despite the higher use of gonadotropin (3527.5 IU, SD 1313.4 vs. 2670.8 IU, SD 905.1, P = 0.001). Conclusion: The response to controlled ovarian stimulation decreased after radical trachelectomy. Synopsis: The response to controlled ovarian stimulation decreased after radical trachelectomy. [ABSTRACT FROM AUTHOR]

Objective The ketogenic diet is clinically used to treat drug-resistant epilepsy. The diet treatment markedly increases ketone bodies (acetoacetate and β-hydroxybutyrate), which work as energy metabolites in the brain. Here, we investigated effects of acetoacetate on voltage-dependent Ca2+ channels ( VDCCs) in pyramidal cells of the hippocampus. We further explored an acetoacetate analog that inhibited VDCCs in pyramidal cells, reduced excitatory postsynaptic currents ( EPSCs), and suppressed seizures in vivo. Methods The effects of acetoacetate and its analogs on VDCCs and EPSCs were evaluated using patch-clamp recordings from CA1 pyramidal cells of mouse hippocampal slices. The in vivo effects of these reagents were also evaluated using a chronic seizure model induced by intrahippocampal injection of kainate. Results Acetoacetate inhibited VDCCs in pyramidal cells of hippocampal slices, and reduced EPSCs in slices exhibiting epileptiform activity. More potent EPSC inhibitors were then explored by modifying the chemical structure of acetoacetate, and 2-phenylbutyrate was identified as an acetoacetate analog that inhibited VDCCs and EPSCs more potently. Although acetoacetate is known to inhibit vesicular glutamate transporters ( VGLUTs), 2-phenylbutyrate did not inhibit VGLUTs, showing that 2-phenylbutyrate is an acetoacetate analog that preferably inhibits VDCCs. In addition, 2-phenylbutyrate markedly reduced EPSCs in slices exhibiting epileptiform activity, and suppressed hippocampal seizures in vivo in a mouse model of epilepsy. The in vivo antiseizure effects of 2-phenylbutyrate were more potent than those of acetoacetate. Finally, intraperitoneal 2-phenylbutyrate was delivered to the brain, and its brain concentration reached the level enough to reduce EPSCs. Significance These results demonstrate that 2-phenylbutyrate is an acetoacetate analog that inhibits VDCCs and EPSCs in pyramidal cells, suppresses hippocampal seizures in vivo, and has brain penetration ability. Thus 2-phenylbutyrate provides a useful chemical structure as a lead compound to develop new antiseizure drugs originating from ketone bodies. [ABSTRACT FROM AUTHOR]

Objective Serum uric acid (SUA) levels in humans are mainly regulated by urate transporters. Recent genome-wide association studies suggested that common variants of the human sodium-dependent phosphate cotransporter type 1 gene ( NPT1/SLC17A1) influence SUA. NPT1 has been reported to mediate urate transport, but its physiologic role in regulating SUA in humans remains unclear. Furthermore, the findings of replication studies of the relationship between NPT1 variants and gout have been inconsistent. The aims of this study were to investigate the effect of NPT1 on gout and to determine its physiologic role. Methods Five hundred forty-five male Japanese patients with gout and 1,115 male Japanese control subjects were genotyped for rs1165196 (I269T), a common missense variant in NPT1. Analyses of the association between rs1165196 and gout were then conducted, focusing especially on renal underexcretion (RUE) gout. Immunohistochemical analysis and functional analysis using Xenopus oocytes were also performed. Results Single-nucleotide polymorphism rs1165196 significantly decreased the risk of RUE gout (odds ratio 0.73, P = 0.031) but did not confer a risk for all gout ( P = 0.123). The immunohistochemical analysis revealed that human NPT1 is localized to the apical membrane of the renal proximal tubule. The functional analysis using Xenopus oocyte expression systems showed that rs1165196 increases NPT1-mediated urate export. Conclusion This study showed that NPT1 is a urate exporter located in the renal proximal tubule in humans, and that its common gain-of-function variant, rs1165196, causes RUE gout, a major subtype of gout. These findings enable us to deepen our understanding of the physiologic role of NPT1 as a renal urate exporter as well as its pathophysiologic role in gout. [ABSTRACT FROM AUTHOR]

Nucleotides are stored in the dense granules of platelets. The release of nucleotides triggers one of the first steps in a series of cascades responsible for blood coagulation. However, the mechanism of how the nucleotides are accumulated in the granules is still far less understood. The transporter protein responsible for storage of nucleotides in the neuroendocrine cells has been identified and characterized. We hypothesized that the vesicular nucleotide transporter ( VNUT) is also involved in the vesicular storage of nucleotides in platelets. In this article, we present three lines of evidence that VNUT is responsible for the vesicular storage of nucleotides in platelets and that vesicular ATP transport is crucial for platelet function, detection and characterization of VNUT activity in platelets isolated from healthy humans and MEG-01 cells, RNA interference experiments on MEG-01 cells, and studies on nucleotide transport and release with a selective inhibitor. [ABSTRACT FROM AUTHOR]

The article discusses the findings of a study which demonstrated the function of transient receptor potential vanilloid 4 (TRPV4) in causing the release of adenosine triphosphate (ATP) from oesophageal cells. The experiment confirmed that TRPV4 has the ability to detect warm temperature, stretch, and chemical presence in mouse oesophagus. The article also suggests the possible action of TRPV4 in the hypersensitivity of the oesophagus to heat and mechanical stimuli.

Abstract: The rate at which X-ray structures of membrane proteins are solved is on a par with that of soluble proteins in the late 1970s. There are still many obstacles facing the membrane protein structural community. Recently, there have been several technical achievements in the field that have started to dramatically accelerate structural studies. Here, we summarize these so-called ‘tricks-of-the-trade’ and include case studies of several mammalian transporters. [Copyright &y& Elsevier]

Osteoclasts are involved in the catabolism of the bone matrix and eliminate the resulting degradation products through transcytosis, but the molecular mechanism and regulation of transcytosis remain poorly understood. Upon differentiation, osteoclasts express vesicular glutamate transporter 1 (VGLUT1), which is essential for vesicular storage and subsequent exocytosis of glutamate in neurons. VGLUT1 is localized in transcytotic vesicles and accumulates L-glutamate. Osteoclasts secrete L-glutamate and the bone degradation products upon stimulation with KCl or ATP in a Ca2+-dependent manner. KCl- and ATP-dependent secretion of L-glutamate was absent in osteoclasts prepared from VGLUT1−/− knockout mice. Osteoclasts express mGluR8, a class III metabotropic glutamate receptor. Its stimulation by a specific agonist inhibits secretion of L-glutamate and bone degradation products, whereas its suppression by a specific antagonist stimulates bone resorption. Finally, it was found that VGLUT1−/− mice develop osteoporosis. Thus, in bone-resorbing osteoclasts, L-glutamate and bone degradation products are secreted through transcytosis and the released L-glutamate is involved in autoregulation of transcytosis. Glutamate signaling may play an important role in the bone homeostasis. [ABSTRACT FROM AUTHOR]

Vesicular glutamate transporter (VGLUT) is responsible for the vesicular storage ofl-glutamate, and plays an essential role in glutamate-mediated intercellular signal transmission in the CNS and in some neuroendocrine cells. Intestinal L cells are the glucose-responsive neuroendocrine cells responsible for the secretion of glucagon-like peptide 1 (GLP-1). We have shown that intestinal L cells express VGLUT2, a VGLUT isoform, which suggests that L cells secretel-glutamate. In the present study, we investigated this possibility using GLUTag mouse clonal L cells. RT–PCR and northern blot analyses revealed expression of the VGLUT1 and VGLUT2 genes, but not of the VGLUT3 gene. Western blot analysis revealed immunological counterparts for VGLUT2, whereas an immunological counterpart of VGLUT1 was not detected. Indirect immunofluorescence microscopy revealed a punctate distribution of VGLUT2 immunoreactivity throughout the cells, which co-localized with GLP-1. Double-labeling immunoelectronmicroscopy confirmed the association of VGLUT2 with GLP-1-containing secretory granules. The membrane fraction exhibited ATP-dependentl-glutamate uptake, which was sensitive to bafilomycin A1 (a vacuolar proton ATPase inhibitor) and Evans blue (a VGLUT inhibitor) but insensitive tod,l-aspartate. Upon depolarization with KCl, GLUTag cells secreted appreciable amounts ofl-glutamate and GLP-1.d-Glucose and methyl-α-d-glucopyranoside, stimulators of exocytosis of GLP-1, also triggered the secretion ofl-glutamate. Thel-glutamate secretion was partially dependent on Ca2+ and sensitive to bafilomycin A1. These results demonstrated that GLUTag cells storedl-glutamate in secretory granules and secreted it with GLP-1 by exocytosis. As GLUTag cells and intestinal L cells express kainate receptors and plasma membrane glutamate transporters, these results support the concept ofl-glutamate-mediated intercellular signaling in the vicinity of intestinal L cells. [ABSTRACT FROM AUTHOR]

Amphiphysin is a major dynamin-binding partner at the synapse; however, its function in fission is unclear. Incubation of large unilamellar liposomes with mice brain cytosol led to massive formation of small vesicles, whereas cytosol of amphiphysin 1 knockout mice was much less efficient in this reaction. Vesicle formation from large liposomes by purified dynamin was also strongly enhanced by amphiphysin. In the presence of liposomes, amphiphysin strongly affected dynamin GTPase activity and the recruitment of dynamin to the liposomes, but this activity was highly dependent on liposome size. Deletion from amphiphysin of its central proline-rich stretch dramatically potentiated its effect on dynamin, possibly by relieving an inhibitory intramolecular interaction. These results suggest a model in which maturation of endocytic pits correlates with the oligomerization of dynamin with either amphiphysin or other proteins with similar domain structure. Formation of these complexes is coupled to the activation of dynamin GTPase activity, thus explaining how deep invagination of the pit leads to fission. [ABSTRACT FROM AUTHOR]

5-Hydroxytryptamine (5-HT) is a precursor and a putative modulator for melatonin synthesis in mammalian pinealocytes. 5-HT is present in organelles distinct from L-glutamate-containing synaptic-like microvesicles as well as in the cytoplasm of pinealocytes, and is secreted upon stimulation by norepinephrine (NE) to enhance serotonin N-acetyltransferase activity via the 5-HT[sub 2] receptor. However, the mechanism underlying the secretion of 5-HT from pinealocytes is unknown. In this study, we show that NE-evoked release of 5-HT is largely dependent on Ca[sup 2+] in rat pinealocytes in culture. Omission of Ca[sup 2+] from the medium and incubation of pineal cells with EGTA-tetraacetoxymethyl-ester inhibited by 59 and 97% the NE-evoked 5-HT release, respectively. Phenylephrine also triggered the Ca[sup 2+]-dependent release of 5-HT, which was blocked by phentolamine, an α antagonist, but not by propranolol, a β antagonist. Botulinum neurotoxin type E cleaved 25 kDa synaptosomal-associated protein and inhibited by 50% of the NE-evoked 5-HT release. Bafilomycin A1, an inhibitor of vacuolar H[sup +]-ATPase, and reserpine and tetrabenazine, inhibitors of vesicular monoamine transporter, all decreased the storage of vesicular 5-HT followed by inhibition of the NE-evoked 5-HT release. Agents that trigger L-glutamte exocytosis such as acetylcholine did not trigger any Ca[sup 2+]-dependent 5-HT release. Vice versa neither NE nor phenylephrine caused synaptic-like microvesicle-mediated L-glutamate exocytosis. These results indicated that upon stimulation of a adrenoceptors pinealocytes secrete 5-HT through a Ca[sup 2+]-dependent exocytotic mechanism, which is distinct from the exocytosis of synaptic-like microvesicles. [ABSTRACT FROM AUTHOR]

The sperm acrosome exhibits a low pH. However, the mechanism of acidification in the acrosome remains unclear. Vacuolar-type proton ATPase (V-ATPase) has been shown to play a principle role in generating and maintaining the acidity of organelles such as lysosomes and endosomes. In this study, we examined whether V-ATPase is localized in the acrosome membranes using immunohistochemical techniques. Sections of rat testis were immunostained using antibodies against V-ATPase. Under light microscopic observation, the perinuclear region in spermatids at an early stage of development was heavily immunostained. At the electron microscopic level, gold particles showing the presence of V-ATPase were localized to the acrosome membranes in the developing spermatids. V-ATPase was also localized to the membrane of vesicles locating between the trans-Golgi area and the acrosome. These observations suggest that V-ATPase may play a role in acrosome acidification. [ABSTRACT FROM AUTHOR]

Abstract: The mammalian pineal gland uses L-glutamate as an intercellular chemical transmitter to regulate negatively melatonin synthesis. To receive glutamate signals, pinealocytes express at least three kinds of glutamate receptors: metabotropic receptor types 3 and 5 and an ionotropic receptor, GluR1. In this study, we examined whether or not the fourth class of ionotropic receptor, δ, which is known for its nondefinitive molecular function and its unique expression pattern in brain, is expressed in pineal gland. RT-PCR analyses with specific probes indicated the expression of mRNA of δ2 but not that of δ1 in pineal gland and cultured pineal cells. Western blotting analysis with polyclonal antibodies specific to the carboxyl-terminal region of the δ2 receptor recognized a single 110-kDa polypeptide of cerebellar membranes and specifically immunostained Purkinje cells. The δ2 antibodies recognized a 110-kDa polypeptide of pineal membranes and specifically immunostained huge glial-like cells with the occasional presence of several long, branching processes in a pineal cell culture. δ2 is not uniformly distributed throughout the cells and is relatively abundant at the periphery of the cell bodies and long processes, where the terminals of synaptophysin-positive processes of pinealocytes, a site for glutamate secretion, are frequently present. The δ2-positive cells constitute a very minor population among total pineal cells (∼0.03%). Double immunolabeling with δ2 antibodies and antibodies against marker proteins for pineal interstitial cells clearly distinguishes δ2-positive pineal cells and other known interstitial cells, including glial fibrillary acidic protein- or vimentin-positive glial-like cells. These results indicated that the δ2 glutamate receptor is expressed in a novel subpopulation of pineal glial-like cells in culture and suggest the presence of a glutamate-mediated intercellular... [ABSTRACT FROM AUTHOR]

Abstract: Rat pinealocytes receive noradrenergic innervation that stimulates melatonin synthesis. Besides melatonin, we showed previously that pinealocytes accumulate L-glutamate in microvesicles and secrete it through an exocytic mechanism. The secreted glutamate binds to the class II metabotropic glutamate receptor and inhibits norepinephrine-stimulated melatonin synthesis in neighboring pinealocytes through an inhibitory cyclic AMP cascade. In this study, it was found that, in addition to metabotropic receptors, pinealocytes express functional ionotropic receptors. RT-PCR and northern analyses indicated the expression of mRNA for GluR1, KA2, and NR2C in pineal gland. The presence of GluR1 protein was confirmed by immunological techniques, but neither KA2 nor NR2C was detected. Consistent with this observation, the presence of (RS)-α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid or kainate, non-N-methyl-D-aspartate receptor agonists, transiently stimulated increased the intracellular Ca2+ concentration of cultured pinealocytes, whereas N-methyl-D-aspartate did not. These responses were prevented by 6-cyano-7-nitroquinoxaline-2,3-dione, a selective antagonist for non-N-methyl-D-aspartate receptors, by L-type Ca2+ channel blockers such as nifedipine, or by omitting Ca2+ or Na+ in the medium. In the presence of Ca2+ and Na+, (RS)-α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid or kainate evoked glutamate secretion from the cultured cells, which was prevented by 6-cyano-7-nitroquinoxaline-2,3-dione, L-type Ca2+ channel blockers, type E or B botulinum neurotoxin, or incubation at <20°C. These results strongly suggest that GluR1 is functionally expressed in pinealocytes and triggers microvesicle-mediated exocytosis of L-glutamate via activation of L-type Ca2+ channels. It is possible that GluR1 participates in a signaling cascade that enhances and expands the L-glutamate signal throughout the pineal gland. [ABSTRACT FROM AUTHOR]

Abstract: Vesicular monoamine transporters (VMATs) are involved in chemical transduction in monoaminergic neurons and various endocrine cells through the storage of monoamines in secretory vesicles. Mammalian pinealocytes contain more 5-hydroxytryptamine (5-HT) than any other cells and are expected on contain VMAT, although no information is available so far. Upon the addition of ATP, radiolabeled 5-HT was taken up by a particulate fraction prepared from cultured rat pinealocytes. The 5-HT uptake was inhibited significantly by bafilomycin A1 (an inhibitor of vacuolar H+-ATPase), 3,5-di-tert-butyl-4-hydroxybenzyli-denemalononitrile (a proton conductor), or reserpine (an inhibitor of VMAT). RT-PCR analysis suggested that VMAT type 1 (VMAT1), but not type 2, is expressed. Antibodies against VMAT1 recognized a single polypeptide with an apparent molecular mass of ~55 kDa, and specifically immunostained pinealocytes. VMAT1 immunoreactivity was high in the vesicular structures in the varicosities of long branching processes and was associated with 5-HT, but not with synaptophysin, a marker protein for microvesicles. The 5-HT immunoreactivity in the long branching processes disappeared upon incubation with reserpine. These results indicate that 5-HT, at least in part, is stored in vesicles other than microvesicles in pinealocytes through a mechanism similar to that of various secretory vesicles. [ABSTRACT FROM AUTHOR]