Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01185 (vasopressin)
 23,126 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Biologically active peptides and neurotransmitter substances were added to anterior pituitary cell cultures to examine the presence of corticotropin releasing factor (CRF)-like activity. Hypothalamic extract (HE) induced significant dose-related increase of ACTH, and the lowest effective dose was 0.01 HE/ml. Other tested substances including luteinizing hormone-releasing hormone, thyrotropin releasing hormone, melanocyte stimulating hormone release inhibiting factor, somatostatin, substance P, neurotensin, beta-endorphin. leu-enkephalin, met-enkephalin, bradykinin, norepinephrine, dopamine, serotonin, acetylcholine, histamine, gamma-amino butyric acid or gamma-hydroxy butyric acid showed no CRF-like activity. Relatively high doses of lysine vasopressin, arginine vasopressin and angiotensin II increased the release of ACTH in pituitary cell cultures, but the maximal ACTH response was markedly less than with HE. These results indicate that cultured anterior pituitary cells are sensitive and fairly specific in detecting CRF(s) comparing with other detecting procedures.
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PMID:Specificity of cultured anterior pituitary cells in detecting corticotropin releasing factor(s): the effect of biologically active peptides and neurotransmitter substances on ACTH release in pituitary cell cultures. 3 34

Pituitaries of the African catfish, Clarias gariepinus, were prefixed in aldehyde fixatives, frozen in liquid propane and submitted to a cryosubstitution procedure. Ultrathin sections of the Lowicryl HM20-embedded tissue were treated with primary antisera raised in rabbits to gonadotropin releasing hormone (GnRH), vasopressin or gamma amino butyric acid (GABA) respectively. Binding of the primary antisera was visualized with goat anti-rabbit (GAR) labeled with gold. The general morphology of the tissue components in the cryosubstituted pituitaries matches with that obtained after routine embedding procedures. In addition, a strong labeling intensity of the neuropeptides/neurotransmitters investigated in the present study was demonstrated. Due to these qualities cryosubstitution provides optimal conditions for studying co-localization of neurosecretory products, using double-immunostaining procedures. In the pars distalis of the catfish pituitary several types of hypothalamus-derived nerve fibers are present between or synapting on the secretory cells. It is demonstrated that the two known catfish GnRHs are co-localized in the same nerve fiber and within these nerve fibers even co-exist in the same neurosecretory granules. GABA and vasopressin-immunolabeling each occurred in different nerve fibers. The present data demonstrate that cryosubstitution and low temperature-embedding results in an excellent morphological preservation compared to ultracryotomy and a better preserved immunoreactivity of small antigenic molecules in comparison to conventional fixation and embedding techniques.
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PMID:Application of cryosubstitution in neurohormone- and neurotransmitter-immunocytochemistry. 155 44

Colonic biopsy specimens were obtained from patients undergoing surgery for carcinoma of the rectum. Colonic resistance arteries (internal diameter 178-345 microns) were dissected out under the microscope and mounted in a microvascular myograph capable of measuring isometric tension development. Experiments were designed to test compounds trophic to the gastrointestinal tract--namely, glutamine and the three short chain fatty acids, acetic, propionic, and butyric acid, for effects on vascular tone. Glutamine in concentrations up to 30 mM neither constricted nor dilated the resistance arteries. The three short chain fatty acids alone and in combination, however, caused a concentration-dependent (range 0.1-30 mM) dilatation of resistance arteries preconstricted with 50 mM K+, and this relaxant effect was unaffected by removal of the endothelium, presence of indomethacin, and preconstriction with vasopressin. These data suggest that the trophic effect of glutamine on intestinal mucosa cannot be explained through actions of this compound on the resistance vasculature. In contrast, the relaxant effect of short chain fatty acids on resistance arteries in vitro suggests that these compounds may be able to improve the colonic microcirculation in vivo, thereby providing an explanation for their trophic effect on intestinal mucosa.
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PMID:Short chain fatty acids dilate isolated human colonic resistance arteries. 226 80

Stimulation of the nucleus tractus solitarius (NTS) excites putative vasopressin-secreting cells of the supraoptic nucleus (SON) via a catecholaminergic projection to hypothalamus. Despite recent evidence of a direct catecholaminergic projection from NTS to SON, we have performed single-unit recording experiments in pentobarbital sodium-anesthetized rats to investigate the possibility that NTS stimulation effects on SON vasopressin cells are indirect, being relayed via the A1 noradrenergic cell group of the caudal ventrolateral medulla. The effects of single-pulse NTS and A1 region stimulation on the activity of antidromically identified SON neurosecretory cells that had been functionally characterized as vasopressin secreting were compared. NTS stimulation excited 81% of all putative vasopressin-secreting cells tested (n = 83), with a mean onset latency of 51 +/- 1 ms. A1 region stimulation excited 76% of all cells tested and 90% of units responsive to NTS stimulation, with a mean latency of 39 +/- 1 ms. Consistent with previous work NTS stimulation excited only a minority of oxytocin cells tested (3/13), and of these two-thirds also responded to A1 stimulation. Bilateral electrolytic lesions of the A1 region abolished the effects of NTS stimulation on putative vasopressin cells. Ipsilateral A1 region injections of the inhibitory neurotransmitter gamma-amino-butyric acid reversibly blocked NTS stimulation effects on putative vasopressin cells in animals where the contralateral A1 region had already been lesioned. These results support the proposal that excitation of SON vasopressin-secreting cells after NTS stimulation is due to activation of a relay projection through the A1 noradrenergic cell group of the caudal ventrolateral medulla.
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PMID:A1 cell group mediates solitary nucleus excitation of supraoptic vasopressin cells. 258 28

Rat aortic smooth muscle cells in culture (A-10; ATCC CRL 1476) exhibited low levels of beta-adrenergic receptors as determined by specific binding of [125I]cyanopindolol ([125I]CYP) and marginal stimulation of adenylate cyclase in plasma membranes by (-)isoproterenol. When these cells were exposed to 5 mM sodium butyrate, the number of beta-adrenergic receptors and the beta-agonist-stimulated adenylate cyclase activity increased markedly. However, basal, GTP, Gpp(NH)p, and fluoride-stimulated activities did not change. The induction of beta-adrenergic receptors and beta-agonist stimulated adenylate cyclase activity was time- and dose-dependent, and was relatively specific for sodium butyrate. Propionate and valerate were less effective than butyrate, while isobutyrate, succinate, and malonate were ineffective. The induction involved RNA and protein synthesis because induction was prevented by treatment with cycloheximide, puromycin, and actinomycin D. Butyrate did not cause a general increase in cell surface receptors, because the number of vasopressin receptors did not change. The sustained presence of butyrate appeared to be necessary for the maintenance of the induced beta-receptors. When butyrate was removed, receptor number and beta-agonist-stimulated adenylate cyclase activity were decreased by 90% over 24 hr. We conclude that the poor response of rat aortic smooth muscle cell plasma membranes to beta-adrenergic agonists is due to the presence of a low number of beta-adrenergic receptors. Butyrate markedly increased the number of beta-receptors which resulted in a proportional increase in beta-agonist-stimulated adenylate cyclase activity. The increase in receptor number was dependent on RNA and protein synthesis. Butyrate treatment did not affect the activity of the cyclase unit and the efficiency of coupling between the receptors and the guanine nucleotide regulatory protein, Ns.
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PMID:Induction of functional beta-adrenergic receptors in rat aortic smooth muscle cells by sodium butyrate. 302 40

Rat pituitary neural lobe contained high concentrations of cholecystokinin-like immunoreactivity (CCK-LI). Section of the pituitary stalk resulted in loss of CCK-LI, and both lactation and replacement of drinking water with 2% saline resulted in marked depletion of CCK-LI. Rats with congenital diabetes insipidus (Brattleboro strain) had a 73% reduction in CCK-LI below the levels of hooded Long-Evans controls, where as levels in the brain were unchanged. Release of CCK-LI, labeled dopamine, and gamma-amino butyric acid in response to potassium depolarization was studied. There was a low fractional release of CCK-LI. Addition of sulfated CCK-8 (CCK-8s) to the medium enhanced the calcium-dependent potassium-stimulated release of dopamine, but basal release was unaffected. gamma-Amino butyric acid release was only poorly calcium dependent and not effected by extracellular CCK-8s. Vasopressin and oxytocin release were stimulated by electrical stimulation of the pituitary stalk, and were unaffected by the addition of CCK-8s to the medium. In vivo, however, the injection of 5 micrograms CCK-8s into the third ventricle resulted in increased plasma vasopressin concentrations.
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PMID:Localization and actions of cholecystokinin in the rat pituitary neurointermediate lobe. 632 36

Since prolactin (PRL) can increase electrically stimulated oxytocin (OT) release by a direct action on the neurohypophysis, experiments were done to test the effect of PRL on OT mRNA content of explants of the hypothalamo-neurohypophyseal system (HNS) obtained from Day 10 lactating Sprague-Dawley rats, to determine if PRL could alter OT mRNA by a direct effect on the HNS. The effect of PRL was evaluated alone and in conjunction with bicuculline, an antagonist at gamma amino butyric acid receptors, in order to provide a concomitant stimulus for OT release. Neither PRL nor bicuculline alone altered OT or VP release. However, the simultaneous administration of bicuculline and PRL caused a statistically significant increase in the release of OT and in OT mRNA content of the explants (P < 0.05). On the other hand, PRL did not cause vasopressin (VP) release nor an increase in VP mRNA in these explants even in the presence of bicuculline, thus ruling out a direct effect of PRL on the HNS VP neurons. In conclusion, during lactation, PRL, in combination with other stimuli can increase OT mRNA content in the hypothalamus by a direct action on the hypothalamo-neurohypophyseal system. This effect may be secondary to the release of OT. This effect is specific to OT, because PRL did not alter either the release of VP or VP mRNA content.
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PMID:Prolactin modulates oxytocin mRNA during lactation by its action on the hypothalamo-neurohypophyseal axis. 774 45

Lactation is associated with complex changes of the hypothalamo-neurohypophysial system, and oxytocin released within the hypothalamic supraoptic (SON) and paraventricular nuclei may serve as a signal of communication between the magnocellular nuclei in lactating rats. In the first study, the intranuclear and peripheral release patterns of oxytocin and vasopressin in response to intraperitoneal hypertonic saline were studied in virgin and lactating rats to determine if the reduced osmoresponsiveness of the oxytocinergic and vasopressinergic systems during lactation is reflected by reduced release not only into blood, but also within the SON. Simultaneous microdialysis was performed within the SON and the jugular vein before and up to 6 hr after peripheral osmotic stimulation (3.0 M NaCl, 0.6 ml/100 gm body weight, i.p.). There was an immediate increase in secretion of both oxytocin and vasopressin into blood, whereas peptide release within the SON was delayed and peaked after 4-5 hr. Peripheral release of both peptides was significantly reduced in lactating animals, whereas within the SON release of oxytocin, but not vasopressin, was significantly reduced during lactation. In the second study, cross talk between the SONs--another phenomenon which seems to be characteristic for lactation--was studied. Microdialysis of one SON with hypertonic perfusion medium (with 1 M NaCl) significantly increased the release of oxytocin, vasopressin, and various amino acids (aspartate, glutamate, serine, glutamine, gamma amino butyric acid, and arginine) within the ipsilateral SON. In contrast to virgin female and male animals, this unilateral stimulation of the SON resulted in a transiently increased release of oxytocin in the contralateral SON of lactating rats. The release of vasopressin and amino acids within the contralateral SON of lactating rats remained unchanged, indicating specific activation of contralateral oxytocinergic neurons.
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PMID:Osmotic responsiveness and cross talk involving oxytocin, but not vasopressin or amino acids, between the supraoptic nuclei in virgin and lactating rats. 775 20

GABA (gamma-amino-butyric acid) is the predominant neurotransmitter in the mammalian suprachiasmatic nucleus (SCN), with a central role in circadian time-keeping. We therefore undertook an ultrastructural analysis of the GABA-containing innervation in the SCN of mice and rats using immunoperoxidase and immunogold procedures. GABA-immunoreactive (GABA-ir) neurons were identified by use of anti-GABA and anti-GAD (glutamic acid decarboxylase) antisera. The relationship between GABA-ir elements and the most prominent peptidergic neurons in the SCN, containing vasopressin-neurophysin (VP-NP) or vasoactive intestinal polypeptide (VIP), was also studied. Within any given field in the SCN, approximately 40-70% of the neuronal profiles were GABA-ir. In GABA-ir somata, immunogold particles were prominent over mitochondria, sparse over cytoplasm, and scattered as aggregates over nucleoplasm. In axonal boutons, gold particles were concentrated over electron-lucent synaptic vesicles (diameter 40-60 nm) and mitochondria, and in some instances over dense-cored vesicles (DCVs, diameter 90-110 nm). GABA-ir boutons formed either symmetric or asymmetric synaptic contacts with somata, dendritic shafts and spines, and occasionally with other terminals (axo-axonic). Homologous or autaptic connections (GABA on GABA, or GAD on GAD) were common. Although GABA appeared to predominate in most neuronal profiles, colocalisation of GABA within neurons that were predominantly neuropeptide-containing was also evident. About 66% of the VIP-containing boutons and 32% of the vasopressinergic boutons contained GABA. The dense and complex GABAergic network that pervades the SCN is therefore comprised of multiple neuronal phenotypes containing GABA, including a wide variety of axonal boutons that impinge on heterologous and homologous postsynaptic sites.
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PMID:Morphological heterogeneity of the GABAergic network in the suprachiasmatic nucleus, the brain's circadian pacemaker. 1069 83

Previous experiments have shown that a 10-min forced swimming session triggers the release of vasopressin from somata and dendrites, but not axon terminals, of neurons of the hypothalamic-neurohypophysial system. To further investigate regulatory mechanisms underlying this dissociated release, we forced male Wistar rats to swim in warm (20 degrees C) water and monitored release of the potentially inhibitory amino acids gamma amino butyric acid (GABA) and taurine into the hypothalamic supraoptic nucleus using microdialysis. Forced swimming caused a significant increase in the release of taurine (up to 350%; P < 0.05 vs. prestress release), but not GABA. To reveal the physiological significance of centrally released taurine, the specific taurine antagonist 6-aminomethyl-3-methyl-4H-1,2,4-benzothiadiazine-1,1-dioxide was administered into the supraoptic nucleus via retrodialysis. Administration of this antagonist caused a significant increase in the release of vasopressin within the supraoptic nucleus and into the blood both under basal conditions and during stress (up to 800%; P < 0.05 vs. basal values), without affecting hypothalamic or plasma oxytocin. Local administration of the GABA(A) receptor antagonist bicuculline, in contrast, failed to influence vasopressin secretion at either time point. In a separate series of in vivo electrophysiological experiments, administration of the same dosage of the taurine antagonist into the supraoptic nucleus via microdialysis resulted in an increased electrical activity of identified vasopressinergic, but not oxytocinergic, neurons. Taken together our data demonstrate that taurine is released within the supraoptic nucleus during physical/emotional stress. Furthermore, at the level of the supraoptic nucleus, taurine inhibits not only the electrical activity of vasopressin neurons but also acts as an inhibitor of both central and peripheral vasopressin secretion during different physiological states.
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PMID:Taurine selectively modulates the secretory activity of vasopressin neurons in conscious rats. 1168 96


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