Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01178 (oxytocin)
 15,767 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Characterization of specific vasopressin binding sites was investigated in purified mouse Leydig cells using tritiated arginine-vasopressin. Binding of radioligand was saturable, time- and temperature-dependent and reversible. (3H)-AVP was found to bind to a single class of sites with high affinity (Kd = 2.20 +/- 0.18 nM) and low capacity (Bmax = 17.4 +/- 1.8 fmol/10(6) Leydig cells). Binding displacements with specific selective analogs of AVP indicated the presence of V1 subtype receptors on Leydig cells. The ability of AVP to displace (3H)-AVP binding was greater than LVP and oxytocin. The unrelated peptides, somatostatin and substance P, were less potent, while neurotensin and LHRH did not displace (3H)-AVP binding. The time-course effects of AVP-pretreatment on basal and hCG-stimulated testosterone and cAMP accumulations were studied in primary culture of Leydig cells. Basal testosterone accumulation was significantly increased by a 24 h AVP-pretreatment of Leydig cells (P less than 0.001). This effect was potentiated by the phosphodiesterase inhibitor (MIX) and was concomitantly accompanied by a slight but significant increase in cAMP accumulation (P less than 0.01). AVP-pretreatment of the cells for 72 h had no effect on basal testosterone accumulation, but exerted a marked inhibitory effect on the hCG-stimulated testosterone accumulation (P less than 0.001). This reduction of testosterone accumulation occurred even in the presence of MIX and was not accompanied by any significant change of cAMP levels. We conclude from these data that AVP is capable of modulating steroidogenesis in Leydig cells through specific and functionally V1 receptor subtype and postulate that this effect may be part of an intratesticular paracrine/autocrine control mechanism.
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PMID:Modulation of mouse Leydig cell steroidogenesis through a specific arginine-vasopressin receptor. 245 54

We have examined the distribution pattern and the density of various neuropeptide, neurotransmitter and enzyme containing neurons in the rat medial septum and the nucleus of the diagonal band of Broca to assess their possible involvement in the septohippocampal, septocortical and septobulbar pathways. Immunohistochemical methods were combined with the retrograde transport of a protein-gold complex injected in the hippocampus, the cingulate cortex or the olfactory bulb. Cholinergic neurons were the most numerous. Galanin-positive neurons were about two or three times less numerous than cholinergic cells. Both these cell types had a similar location though the choline acetyl transferase-like immunoreactive cells extended more caudally in the horizontal limb of the nucleus of the diagonal band of Broca. Immunoreactive cells for other neuroactive substances were few (calcitonin gene-related peptide, luteinizing hormone releasing hormone. [Met]enkephalin-arg-gly-leu) or occasional (dynorphin B, vasoactive intestinal polypeptide, somatostatin, neurotensin, cholecystokinin, neuropeptide Y and substance P). No immunoreactive cells for bombesin, alpha atrial natriuretic factor, corticotropin releasing factor, 5-hydroxytryptamine, melanocyte stimulating hormone, oxytocin, prolactin, tyrosine hydroxylase or arg-vasopressin were present. Choline acetyltransferase- and galanin-like immunoreactive cells densely participate to septal efferents. Cholinergic neurons constituted the bulk of septal efferent neurons. Galanin-positive cells were 22% of septohippocampal, 8% of septocortical, and 9% of septobulbar neurons. Galanin containing septohippocampal neurons were found in the medial septum and the nucleus of the diagonal band of Broca; galanin-positive septobulbar and septocortical cells were limited to the nucleus of the diagonal band of Broca. Occasional double-labellings were noticed with some peptides other than galanin. Luteinizing hormone-releasing hormone, calcitonin gene-related peptide and enkephalin were the most often observed; some other projecting cells stained for vasoactive intestinal polypeptide or dynorphin B. Luteinizing hormone-releasing hormone, calcitonin gene-related peptide and enkephalin were observed in septohippocampal neurons; luteinizing hormone-releasing hormone and vasoactive intestinal peptide were observed in septocortical neurons and calcitonin gene-related peptide, luteinizing hormone-releasing hormone and dynorphin B were observed in septo-bulbar cells. These results show that, in addition to acetylcholine, galanin is a major cellular neuroactive substance in septal projections to the hippocampus, the cingulate cortex and the olfactory bulb. The presence of septal projecting neurons immunoreactive for other peptides shows that a variety of distinct peptides may also participate, but in a smaller number, to septal efferent pathways.
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PMID:Cholinergic and peptidergic projections from the medial septum and the nucleus of the diagonal band of Broca to dorsal hippocampus, cingulate cortex and olfactory bulb: a combined wheatgerm agglutinin-apohorseradish peroxidase-gold immunohistochemical study. 247 18

The purpose of the present study was to quantify the extent to which several peptides and serotonin coexist with substance P or somatostatin in selected lumbar dorsal root ganglia of the cat. The technique for the simultaneous visualization of two antigens by immunofluorescence was used to investigate the coexistence of neuropeptides in the lumbar dorsal root ganglia of colchicine-treated cats. Perikarya immunoreactive for calcitonin gene-related peptide, galanin, leu-enkephalin, somatostatin, and substance P were visualized in both the lumbar 5 and 6 dorsal root ganglia. In contrast, no immunoreactivity was observed for adipokinetic hormone, bombesin, dynorphin A, met-enkephalin, oxytocin, tyrosine hydroxylase, thyrotropin-releasing hormone, vasopressin, vasoactive intestinal peptide, or serotonin in either ganglion examined. Substance P coexisted with calcitonin-gene-related peptide, somatostatin, and leu-enkephalin. Somatostatin was colocalized with calcitonin gene-related peptide, leu-enkephalin, and substance P but coexisted with galanin minimally. The cell area of immunoreactive perikarya was also examined. Data concerning the cross-sectional area of immunoreactive cells indicated that somatostatin-immunoreactive perikarya were generally the largest population observed (up to approximately 6,000 microns2). Somatostatin and calcitonin gene-related peptide, as well as substance P and calcitonin gene-related peptide, coexisted in populations of cell bodies that had a smaller size (less than 2,000 microns2). These results suggest that certain peptides which coexist in the dorsal root ganglia may provide histochemical markers for functional groups of primary afferent neurons.
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PMID:Lumbar dorsal root ganglia of the cat: a quantitative study of peptide immunoreactivity and cell size. 247 1

The CNS cell groups that innervate the sympathoadrenal preganglionic neurons of rats were identified by a transneuronal viral cell body labeling technique combined with neurotransmitter immunohistochemistry. Pseudorabies virus was injected into the adrenal gland. This resulted in retrograde viral infections of the ipsilateral sympathetic preganglionic neurons (T4-T13) and caused retrograde transneuronal cell body infections in 5 areas of the brain: the caudal raphe nuclei, ventromedial medulla, rostral ventrolateral medulla, A5 cell group, and paraventricular hypothalamic nucleus (PVH). In the spinal cord, the segmental distribution of virally infected neurons was the same as the retrograde cell body labeling observed following Fluoro-gold injections in the adrenal gland except there was almost a 300% increase in the number of cells labeled and a shift in cell group distribution. These results imply there are local interneurons that regulate the sympathoadrenal preganglionic neurons. In the medulla oblongata, serotonin (5-HT)-, substance P (SP)-, thyrotropin-releasing hormone-, Met-enkephalin-, and somatostatin-immunoreactive neurons of the raphe pallidus and raphe obscurus nuclei and the ventromedial medulla were infected. In the ventromedial and rostral ventrolateral medulla, immunoreactive phenylethanolamine-N-methyltransferase, SP, neuropeptide Y, somatostatin, and enkephalin neurons were infected. The A5 noradrenergic cells were labeled, as were some somatostatin-immunoreactive neurons in this area. In the were infected. The A5 noradrenergic cells were labeled, as were some somatostatin-immunoreactive neurons in this area. In the hypothalamus, tyrosine hydroxylase- and SP-immunoreactive neurons of the dorsal parvocellular PVH were infected. Only a few immunoreactive vasopressin, oxytocin, Met-enkephalin, neurotensin, and somatostatin PVH neurons were labeled.
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PMID:CNS cell groups regulating the sympathetic outflow to adrenal gland as revealed by transneuronal cell body labeling with pseudorabies virus. 254 65

The substances stimulating the release of immunoreactive corticotropin-releasing factor from cultured human placental cells were investigated. Monolayer primary cultures of trophoblast cells from pregnant women at term were used. The immunoreactive corticotropin-releasing factor released in the culture medium eluted from high-performance liquid chromatography with the same retention time as human corticotropin-releasing factor. Norepinephrine and acetylcholine increased immunoreactive corticotropin-releasing factor release into the culture medium in a dose-related manner. Epinephrine was partially active, whereas dopamine and serotonin did not induce significant changes of immunoreactive corticotropin-releasing factor release from placental cultures. Angiotensin II, interleukin-1, oxytocin, and arginine-vasopressin also increased placental immunoreactive corticotropin-releasing factor release in a dose-related manner, whereas other peptides (vasoactive intestinal peptide, substance P, somatostatin, atrial natriuretic factor, interleukin-2) were ineffective. These results showed that several neurotransmitters and peptides stimulate the release of immunoreactive corticotropin-releasing factor from placental cells, suggesting their possible involvement in the physiologic regulation of placental immunoreactive corticotropin-releasing factor release during pregnancy and parturition.
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PMID:Neurotransmitters and peptides modulate the release of immunoreactive corticotropin-releasing factor from cultured human placental cells. 256 97

The molecular characteristics of the somatostatin (SRIF) receptor were investigated by covalently cross-linking [125I-Tyr11]SRIF to rat anterior pituitary membranes using three heterobifunctional cross-linking agents, N-5-azido-2-nitrobenzoyloxysuccinimide, N-hydroxysuccinimidyl-4-azidobenzoate, and N-succinimidyl-6-(4'-azido-2'-nitrophenylamino) hexanoate, and the homobifunctional agent disuccinimidyl suberate. Sodium dodecyl sulfate-gel electrophoresis followed by autoradiography revealed two SRIF-binding proteins with apparent mol wt (Mr) of 69,000 and 66,000 that were selectively labeled by the four cross-linking agents. When cross-linking was performed with N-5-azido-2-nitrobenzoyloxysuccinimide, both proteins migrated as a broad band centered at 68,000; however, with N-hydroxysuccinimidyl-4-azidobenzoate, the band was resolved into 69,000 and 66,000 Mr components. N-Succinimidyl-6-(4'-azido-2'-nitrophenylamino) hexanoate covalently labeled the 69,000 Mr protein and a minor species with a Mr of 45,000-47,000. Cross-linking with disuccinimidyl suberate labeled only the 66,000 Mr band. Labeling of both bands was specific, since affinity labeling with each of the four agents was abolished when 1 microM cyclic SRIF was included in the binding reaction. Binding of [125I-Tyr11]SRIF to membranes and labeling of the 69,000 and 66,000 Mr SRIF-binding species were similarly inhibited in a dose-dependent manner by unlabeled SRIF. Radiolabeling of both proteins was specifically displaced by 1 microM SRIF-28 and [D-Trp8,D-Cys14]SRIF, but not by oxytocin. Moreover, the extent of radiolabel incorporation into both components was dependent on the concentration of [125I-Tyr11]SRIF in the binding reaction. These results demonstrate the presence of two SRIF-binding proteins in rat anterior pituitary membranes that show characteristics of the SRIF receptor.
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PMID:Covalent labeling of the somatostatin receptor in rat anterior pituitary membranes. 256 43

The expression of 3 neuropeptide genes, vasopressin (AVP), oxytocin (OT) and somatostatin (SOM), was studied in the developing rat hypothalamus using Northern blot analysis combined with densitometric scanning. A unique profile of developmental expression was established for each of the 3 genes. SOM mRNA is detectable at embryonic day 14 and reaches 40% of the adult levels by embryonic day 18. By contrast, accumulation of AVP and OT mRNA is mainly a postnatal event. AVP mRNA, although detectable in the late embryo, rises gradually after birth and attains 40% of adult levels after the second postnatal week. Maturation of OT gene expression occurs even later and parallels AVP gene expression with a lag time of one week. Observed increases in mRNA levels are due to an upregulation of gene expression since they occur essentially following cessation of neuronal cell proliferation. The rise in AVP and OT mRNA accumulation coincides with the establishment of synaptic input to AVP and OT neurons. Expression of the SOM gene, by contrast, occurs prior to neuronal cell differentiation and points to a possible function of SOM in the embryonic brain.
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PMID:Ontogeny of hypothalamic vasopressin, oxytocin and somatostatin gene expression. 256 76

Intraperitoneal injection of 5 micrograms cholecystokinin octapeptide (CCK-8) into male rats deprived of food for 48 h produced a transient (less than 15 min) increase in plasma levels of CCK-8 but suppressed food intake for an extended period (45 min). Plasma concentrations of CCK-8 after i.p. injection of CCK-8 were raised to levels which were fairly comparable to those after feeding. Intracerebroventricular (i.c.v.) injection of the CCK antagonist proglumide (100 micrograms) reversed the effect of CCK-8 on food intake, while i.p. injection of proglumide (100 micrograms) did not have this effect. Feeding increased the plasma concentrations of somatostatin and gastrin but not of oxytocin, and somatostatin and oxytocin but not gastrin were released in response to i.p. injection of CCK-8. However, neither somatostatin nor oxytocin affected food intake, and their release in response to CCK-8 was unaffected by i.c.v. injection of proglumide. These results support the suggestion that CCK-8 is a physiological 'satiety' peptide, which can affect food intake in rats by mechanisms involving both peripheral and central CCK receptors.
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PMID:Plasma concentrations of cholecystokinin octapeptide and food intake in male rats treated with cholecystokinin octapeptide. 256 47

A complex pattern of interactions appears to exist between the immune and neuroendocrine systems. Recently, vasopressin, oxytocin and vasoactive intestinal peptide have been isolated from the thymus. Using a rat somatostatin antisense RNA probe we have demonstrated expression of the somatostatin gene in the rat thymus. Furthermore, we have shown that the levels of thymic somatostatin mRNA exhibit a bell-shaped response to dexamethasone administration. Lipocortin I and II antisense RNA probes have been used as a positive control for the effects of the dexamethasone. We would suggest that somatostatin acts in the thymus in a paracrine mode to modulate T lymphocyte development.
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PMID:Somatostatin gene expression in the thymus gland. 256 79

The effect of somatostatin (SRIH) on the release of oxytocin (OT) in response to hypoglycemia during insulin tolerance test (ITT) was studied in seven normal men. Subjects were injected intravenously with 0.15 U/kg insulin alone (control test) or together with SRIH (4.1 micrograms/min x 90 min), naloxone (10 mg in an IV bolus), or the combination of the two substances. Plasma OT concentrations rose significantly during ITT; the OT response was significantly reduced by the treatment with SRIH and increased in the presence of naloxone. When both SRIH and naloxone were given, the OT response to hypoglycemia did not differ from that observed in the control test. These findings provide evidence that the effect of hypoglycemia on plasma OT levels is sensitive to the inhibition by SRIH and by naloxone-sensitive endogenous opioids. Because naloxone reversed the inhibiting effects of SRIH, an involvement of opioid peptides in SRIH action might be supposed. Alternatively, SRIH and naloxone-sensitive opioids might produce their inhibiting effects on OT rise in response to hypoglycemia through independent pathways.
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PMID:Naloxone abolishes the inhibiting effect of somatostatin on the release of oxytocin evoked by insulin-induced hypoglycemia in humans. 256 58


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