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)

Vasopressin (VP) potentiates the effect of corticotropin-releasing factor (CRF) on the secretion of adrenocorticotropic hormone (ACTH) from anterior pituitary cells in vitro, and both CRF and VP have been found in portal blood. These data support the hypothesis that VP acts synergistically with CRF to cause the secretion of ACTH in vivo but the origin of the CRF and VP, and the physiology of their release, have not been precisely defined. Parvocellular cell bodies in the paraventricular nucleus (PVN) which project to the external zone of the median eminence can be stained for both CRF and VP after adrenalectomy, and there is light microscopic immunocytochemical evidence that neurophysin (NP) may be located within some of the CRF-containing axons. Electron microscopic immunocytochemical studies have demonstrated the presence of CRF, VP and its 'carrier' protein, VP-associated neurophysin (NP-VP) in 100-nm neurosecretory vesicles (NSVs) in axons terminating near the portal capillary plexus in the external zone of the median eminence. If these peptides are extensively co-localized in the same NSVs in the median eminence, then coordinate secretion of CRF and VP in vivo is obligatory, at least in some physiological circumstances. We demonstrate in this report, using post-embedding electron microscopic immunocytochemistry on serial ultrathin sections, that CRF, VP and NP-VP are contained not only in the same axons and terminals, but in the same 100-nm NSVs in the median eminence of both normal and adrenalectomized rats. In addition, in the normal rat median eminence 44% of the CRF-positive axons and terminals stained strongly for VP and NP-VP, whereas in the adrenalectomized rat virtually all the CRF-positive structures in the median eminence showed strong staining for VP and NP-VP, indicating a transformation of one subpopulation of CRF-positive axons and terminals by adrenalectomy.
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PMID:Co-localization of corticotropin-releasing factor and vasopressin in median eminence neurosecretory vesicles. 390 Jul 40

Nausea was induced by having subjects smoke two high nicotine cigarettes in quick succession. Plasma levels of prolactin, adrenocorticotropic hormone, beta-endorphin/beta-lipotropin, growth hormone, arginine vasopressin, and neurophysin I increased without changes in thyroid stimulating hormone, luteinizing hormone, or follicle stimulating hormone. Nausea and pituitary hormone release correlated with high nicotine intake (smoking 2.87 mg nicotine cigarettes) but did not occur during lower nicotine intake (smoking 0.48 mg nicotine cigarettes). Individual differences in nausea and related hormonal responses may provide an objective method for predicting receptivity to smoking.
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PMID:Pituitary hormone response to cigarette smoking. 394 62

Short-latency emetic responses were induced in dogs by injecting angiotensin II (AII), arginine vasopressin (AVP), and neurotensin (NTN) into cerebroventricular (ICV) and cisternal (ICT) sites also responsive to the emetic effects of apomorphine (APO). Angiotensin III, bradykinin, bombesin, oxytocin, adrenocorticotropic hormone, substance P, gastrin-related peptide and cholecystokinin were ineffective. The results suggest a possible dopaminergic mediation of peptide-induced emesis by receptors in the area postrema (AP).
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PMID:Emetic effects of centrally administered angiotensin II, arginine vasopressin and neurotensin in the dog. 404 79

Protein carboxymethylase, an enzyme capable of methylating proteins and polypeptides, was purified from bovine pituitary. The anterior pituitary hormones, luteinizing hormone, follicle-stimulating hormone, adrenocorticotropic hormone, growth hormone, thyroid-stimulating hormone, and prolactin, were found to be substrates for this enzyme. The posterior pituitary hormones, oxytocin and vasopressin, did not serve as substrates. With luteinizing hormone as the substrate, protein carboxymethylase had a pH optimum near pH 5.5. A limiting K(m) of 1.47 muM for S-adenosyl-L-methionine was obtained with luteinizing hormone as the methyl acceptor. Possible roles of this enzyme in the posterior and anterior pituitary are discussed.
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PMID:Characterization and substrate specificity of a protein carboxymethylase in the pituitary gland. 436 60

Although the ovarian production of sex steroids is of obvious physiological importance, recent studies suggest that peptides such as oxytocin, relaxin and inhibin are also synthesized in the ovary. We report here the presence of immunoreactive (ir) beta-endorphin, ir-adrenocorticotropic hormone (ACTH) and presumptive high molecular weight forms of both in extracts of sheep ovary, consistent with ovarian production from a common precursor. Our findings suggest that beta-endorphin and ACTH are produced and secreted by the follicular cells, and that their production may be related to the oestrous cycle.
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PMID:Immunoreactive beta-endorphin in sheep ovary. 630 36

The present study explored neuropeptide responses to nicotine from smoking. Habitual smokers smoked research cigarettes of known strength under controlled laboratory conditions while blood samples were withdrawn unobtrusively for subsequent biochemical analysis. To provide a metric that reflected total nicotine intake and total neurohormonal output, data were integrated over time. Subjects were relatively unresponsive in the low-nicotine (0.48 mg) condition. In the high-nicotine (2.87 mg) condition, there were significant positive correlations between integrated plasma nicotine and plasma arginine vasopressin (r = +0.985), its carrier protein neurophysin I (r = +0.944), and beta-endorphin-beta-lipotropin (r = +0.977), but not adrenocorticotropic hormone. Data from an experiment that used an extraction step to remove beta-lipotropin corroborated the functional relationship between plasma nicotine and beta-endorphin implied by the original findings. Taking into account recent research on the role of neuropeptides in the modulation of affective states and cognitive function as well as of other CNS activity, the present findings were interpreted as strengthening the hypothesis that nicotine-stimulated neuropeptide release provides positive reinforcement for smoking.
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PMID:Neuroendocrine reactivity to nicotine in smokers. 631 18

To clarify the anatomical organization that allows for the synergy of vasopressin and oxytocin with corticotropin-releasing factor (CRF) in promoting adrenocorticotropic hormone secretion from the anterior pituitary, immunohistochemical double staining methods were used to compare the distribution of these peptides in the hypothalamic paraventricular nucleus of normal, colchicine-treated, and adrenalectomized male rats. In untreated animals, a few CRF-stained cells were found in the parvocellular division of the paraventricular nucleus, while brightly stained oxytocin- and vasopressin-immunoreactive cells were centered in the magnocellular division. In animals treated with colchicine, and inhibitor of axonal transport, large numbers of CRF-stained cells were found in the parvocellular division of the nucleus, and 1-2% of these also stained with antivasopressin. As reported previously, a substantial number of oxytocin-stained cells, centered in a discrete anterior part of the magnocellular division, also expressed CRF immunoreactivity. In contrast, after adrenalectomy, CRF immunostaining of cells in the parvocellular division was enhanced selectively and greater than 70% of these cells also stained positively for vasopressin. The distribution of oxytocin-stained cells was not influenced by adrenalectomy. The unusual localization of vasopressin immunoreactivity in parvocellular neurosecretory neurons in the adrenalectomized rat suggests that a single population of cells can produce CRF and vasopressin, both of which are potent promoters of adrenocorticotropic hormone secretion. These findings indicate that there is a state-dependent plasticity in the expression of biologically active peptides by individual neuroendocrine neurons.
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PMID:Co-expression of corticotropin-releasing factor and vasopressin immunoreactivity in parvocellular neurosecretory neurons of the adrenalectomized rat. 636 32

The development of two monoclonal antibodies for use as second antibodies in immunocytochemistry is described. The antibodies are produced by mouse X mouse hybrid myelomas, and are both of the IgG type. The two antibodies, RB23 and ND13, were used to detect neurophysin by three-step peroxidase-antiperoxidase (PAP) immunostaining, and were "internally labeled" with 3H-lysine for the radioimmunocytochemical localization of neurophysin, substance P, and tyrosine hydroxylase using rabbit first antibodies. The binding sites of RB23 and ND13 on the rabbit IgG antibodies were determined by solid-phase radioimmunoassay, using allotype-specific rabbit serum to compete with RB23 and ND13. It was found that both RB23 and ND13 are directed against the B4 kappa-light-chain allotype. The immunocytochemical localization of adrenocorticotropic hormone and somatostatin with rabbit primary antibodies was not achieved with RB23 or ND13, and it is proposed that these antibodies are not of the B4 allotype. The findings demonstrate that monoclonal second antibodies can be useful general reagents for conventional immunocytochemistry as well as for radioimmunocytochemistry. Furthermore, allotype-specific monoclonal second antibodies may prove useful in the simultaneous immunohistochemical localization of more than one antigen in a given tissue section.
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PMID:Immunocytochemistry with monoclonal anti-immunoglobulin as a developing reagent: application to immunoperoxidase staining and radioimmunocytochemistry. 641 91

Arginine vasopressin modulates the release of adrenocorticotropic hormone, beta-endorphin, and prolactin from the anterior pituitary. Release is mediated by the V1b receptor through the mobilization of intracellular Ca2+ by phosphatidylinositol hydrolysis. In contrast to its well characterized peripheral actions, such as antidiuresis, contraction of vascular smooth muscle, and stimulation of hepatic glycogenolysis, the exact site and mechanism of vasopressin action in the pituitary remain unclear. This is largely due to a lack of information on the molecular identity and exact localization of the V1b receptor. This lack prompted us to try to isolate this receptor subtype. Here we report the molecular cloning and functional expression of a complementary DNA encoding the human V1b receptor. The deduced 424-amino acid sequence of the receptor has highest overall homology with the V1a, V2, and oxytocin receptors, with homologies of 45, 39, and 45%, respectively. The receptor expressed in COS-1 cells has a single binding site for arginine vasopressin with a Kd of 0.17 +/- 0.04 nM. It binds various agonists and antagonists of vasopressin with affinities distinct from those of V1a and V2 receptors but consistent with those anticipated for the V1b receptor on the basis of the pharmacological studies. Furthermore, arginine vasopressin evoked calcium-dependent chloride current in Xenopus oocytes transfected with the receptor, which was not affected by a V1a/V2 antagonist. In contrast, the current evoked in oocytes transfected with V1a receptor was abolished by the antagonist. Northern blot analysis revealed that the receptor expression is restricted to the pituitary. These data clearly indicate that the cloned cDNA encodes the V1b receptor.
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PMID:Molecular cloning and functional expression of a cDNA encoding the human V1b vasopressin receptor. 792 52

The present study had two objectives: (1) to provide information on neuroendocrine challenge tests that can lead to diagnostic tests in humans; and (2) to confirm our previous observation that chronic fluoxetine selectively inhibits serotonin (5-HT1A) receptor function. We determined the effect of chronic fluoxetine and desipramine (DMI) on the hormone response to ipsapirone, a 5-HT1A agonist and a potential anxiolytic drug. Ipsapirone increased oxytocin, adrenocorticotropic hormone (ACTH), corticosterone, and prolactin, but not renin or vasopressin concentrations in plasma. Chronic fluoxetine, but not DMI, significantly inhibited the effect of ipsapirone on plasma oxytocin, ACTH and corticosterone concentrations. Chronic fluoxetine also reduced the Bmax for 3H-8-hydroxy-2-(dipropylamino) tetralin (3H-8-OH-DPAT) labelled 5-HT1A receptors in the midbrain. Neither antidepressant altered the density or affinity of 5-HT uptake sites. In conclusion, the present results confirm our previous results using 8-OH-DPAT as a challenge, and suggest that chronic 5-HT uptake inhibition results in adaptive changes leading to decreased function of the 5-HT1A receptor system. Finally, because ipsapirone may be administered to humans, it might be usable to evaluate 5-HT1A receptor function in depressed patients.
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PMID:Attenuation of hormone responses to the 5-HT1A agonist ipsapirone by long-term treatment with fluoxetine, but not desipramine, in male rats. 799 56


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