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)

Continuous cell lines have been established from a variety of biopsy and postmortem species of tumor from patients with small-cell carcinoma of the lung (SCCL) and have been maintained over several years. The medium from the cultures has been assayed for peptide, glycoprotein, and steroid hormones. Significant amounts of 14 hormones including calcitonin, adrenocorticotropin (ACTH), parathormone, luteinizing hormone, chorionic gonadotropin, glucagon, growth hormone, somatostatin, prolactin, beta-endorpin, lipotropin, oxytocin-neurophysin, vasopressin-neurophysin, and estradiol have been demonstrated. Up to ten different hormones have been produced by a single cell line. Most produce ACTH and all evaluated so far produce estradiol. These studies indicate that cells from SCCL have a potential for producing a wide variety of hormones and that this characteristic can be maintained for prolonged periods of culture in vitro.
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PMID:Hormone production by cultures of small-cell carcinoma of the lung. 626 22

The brain contains a large variety and number of peptides some of which were known earlier as hypothalamic hormones (vasopressin, oxytocin, luteinizing hormone-releasing hormone, thyrotropin-releasing hormone, somatostatin) or as pituitary hormones (the family of opiomelanocortins), while others, not primarily known as hypothalamic or pituitary hormones, may also have endocrine effects (substance P, angiotensin II, neurotensin, bombesin, vasoactive intestinal peptide (VIP), gastrin-cholecystokinin, glucagon, carnosine, bradykinin). These peptides, which form a new class of putative neurotransmitters, are present early in brain development and show important sex differences in both their pattern of innervation and their effects. Their peripheral effects may include intrauterine growth of the placenta and fetus, the timing of birth, acceleration of the course of labour and responses to haemorrhage (redistribution of cardiac output and stimulation of blood cell formation). Endogenous peptides are probably involved in brain development, which may explain their general, permanent and sex-dependent effects when given in the period of rapid brain development. Although peptides might in the future be useful for stimulating recovery from retarded brain development, at present one should be aware of the potential dangers of their use in, for example, obstetrics.
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PMID:Development of peptidergic systems in the rat brain. 627 64

The intermittent reports concerning metabolic actions of neurohypophysial extracts or hormones encouraged us to study the effect of these substances on the function of the endocrine pancreas. A surprisingly small amount of neural lobe (NL) extract (0.025 NL eq/ml) stimulated a 425% increase in the release of glucagon from islets isolated from the pancreas of the rat. Gel filtration of the extract produced an elution profile of glucagon-releasing activity that was superimposable on the profiles of oxytocin (OT) and arginine vasopressin (AVP). Synthetic OT and AVP each elicited a concentration-dependent stimulation of glucagon release but failed to influence insulin release in medium 199 containing 5.6 mM glucose. They were effective at 0.2 ng/ml (+55%, +50%) and produced a striking increase (five- to sevenfold) at 20 ng/ml. The response to each peptide was greatly diminished in the presence of a higher concentration of glucose (11 mM). The lysine, desamino-, and 1,6-aminosuberyl analogues of vasopressin, vasotocin, and AVP are equipotent peptides, whereas the desglycinamide analogue, pressinoic acid, and angiotensin II were inactive. Injection of AVP (1 microgram iv) produced a rapid increase in peripheral glucagon (+185% in 5 min). The response to injection of OT was less rapid (+105% in 15 min), but in each case elevation of insulin was also observed. Our results provide evidence that OT and AVP can act directly on the endocrine pancreas and may help explain previous reports of metabolic actions of these peptides.
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PMID:Actions of neurohypophysial peptides on pancreatic hormone release. 636 29

In this study we have examined the effect of the administration of oxytocin on basal blood concentrations of insulin, glucagon, cortisol, growth hormone, and on the dynamic secretory response of these hormones to intravenous glucose administration (0.33 g/kg) in basal condition and after the injection of 3 IU (1 plus 2 IU/1 h) or 6 IU (2 plus 4 IU/1 h) of oxytocin (6 subjects for each group). The highest dose of oxytocin (6 IU) used significantly increased insulin secretion in response to intravenously administered glucose. No significant change of insulin secretion was observed with 3 IU of oxytocin. Glucagon, cortisol, and growth hormone response to intravenous injection of glucose was not affected by oxytocin (3 or 6 IU) administration. These results suggest that high doses of oxytocin affect beta-cell function in normal man.
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PMID:Effect of pharmacological doses of oxytocin on insulin response to glucose in normal man. 638 46

Recent neuroanatomical and behavioral evidence has indicated that vasopressin (VP) increases pain thresholds. In the present study intracerebroventricular (ICV) administration of both arginine VP (AVP: 75-500 ng) and 1-deamino-8-D-arginine vasopressin (DDAVP: 150-500 ng) elevated tail flick latencies. Oxytocin (OXY, ICV), also elevated tail-flick latencies (150-1000 ng); however this increase was accompanied by "barrel-roll" seizure activity. VP analgesia was eliminated by pretreatment with 1-deamino-penicillamine-2(O-methyl)tyrosine-AVP (dPTyr(me)AVP: 500 ng, ICV), a VP antagonist, but not naloxone (1 or 10 micrograms, ICV), suggesting that VP modulates nonciceptive thresholds through its own binding sites. Conversely, pretreatment with naloxone (1 micrograms, ICV) but not dPTyr(me)AVP (1 microgram, ICV) attenuated the analgesic efficacy of systemic morphine (10 mg/kg), further dissociating VP and central opiate analgesic processes. Finally, systemic pretreatment with dexamethasone potentiated VP analgesia. These data support the notion that VP is a specific non-opioid pain inhibitor.
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PMID:Vasopressin analgesia: specificity of action and non-opioid effects. 649 25

The contractile effects of lysine- (L) and arginine- (A) vasopressin (VP) on isolated non-pregnant myometrium and uterine arteries and the inhibition of these actions by two analogues of posterior pituitary hormones, deamino-ethyl-LVP (dE-LVP) and deamino-ethyl-oxytocin (dE-OXY) were investigated. Both AVP and LVP effectively stimulated the smooth muscle preparations. The threshold dose for both agonists was about 2 ng/ml of bath fluid and a maximal response was obtained with approximately 75 ng/ml. No distinguishable effect was produced by dE-LVP and dE-OXY alone, but when given before the agonists in concentrations of 150 or 300 ng/ml, dose-dependent inhibition of the contractions was seen. The inhibition of the uterine artery responses was always greater than the inhibition of the effects on myometrial activity and dE-LVP appeared to have stronger antagonistic effects than de-OXY on the myometrial responses to the agonists. The inhibition of the myometrial and uterine artery responses to AVP could explain the therapeutic effect of dE-OXY recently found in primary dysmenorrhoea, where increased VP secretion seems to be of aetiological importance.
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PMID:Vasopressin effects on isolated non-pregnant myometrium and uterine arteries and their inhibition by deamino-ethyl-lysine-vasopressin and deamino-ethyl-oxytocin. 688 6

Analysis of peptides by reverse-phase high-pressure liquid chromatography would be simplified if retention times could be predicted by summing the contribution to retention of each of the peptide's amino acid side chains. This paper describes the derivation of values ("retention coefficients") that represent the contribution to retention of each of the common amino acids and end groups. Peptide retention times were determined on a Bio-Rad "ODS" column at room temperature with a linear gradient from 0.1 M NaclO(4), pH 7.4 or 2.1, at 0 min to 60% acetonitrile/0.1 M NaclO(4) at 80 min. The NaclO(4), a chaotropic agent, was added to improve peak shape and to minimize conformational effects. Retention coefficients for the amino acids were computed by using a Hewlett-Packard 9815A calculator programmed to change the retention coefficients for all amino acids sequentially to obtain a maximum correlation between actual and predicted retention times. Correlations of 0.999 at pH 7.4 and 0.997 at pH 2.1 were obtained for 25 peptides including glucagon, oxytocin, [Met]enkephalin, neurotensin, and somatostatin. This high degree of correlation suggests that, for peptides containing up to 20 residues, retention is primarily due to partition processes that involve all the residues. Although steric or conformational factors do have some effect on retention, the data suggest that under the above chromatographic conditions the retention of peptides containing up to 20 residues can be predicted solely on the basis of their amino acid composition. This possibility was tested by using data taken from the literature.
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PMID:Prediction of peptide retention times in high-pressure liquid chromatography on the basis of amino acid composition. 692 13

The investigations were carried out on white rats determining the level and synthesis of acetylcholine (ACh) in the cerebral cortex, striatum, and in some experiments also in the brain stem. Thyroxine administered subcutaneously increased ACh synthesis in the cerbral cortex and reduced it in the striatum without changing the level of ACh in these structures. After thyroxine administration in vitro these changes were not observed. Intraperitoneal insulin caused no changes in the level and synthesis of ACh while in vitro ACh synthesis was increased in the cortex as well as striatum after insulin. Glucagon, hydrocortisone, adiuretin and oxytocin had no effect on ACh level and synthesis in the tested structures.
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PMID:Investigations on the effects of certain hormones on acetylcholine metabolism in the central nervous system. 700 85

Infusion of oxytocin (50--500 microU/kg/min) into normal conscious dogs produces a rise in plasma glucose, insulin, and glucagon levels. These changes are accompanied by a prompt increase in glucose production followed by an increase in overall glucose uptake, as determined using 6-3H-glucose infusion.
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PMID:Oxytocin infusion increases plasma insulin and glucagon levels and glucose production and uptake in the normal dog. 700 66

Previous studies have shown that a neutral metallo-endopeptidase purified from rat kidney degrades the B chain of insulin, glucagon, ACTH and, at a markedly slower rate, the A chain of insulin. In contrast the enzyme does not attack native insulin, oxytocin, vasopressin, ribonuclease, albumin or denatured hemoglobin. The current studies demonstrate that the neutral peptidase also degrades the isolated C-peptide of proinsulin and cleaves certain peptide bonds in and near the C-peptide moiety of native proinsulin. Time courses of the formation of fluorescamine-reactive material during digestion of proinsulin and isolated C-peptide with the peptidase were identical. However, structural analysis of the peptidase-digested proinsulin showed that the enzyme does not convert proinsulin to insulin but that the peptidase cleaves one bond, Tyr26-Thr27, in the B chain moiety and five bonds in the C-peptide moiety, producing four split proinsulins. One of the split proinsulins is des-octacosa-peptide (27-54) porcine proinsulin or des-tetracosapeptide (27-50) bovine proinsulin. Each is a derivative of the insulin molecule having an extension of nine residues (ten residues in the case of the derivative from bovine proinsulin) at the N-terminus of A chain and lacking four residues at the C-terminus of B chain. This two chain derivative retains full immunoreactivity with insulin antibodies and exhibits 2.4-times more biological activity (promotion of glycogenesis in primary cultured hepatocytes) than proinsulin and about two-thirds the activity of insulin.
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PMID:Degradation of proinsulin and isolated C-peptide by rat kidney neutral metallo-endopeptidase. 702 23


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