Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01275 (glucagon)
 26,492 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Infusion of oxytocin into normal dogs increases plasma levels of insulin and glucagon and glucose production and uptake. To determine whether infused oxytocin also increases glucagon secretion from extrapancreatic sites, pancreatectomized dogs, off insulin for 18 hr, were infused with oxytocin and plasma glucagon, and glucose production and uptake were measured using the [6-3H]glucose primer-infusion technique. The diabetic dogs, in the control period, had elevated plasma glucose and glucagon levels, an increased rate of glucose production, and a relative decrease in glucose uptake (decreased clearance). Infusion of oxytocin (500 microU/kg/min) caused a rise in plasma glucagon and glucose levels, increased glucose production, and further decreased glucose clearance. It is concluded that oxytocin can stimulate secretion of extrapancreatic glucagon, which contributes to the increased glucose production.
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PMID:Oxytocin increases extrapancreatic glucagon secretion and glucose production in pancreatectomized dogs. 351 51

Corticotropin-releasing factor (CRF), a 41 amino acid polypeptide, has been isolated from ovine hypothalamic extracts, sequenced, and synthesized. It has a high potency for stimulating the secretion of corticotropin-like and beta-endorphin-like immunoactive substances in vitro and in vivo in laboratory animals and humans. The high concentration of CRF-like immunoactivity in hypophyseal portal plasma supports the hypothesis that CRF is the physiological hypothalamic factor. Human and rat CRF (rCRF) also have been purified and synthesized. They have an 83% sequence homology with ovine CRF (oCRF). oCRF-like activity has been found in human hypothalamus, pituitary stalk, posterior pituitary, thalamus, cerebral cortex, cerebellum, pons, medulla oblongata, spinal cord and in the adrenal, lung, liver, stomach, duodenum and pancreas. oCRF-like activity also has been found in the human placenta and in tissues producing ectopic ACTH. The action of CRF can be potentiated by vasopressin, oxytocin, epinephrine, norepinephrine, VIP, and angiotensin II. Intracerebroventricular administration of CRF in the rat produces prolonged elevations of plasma epinephrine, norepinephrine, glucose and glucagon; elevates mean arterial pressure and heart rate; increases motor activity and exploration in familiar surroundings and oxygen consumption; and decreases feeding and sexual behavior. Testing with CRF has enabled the separation of patients with hypothalamic and pituitary adrenal insufficiency. The CRF stimulation test has been useful in distinguishing pituitary from ectopic causes of Cushing's disease. The distribution of CRF within and beyond the hypothalamus provides an anatomical context for the observation that CRF can simultaneously activate and coordinate metabolic, circulatory and behavioral responses that are adaptative in 'stressful' situations. CRF not only stimulates the pituitary-adrenal axis in man, but it also influences several aspects of CNS function which may be of relevance to psychiatric illnesses.
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PMID:Corticotropin-releasing factor (CRF)--a review. 353 10

Conscious adult male rats bearing jugular cannulae were injected with either normal rabbit serum (NRS) or with serum containing antibodies to both oxytocin (OT) and arginine vasopressin (AVP). In the NRS-treated group, plasma levels of OT, AVP and immunoreactive glucagon (IRG) were significantly elevated 10 min after hemorrhage (2.3 ml/100 g body weight over 5 min) whereas hyperglucagonemia was not detected in the antiserum-treated group until 30 min posthemorrhage. In animals which were deprived of water during the experiment, plasma IRG in the antiserum-treated group reached only 40% of the levels in the NRS-treated controls. These results suggest that hemorrhage-induced elevations in circulating AVP and/or OT contribute to increased release of glucagon by the endocrine pancreas consistent with previous demonstration of glucagonotropic activity of synthetic neurohypophysial peptides.
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PMID:Evidence for participation of the neurohypophysial hormones in the hyperglucagonemic response to hemorrhage in the rat. 390 36

Peptides and non-peptides acting as vasoconstrictors or vasodilators have been tested in dog isolated carotid arteries with and without endothelium and in the presence and absence of a variety of antagonists and inhibitors of endogenous substances. It has been found that substance P and several other tachykinins, bradykinin, neurotensin, bombesin and acetylcholine relax the isolated artery only when the endothelium is present, while VIP, isopropylnoradrenaline, adenosine, histamine, prostaglandins E1 and E2, glucagon and insulin relax and angiotensin, vasopressin, oxytocin, 5-HT and noradrenaline contract the isolated vessel, no matter whether the endothelium is present or not. Peptide and non-peptide antagonists have been used with success to show that vasoconstrictors and vasodilators act on specific receptors, since their effects are reduced in the presence of antagonists, specific for one or another of the various agents. Inhibitors of the arachidonic acid cascade only reduce the effect of acetylcholine, suggesting that at least two different mechanisms are involved in the endothelium-mediated relaxation of arterial smooth muscles to peptide and non-peptide agents. The results summarised in this paper suggest that the site of action of several vasodilators is the endothelium, while other vasodilators and all the vasoconstrictors influence the arterial vessels tone presumably by acting on the smooth muscle cells.
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PMID:Effects of peptides and non-peptides on isolated arterial smooth muscles: role of endothelium. 393 Feb 67

Three analogues of posterior pituitary hormones, 1-deamino-2-D-Tyr(OEt)-4-Val-8-Orn-vasotocin(dE-VVT), 1-deamino-2-D-Tyr(OEt)-4-Thr-8-Orn-vasotocin(dE-TVT) and 1-deamino-2-D-Tyr(OEt)-oxytocin(dE-OXY) were compared for their inhibitory effects on vasopressin (VP)-induced uterine activity in healthy women. At menstruation, during recording of intrauterine pressure (18 recording sessions in 11 women), intravenous infusion of lysine vasopressin (LVP, 1 ng/min/kg/body weight) induced an increase of the uterine activity and dysmenorrhoea-like symptoms. Intravenous injections of all analogues (10 micrograms/kg body weight) caused relief of symptoms and inhibition of uterine activity, dE-TVT was the most effective and dE-OXY was least active. With dE-TVT almost complete inhibition of contractions was seen during the first 10 min after injection. The duration of effect was also greatest with that analogue (40-50 min). Only dE-OXY had an agonist effect on spontaneous uterine activity. Pharmacokinetic studies of intravenous dE-TVT (10 ng/kg body weight) showed that the plasma half-life was approximately 16 min and the clearance 30 l/h. The bioavailability of 100 ng/kg given intranasally was about 5.5%. Further studies are recommended.
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PMID:Vasotocin analogues which competitively inhibit vasopressin stimulated uterine activity in healthy women. 394 2

The survival of adult rat hepatocytes in monolayer culture was studied in the presence of different hormones (neurotensin, oxytocin, thyrotropin releasing hormone, luteinizing hormone releasing hormone, cholecalciferol, bradykinin, substance P, aldosterone, melanocyte stimulating hormone, 3,3',5-triiodo-1-thyronine, corticosterone, human growth hormone, glucagon, insulin, progesterone, testosterone, estradiol, and dexamethasone phosphate) or growth factors (fetal bovine serum). For this purpose trypan blue exclusion, lactate dehydrogenase, and DNA and protein content were measured at 24 and 72 h of culture. 10(-7) M Dexamethasone, a mixture of eight hormones, 10% fetal bovine serum, and a combination of the latter two supplements caused a more than 64% higher DNA content at 72 h when compared to control cultures. A striking agreement of these results with changes of lactate dehydrogenase leakage was observed, whereas trypan blue exclusion gave erratic results. Considerable changes of cell arrangement apparently specific for each supplement were observed by low magnification microscopy. It is concluded that glucocorticoids and fetal bovine serum have an outstanding effect on cell viability and that DNA or protein content or both are reliable indicators of cell viability in amitotic cultures.
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PMID:Influence of hormones and growth factors on viability, DNA, and protein content of adult hepatocytes in primary culture. 405 11

A possible role for adenylcyclase in insulin secretion was investigated. Isoproterenol, a predominantly beta-adrenergic agent, when mixed with an alpha-adrenergic blocking agent (phenoxybenzamine), stimulated insulin secretion from pieces of the rat's pancreas in vitro. Theophylline, caffeine, 3'5'-cyclic AMP, glucagon, adrenocorticotropin (ACTH), and thyrotropin (TSH), all of which are thought to act through the adenylcyclase systems in the liver and adipose tissue, also stimulated insulin secretion in vitro; oxytocin and vasopressin, which do not stimulate lipolysis in adipose tissue, were inactive. In all cases, stimulation of insulin secretion could not be detected when glucose was absent or present in only low concentrations (less than 100 mg/100 ml) and was maximal at high levels of glucose (300 mg/100 ml). When pancreatic tissue was obtained from normoglycemic rats and contained no detectable glycogen in the Islets, the stimulant effects of glucose and of theophylline were reduced or abolished by mannoheptulose and 2-deoxyglucose. When tissue was derived from rats infused for 8-10 hr with glucose and contained glycogen, theophylline, even in the absence of glucose, stimulated secretion and this effect was reduced by 2-deoxyglucose but not by mannoheptulose. It is suggested that the beta-cell contains an adenylcyclase system through which phosphorylase and possibly phosphofructokinase could be activated; and that insulin secretion could depend upon and be regulated by hormones and other substances which influence the rate at which glycolysis proceeds within the beta-cell.
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PMID:A possible role for the adenylcyclase system in insulin secretion. 429 54

1. The epigastric adipose tissue of rabbits has been prepared so that the effects of close arterial injections and infusions on blood flow and release of free fatty acids (FFA) can be studied. The effects of pharmacologically active agents and hormone preparations have been investigated.2. Release of FFA was stimulated by synthetic adrenocorticotrophic hormone (ACTH), alpha and beta melanophore stimulating hormone (MSH), porcine growth hormone, glucagon, thyrotropic hormone (TSH) and luteotropic hormone (LTH). Single injections of fat-mobilizing agents produce a sustained rise in the release of FFA.3. Although pitressin caused release of FFA, synthetic vasopressin and oxytocin failed to do so. The FFA releasing activity of pitressin has therefore been attributed to a contaminant.4. Catecholamines were found not to stimulate release of FFA from this fat depot, but were found to increase plasma FFA when infused intravenously.5. Injections of acetylcholine, histamine, bradykinin, 5-hydroxytryptamine, synthetic arginine vasopressin, and lysine vasopressin, oxytocin, angiotensin and FSH did not stimulate release of FFA although marked effects on blood flow were produced.6. Injections of prostaglandin E(1) gave sustained increases in blood flow, and inhibited FFA release when stimulated by growth hormone.7. The mobilization of FFA is sometimes associated with an increased rate of blood flow.
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PMID:The mobilization of free fatty acids from rabbit adipose tissue in situ. 430 78

The widespread occurrence of opioid peptides and their receptors in brain and periphery correlates with a variety of actions elicited by opioid agonists and antagonists on hormone secretion. Opioid actions on pituitary and pancreatic peptides are summarized in Table 1. In rats opioids stimulate ACTH and corticosterone secretion while an inhibition of ACTH and cortisol levels was observed in man. In both species, naloxone, an opiate antagonist, stimulates the release of ACTH suggesting a tonic suppression by endogenous opioids. In rats, a different stimulatory pathway must be assumed through which opiates can stimulate secretion of ACTH. Both types of action are probably mediated within the hypothalamus. LH is decreased by opioid agonists in many adult species while opiate antagonists elicit stimulatory effects, both apparently by modulating LHRH release. A tonic, and in females, a cyclic opioid control appears to participate in the regulation of gonadotropin secretion. Exogenous opiates potently stimulate PRL and GH secretion in many species. Opiate antagonists did not affect PRL or GH levels indicating absence of opioid control under basal conditions, while a decrease of both hormones by antagonists was seen after stimulation in particular situations. In rats, opiate antagonists decreased basal and stress-induced secretion of PRL. Data regarding TSH are quite contradictory. Both inhibitory and stimulatory effects have been described. Oxytocin and vasopressin release were inhibited by opioids at the posterior pituitary level. There is good evidence for an opioid inhibition of suckling-induced oxytocin release. Opioids also seem to play a role in the regulation of vasopressin under some conditions of water balance. The pancreatic hormones insulin and glucagon are elevated by opioids apparently by an action at the islet cells. Somatostatin, on the contrary, was inhibited. An effect of naloxone on pancreatic hormone release was observed after meals which contain opiate active substance. Whether opioids play a physiologic role in glucose homeostasis remains to be elucidated.
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PMID:Endocrine actions of opioids. 608 80

Specific SRIF(1-14) fragments were synthetized on resin using conventional procedures. Rabbits received subcutaneously peptidyl resins in complete Freund adjuvant emulsion. The presence of antibodies was assessed by immunocytochemical and radioimmunological assays. 1. Peptidyl resins lead to antibodies production; their specificity depends on sequence and molecular configuration of the peptide on the resin. Anti-resin antibodies were not detected. 2. In the brain, SRIF(1-4) (in rat) and SRIF(10-13) (in garden-dormouse) can be demonstrated in neurophysins--positive cells of both paraventricular and supraoptic nucleus, but never in hypothalamic or extrahypothalamic SRIF(1-14)--positive neurophysin negative cells. 3. Endocrine cells of pancreatic islets contain SRIF(6-9) (in man) or SRIF(10-13) (in rat, mouse, garden-dormouse); generally, these cells are not detected by SRIF(1-14) anti-serum. Moreover, SRIF(10-13) positive cells are also detected by specific glucagon antibodies. However, it cannot be concluded that SRIF(10-13) antibodies reveal the common Thr-Phe-Thr-Ser fragment in the entire glucagon molecule. It is postulated that antibodies to several SRIF tetrapeptides reveal molecular fragments provided by the functional cleavage of an hypothetical prohormone or by the inactivation of SRIF(1-14) molecule in target cells.
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PMID:[Preparation of antisera against some sequences of somatostatin synthetized on resin. Application to the immunological detection of somatostatin systems: preliminary results (author's transl)]. 612 35


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