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)

Neuropeptides and biogenic amines known to be present in neurons or afferent terminals in the paraventricular nucleus (PVH), supraoptic nucleus (SON) and/or lateral hypothalamus (LH) were added to small areas of these structures obtained by micropuncture and cyclic adenosine monophosphate (cAMP) levels were measured. cAMP accumulation occurred in PVH, SON and LH in response to neuropeptides of the secretin family, such as vasoactive intestinal peptide (VIP) and in response to catecholamines. Bradykinin, alpha-melanocyte-stimulating (alpha-MSH), luteinizing hormone-releasing hormone (LH-RH), oxytocin and carbamylcholine stimulated cAMP accumulation selectively in one or two of the above structures. Glucagon, cholecystokinin (CCK), somatostatin (SRIF), corticotropin-releasing factor (CRF), thyrotropin-releasing hormone (TRH), adrenocorticotropin (ACTH), melanocyte-stimulating hormone (MSH), methionine enkephalin (Met-Enk), beta-endorphin, neurotensin, bombesin and angiotensin II did not effect cAMP levels while leucine enkephalin (Leu-Enk), arginine vasopressin and gamma-aminobutyric acid (GABA) elicited regionally selective decreases in basal levels of cAMP. When interactions between some of these compounds were measured, VIP and norepinephrine exerted a more than additive effect on cAMP elevation in the PVH, while the effect on cAMP of the SON and LH was additive.
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PMID:Interaction of neuropeptides and biogenic amines on cyclic adenosine monophosphate accumulation in hypothalamic nuclei. 300 57

In previous in Vitro and in Vivo studies oxytocin was shown to stimulate A and B cell secretion. In the present study we show that oxytocin is also able to increase arginine-induced glucagon and insulin secretion in healthy human beings. Similar results were obtained in both insulin-dependent (type-1) and non-insulin dependent (type-2) diabetic subjects.
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PMID:Oxytocin increases arginine-induced A and B cell secretion in normal man and in diabetic subjects. 304 83

Pharmacological doses of oxytocin administered in basal conditions evoked a rapid surge in plasma glucose and glucagon levels followed by a later increase in plasma insulin and adrenaline levels. The effects of oxytocin on plasma glucagon and adrenaline levels were potentiated by hypoglycemia. When the endogenous pancreas secretion was suppressed by cyclic somatostatin (150 micrograms/h) and exogenous glucagon (3.5 micrograms/h) and insulin (0.2 mU/kg.min) were both replaced, oxytocin (0.2 U/min) evoked a transient but significant increase in plasma glucose levels suppressing the glucose infusion rate (GIR) in the first 60 min. On the contrary at higher insulin infusion rate (0.6 mU/kg.min) plasma glucose levels and GIR remained unaffected throughout the study. Oxytocin seems also to potentiate glucose-induced insulin secretion as evidenced by hyperglycemic glucose clamp. In conclusion, pharmacological doses of oxytocin seem to exert a prevalent hyperglycemic effect by a combined action at the liver site (as glycogenolytic agent) and at the endocrine pancreas (as a stimulatory agent of A cell secretion).
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PMID:Pharmacological doses of oxytocin affect plasma hormone levels modulating glucose homeostasis in normal man. 306 8

Immunoreactive oxytocin and vasopressin were found in human and rat pancreatic extracts. The pancreatic oxytocin and vasopressin eluted on Sephadex G-75 gel filtration chromatography and on reverse phase high pressure liquid chromatography in the same positions as their respective reference preparations. The immunoreactive oxytocin was biologically active in the rat milk ejection assay. The presence of oxytocin and vasopressin in human and rat pancreatic extracts suggests the possibility of local synthesis of both hormones. The neurohypophysial hormones are known to be endocrine mediators of insulin and glucagon release. The finding of oxytocin and vasopressin in the pancreas raises the possibility, although yet unproven, of local synthesis and perhaps a paracrine function for the neurohypophysial peptides upon pancreatic hormone release or for a local function upon the liver.
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PMID:Oxytocin and vasopressin are present in human and rat pancreas. 319 25

1. Administration of 10 micrograms kg-1 of the long lasting potent kappa- and weaker mu-opioid agonist N-(cyclopropylmethyl)-19-isopentylnororvinol (M320) twice daily from day 20 of gestation prolonged the internal gestation period of the rat and retarded the development of the offspring in the perinatal period. 2. The capacities of myometrial, placental and cervical tissues to produce prostaglandin E2 (PGE2) were not affected by M320 treatment. 3. During the period in which parturition normally occurred in saline-treated rats, foetal pituitary levels of immunoreactive oxytocin (ir-OXY) but not immunoreactive arginine-vasopressin (ir-AVP) were greater in M320-compared to saline-treated animals. Following the completion of parturition, foetal pituitary ir-OXY and ir-AVP levels continued to rise in saline-treated rats, but fell dramatically in rats treated subacutely with M320. 4. These data indicate that subacute treatment with M320 may inhibit foetal oxytocin release at term. This foetal OXY release may be a stimulus for the initiation of labour.
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PMID:Studies of the effects of subacute treatment with N-(cyclopropylmethyl)-19-isopentylnororvinol (M320) on timing of parturition in the rat. 320 93

Experiments were done to provide a detailed map of the location and a description of morphological characteristics of vasopressin (AVP-IR)-, neurophysin II (NII-IR)- and oxytocin (OXY-IR)-immunoreactive neuronal perikarya in the forebrain of the cat. In addition, the location of cells in the forebrain retrogradely labeled following injections of tracers into the neurohypophysis was determined. The distribution of AVP-IR and NII-IR was similar in all cases studied. Most of the cells containing AVP-IR and OXY-IR were observed in the hypothalamic paraventricular (PVH) and supraoptic (SON) nuclei. In addition, AVP-IR and OXY-IR cell bodies were found in the regions of the nucleus of the diagonal band of Broca, the dorsal chiasmatic nucleus, the anterior hypothalamic-preoptic area, the periventricular area, the nucleus circularis, the perifornical area of the lateral hypothalamus, the accessory SON, the area of the tuber cinereum (Tca), and the medial nucleus of the amygdala. The density of AVP-IR cells was greater than that of OXY-IR cells in these regions. Several forebrain areas were also observed to contain only AVP-IR perikarya: the suprachiasmatic nucleus (Sc), the bed nucleus of the stria terminalis, and the region of the substantia innominata and ventral globus pallidus (SI/GP). In addition, the dorsomedial nucleus of the hypothalamus only contained OXY-IR perikarya. Most of the cells immunoreactive to AVP were multipolar and had spinelike processes over their somata and proximal dendrites. In addition, the majority of cells in the PVH and SON were round or oval, whereas those outside these nuclei were fusiform or triangular. The mean somal area of AVP-IR cells in the region of the SI/GP was significantly (P less than 0.05) larger than that of AVP-IR cells in all other regions examined, whereas the mean somal area of Sc AVP-IR cells was significantly (P less than 0.05) smaller than that of all other groups of AVP-IR cells examined. Most OXY-IR cells were similar morphologically to those immunoreactive to AVP, except that OXY-IR cell bodies and their appendages did not have spinelike processes. In addition, OXY-IR perikarya were generally of uniform size. OXY-IR cells in the PVH and accessory SON were significantly (P less than 0.05) larger than AVP-IR cells in the same regions, but were not different from AVP-IR cells in the lateral hypothalamus and SON.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Distribution and morphology of vasopressin-, neurophysin II-, and oxytocin-immunoreactive cell bodies in the forebrain of the cat. 329 31

Oxytocin is known to increase plasma levels of insulin, glucagon and glucose in dogs. Plasma levels of vasopressin rise during stressful conditions. Since vasopressin counteracts several oxytocin-induced effects, it was decided to study how vasopressin influences the oxytocin-induced elevation of plasma levels of insulin, glucagon and glucose. Therefore oxytocin at 0.11 (which gives rise to physiological plasma concentrations) was infused i.v. for 10 min into fasted, conscious dogs either alone or in combination with 0.033 or 0.17 nmol kg-1 h-1 of L-vasopressin. Accordingly, 1.1 nmol kg-1 h-1 of oxytocin was infused alone or in combination with 0.67 or 1.7 nmol kg-1 h-1 of L-vasopressin. Repeated blood samples were drawn during and after the infusions and insulin and glucagon levels were determined by radioimmunoassay. Plasma levels of insulin increased three- and six-fold in response to 0.11 and 1.1 nmol kg-1 h-1 of oxytocin, respectively, and the elevations were inhibited by L-vasopressin. Slight (1.5-fold) increases in plasma levels of glucagon were observed following 0.11 and 1.1 nmol kg-1 h-1 of oxytocin, although the effect was significant only after the latter dose. Concomitant infusion with L-vasopressin did not markedly influence the effect caused by oxytocin. Small, insignificant increases in blood glucose levels were induced by both doses of oxytocin. These effects were not affected by concomitant infusions of L-vasopressin. The insulin levels rose before glucose levels suggesting that oxytocin stimulates the release of insulin without a previous rise in glucose levels. In conclusion, it has been shown that vasopressin, in amounts which give rise to physiological plasma concentrations, inhibits oxytocin-induced effects on insulin levels, and that oxytocin stimulates the release of insulin via a mechanism which is independent of elevations in blood glucose levels.
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PMID:L-vasopressin inhibits oxytocin-induced increases of plasma levels of insulin conscious dogs. 329 61

Recent reports indicate that oxytocin exerts direct effects on the release of insulin and glucagon from the endocrine pancreas of the rat. The purpose of this study was to determine whether oxytocin-like immunoreactivity is present in the anglerfish islet, and if it is associated with subsets of hormone-producing cells. Antisera against oxytocin, insulin, glucagon, somatostatin, neuropeptide Y, and the 200-kd neurofilament polypeptide were applied to serial 5 micrometers sections of pancreatic islets. The antiserum to the 200-kd neurofilament polypeptide labeled nerve bundles and axons, some of which were also stained with the oxytocin antiserum. Oxytocin immunoreactivity was observed in large nerves that branched into varicose fibers. These fibers were consistently associated only with clusters of insulin-producing cells. Successive application of oxytocin and insulin antisera to the same section provided additional verification of this relationship. Oxytocin-labeled nerves were not associated with cells immunoreactive to glucagon, somatostatin, or neuropeptide Y (anglerfish peptide Yg). The results demonstrate that oxytocin or an oxytocin-like peptide is located in fibers that surround only insulin-producing cells in the anglerfish islet. Although the functional significance of this observation remains to be determined, the results imply that oxytocin, or an oxytocin-like peptide, may affect the synthesis or release of insulin from anglerfish islets.
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PMID:Oxytocin-like immunoreactive nerves are associated with insulin-containing cells in pancreatic islets of anglerfish (Lophius americanus). 330 46

This paper presents data showing that the sympathetic autonomic areas of the cat thoracolumbar spinal cord contain nerve terminals and fibres with immunoreactivity for at least seven neuropeptides. The distribution in the intermediolateral cell column of the terminals and fibres which contain enkephalin-, neuropeptide Y-, neurotensin-, substance P-, and neurophysin II-like immunoreactivity (ENK, NPY, NT, SP, and NP2, respectively) suggests that these peptides are involved in more generalized functions of the autonomic nervous system. On the other hand, peaks in density of immunoreactivity at certain levels suggest that different levels of influence of sympathetic preganglionic neurons by the various peptides may occur along the length of the thoracolumbar cord. The distribution of terminals and fibres containing somatostatin- and oxytocin-like immunoreactivity (SS and OXY) suggests that these peptides may be part of specific pathways to particular sympathetic preganglionic neurons. The possible sources of the terminals and fibres containing ENK, NPY, NT, SS, and SP include the spinal cord and supraspinal areas, whereas the source of these structures with OXY and NP2 is most likely supraspinal. The data suggest that coexistence of peptides and interactions between structures containing different neuropeptides occur in the spinal autonomic areas. It is speculated that neuropeptides have an important role to play in the regulation of the cardiovascular division of the autonomic nervous system.
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PMID:Peptidergic inputs to sympathetic preganglionic neurons. 331 10

The aim of the present investigation was to study changes in insulin, glucagon and plasma glucose levels in response to suckling in lactating dogs. Blood samples were drawn from a peripheral vein during suckling in weeks 1 and 3 of lactation in 10 lactating beagles. Insulin- and glucagon-like immunoreactivity (below referred to as insulin and glucagon) were determined by radio-immunoassay, and plasma glucose levels by the glucose oxidase method. Insulin and glucagon levels rose following onset of suckling. However, only the rises recorded in week 3 of lactation were statistically significant. Plasma glucose levels were not affected. The mechanism by which suckling influences the levels of insulin and glucagon is not known. However, the release of both hormones is under vagal control and it is possible that touching of the teats reflexly elicits a vagally mediated release of these hormones. Alternatively, since oxytocin stimulates the secretion of insulin and glucagon, the effects might be secondary to the oxytocin released by suckling. The physiological function of the suckling-related release of insulin may be to stimulate milk production. Furthermore, since glucagon is also released, each suckling period may be accompanied by a transfer of glucose to the mammary glands from other maternal stores.
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PMID:Suckling increases insulin and glucagon levels in peripheral venous blood of lactating dogs. 332 13


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