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)

The changes in plasma levels of arginine-vasopressin (AVP) and oxytocin (OXT) of rabbits by intraventricular administration of various drugs and their effects on the release of both hormones from the isolated posterior pituitary of rats were examined. An intraventricular injection of hypertonic saline, carbachol, angiotensin II, prostaglandin E2 or histamine to a rabbit increased the concentrations of plasma AVP and OXT, whereas serotonin decreased their plasma levels. Noradrenaline increased the concentration of OXT, but not that of AVP. Dopamine did not significantly affect the plasma level of either hormone. The release of AVP and OXT from the posterior pituitary fragments of rats was stimulated by changing the osmolality of the perfusion medium in vitro. Perfusion with medium containing dopamine suppressed the release of both hormones. However, the other bioactive amines and the drugs mentioned above did not affect the release of AVP and OXT.
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PMID:A study on the release mechanism of vasopressin and oxytocin. 323 19

Noradrenaline (NA) (1-100 microM) was applied to 41 neurons recorded intracellularly from the supraoptic nucleus (SON) of the rat hypothalamic slice preparation; 34 (83%) neurons showed membrane depolarization which was dose-dependent. The depolarization was frequently accompanied by decreased membrane resistance, increased firing rate and increased fluctuations in membrane potential. Following the application of the alpha-agonist, phenylephrine, 10 out of 11 neurons tested showed similar responses, while the beta-agonist, isoproterenol, caused no changes in 6 out of 7 SON cells. We found no difference in responsiveness between neurons having a 'phasic' or a 'non-phasic' pattern of firing. We conclude that NA depolarized and increased the firing rate of both vasopressin- and oxytocin-containing neurons through an action on alpha-adrenergic receptors.
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PMID:Depolarizing effect of noradrenaline on neurons of the rat supraoptic nucleus in vitro. 356 13

The frog urinary bladder undergoes, in some conditions, a marked increase of its water permeability when incubated in hypertonic media. This increase was observed with various nonpermeant solutes. It seems to result from the shrinkage of an osmo-sensitive compartment of the tissue, probably the epithelial cells. Many similarities were found between this effect and the physiological increase in water permeability (hydrosmotic response) elicited by antidiuretic hormone (ADH): both were dependent on the physiological state of the animals, and although the response was slower after hyperosmolar than after hormonal challenge, the patterns of response were similar, and in both cases markedly dependent on bathing solution temperature. Norepinephrine and prostaglandin E(1), which in this tissue reduce the hydrosmotic action of ADH, presumably by inhibiting the adenyl cylase also reduced the effect of hyperosmolarity. Conversely this effect was potentiated by incubation in the presence of oxytocin, exogenous cyclic AMP, and theophylline, conditions in which the intracellular concentration of cyclic AMP is increased. These data demonstrate that the response to hyperosmolarity is elicited, at least partly, by mechanisms also involved in the physiological hydrosmotic response to ADH.
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PMID:The effect of hypertonic media on water permeability of frog urinary bladder. Inhibition by catecholamines and prostaglandin E 1 . 434 37

Extracellular application of some peptides (oxytocin, Lys-vasopressin, Leu-enkephalin) to neuron RPal induced pacemaker potentials generation and initiated or increased bursting activity. Norepinephrine and prostaglandins E1 and E2 effects on neuron RPal electric activity were qualitatively similar to those produced by oxytocin and Lys-vasopressin. Dibutyryl-cAMP, papaverine (phosphodiesterase inhibitor) and sodium fluoride (nonspecific adenylate cyclase activator) induced or potentiated bursting activity. It is supposed that oxytocin, Lys-vasopressin, Leu-enkephalin, norepinephrine and E group prostaglandins effects are mediated by intracellular processes related to activation of adenylate cyclase and increase of cAMP level in the neuron.
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PMID:[Reactions of an identified edible snail neuron to application of peptides, mediators, prostaglandins, and cyclic nucleotides]. 611 55

The effects of Pro-Leu-GlyNH2 (PLG), administered i.c.v. in doses of 3.5, 35, 350 and 3500 pmol, were studied on the alpha-MPT-induced disappearance of catecholamines in microdissected rat brain nuclei. PLG, dose-dependently, increased dopamine disappearance in the nucleus caudatus and globus pallidus, whereas a decrease in dopamine disappearance was observed in the nucleus dorsomedialis. Noradrenaline disappearance was decreased in the medial septal nucleus, anterior hypothalamic area and lateral amygdala. A tendency towards an increase in noradrenaline disappearance was observed in the nucl. supraopticus. These data show that PLG has a central site of action. The effects of PLG on dopamine disappearance are comparable to those previously found with vasopressin, while the effects of PLG on noradrenaline utilization show a striking similarity with those previously obtained with oxytocin.
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PMID:Pro-Leu-GlyNH2 affects dopamine and noradrenaline utilization in rat limbic-forebrain nuclei. 615 Jul 49

The arterial blood flow distribution between tumour and intact renal tissue was investigated in rats with transplanted sarcomas. Changes in tissue flow were measured by the microsphere tracer technique, and the redistributing effects on blood flow of vasopressin, noradrenalin and oxytocin was recorded. Bolus injections of vasopressin gave a transient decrease of intact tissue flow, not found in tumours. At increasing doses of vasopressin and in early tumour growth phase, the flow discriminating effect tended to vanish. Constant intravenous infusion of vasopressin gave similar reduction of flow in tumour and intact tissue. Selective administration into the renal artery reduced flow in intact tissue but produced ambiguous effects in tumour tissue. Noradrenalin produced less reduction of tumour flow as compared with intact tissue flow. Oxytocin increased tumour blood flow while no flow change occurred in intact tissue. Oxytocin thus appeared to produce the most favourable redistribution of flow within tumour kidneys for the prospect of conveying cytotoxic agents selectively to the tumour.
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PMID:Effects of vasopressin, noradrenalin and oxytocin on blood flow distribution in rat kidney with neoplasm. 627 54

The effects of exogenous noradrenaline on the milk-ejection response were determined for nine Holstein cows. Noradrenaline was injected (0.95 nmol/kg) 15 s after the start of teat stimulation (preparation) or infused (0.13 nmol/kg per min, after bolus injection of 0.47 nmol/kg) starting 10 min before milking for 20 min. Cows were prepared (udder wash and dry) for 1 min before milking. Both injection and infusion resulted in approximately a 3.5-fold increase in peripheral noradrenaline at 1.75 min after the start of milking (baseline noradrenaline 0.83 and 0.89 nmol/l plasma; at 4 min, 2.00 and 3.00 nmol/l). Prolactin release was delayed and oxytocin release enhanced, while milk yield was decreased by 8.6% for both treatments. The maximum rate of milk flow was also depressed by treatment. In contrast, milking time increased for injection and decreased for infusion. In addition, a milk-yield-dependent change in the pattern of milk flow was seen in response to treatment. In medium-yield animals, two distinct milk-flow peaks were apparent and injection delayed the time to the second peak. We conclude that physiologically meaningful increases in peripheral noradrenaline can inhibit milk-ejection response by means of a peripheral mechanism not involving inhibition of release of oxytocin.
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PMID:Small increases in peripheral noradrenaline inhibit the milk-ejection response by means of a peripheral mechanism. 669 36

Estrogen-stimulated neurophysin (ESN) was determined by radioimmunoassay in three groups of patients with chronic renal failure: predialysis patients, patients on hemodialysis and patients on continuous ambulatory peritoneal dialysis. ESN levels were significantly elevated in all patients. ESN of these patients is undistinguishable from highly purified pituitary ESN. Immunological and physicochemical analyses of ESN in patients with renal failure suggest that the elevated plasma level is due to a failure of renal clearance. In addition, heterogeneity of urinary ESN, revealed by multiple immunoreactive peaks after gel filtration, indicates altered renal metabolism.
Nephron 1983
PMID:Estrogen-stimulated neurophysin in chronic renal failure. 683 53

In vivo microdialysis and retrodialysis were used to investigate the role of oxytocin (OXY) release in the mediobasal hypothalamus (MBH) of the ewe in the control of sexual receptivity. Initial experiments showed that OXY release was significantly increased in ovariectomized animals treated with progesterone and oestradiol when they were sexually receptive towards males and received intromissions. No such increases were seen during tests where the ewes were receptive but the males were prevented from achieving intromission. By contrast, OXY release was significantly reduced in tests where the ewes were not receptive to the male. In a second experiment artificial vaginocervical stimulation (VCS) was found to significantly increase OXY release when the animals were treated with oestradiol and this effect was potentiated by progesterone priming. OXY release in the MBH was not significantly altered by VCS in the presence of progesterone priming alone. Plasma OXY concentrations were significantly increased by VCS following all three hormone treatments but no one treatment was significantly more effective than another. Noradrenaline release in the MBH was only significantly increased following VCS when progesterone priming was given before oestradiol treatment. No effects of VCS on release of GABA, glutamate or dopamine were seen but their basal concentrations were significantly increased by the combined steroid treatment compared to oestradiol alone. In a third experiment it was found that OXY (10 microM) infused bilaterally into the MBH of receptive ewes, by retrodialysis, significantly decreased sexual receptivity and increased the release of noradrenaline and GABA.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:The role of oxytocin release in the mediobasal hypothalamus of the sheep in relation to female sexual receptivity. 809 40

It was found previously that the reduction of ovarian oxytocin (OT) content by up to 80% on d 12 and 16 of the cycle affects neither luteolysis nor estrous cycle duration in cattle. Because ovarian OT is suggested to be involved in progesterone synthesis/secretion, in the present study we wanted to investigate whether ovary depletion of OT in the early stages of the estrous cycle will influence the corpus luteum (CL) secretory function. In experiment 1, heifers (n = 15) had cannulae inserted into the aorta abdominalis through the coccygeal artery. The tip of each cannula was placed cranial to the origin of the ovarian artery. Noradrenaline (NA; 4 mg) was infused on d 5-10 for 30 min daily, evoking release of OT and lower, but evident, increases in the progesterone levels. This did not affect the length of the estrous cycle compared with control heifers infused with saline only. Because ovarian OT cannot be restored once discharged, NA served as a tool to deplete the CL of OT in experiment 2. The same dose of NA was given on d 5-10 to 4 heifers. The corpora lutea used to determine OT tissue concentrations were obtained by surgery under local anaesthesia 10-15 min after the last NA infusion. This dose of NA, depleted CL of OT by about 51% compared with control heifers. We conclude that significant reduction of ovarian OT content on d 5-10 does not affect the CL function. Thus, if ovarian OT is involved in ovarian steroidogenesis, it plays a modulatory rather than a mandatory role.
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PMID:Reduction of ovarian oxytocin content from early luteal phase does not affect the corpus luteum secretory function in cattle. 817 17


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