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 effect of apomorphine (80 micrograms/kg s.c.) and oxytocin (30 ng i.c.v.) on penile erection and yawning was studied in intact and castrated male rats. In castrated rats both apomorphine and oxytocin responses were abolished. In these animals, testosterone (100 microgramS/kg s.c. once a day for 3 days), restored penile erection while estradiol benzoate (10 micrograms/kg s.c. once a day for 3 days) restored yawning induced by both compounds. 5-Dihydrotestosterone (DHT) or progesterone (each at a dose of 100 micrograms/kg s.c. once a day for 3 days) were ineffective. Given together, estradiol benzoate and DHT partially restored apomorphine- and oxytocin-induced yawning and penile erection, whereas estradiol benzoate and progesterone restored only yawning. Estradiol benzoate-induced recovery of yawning was prevented by the antiestrogen tamoxifen (1 mg/kg s.c. once a day for 3 days). In intact rats, progesterone increased and estradiol benzoate decreased apomorphine- and oxytocin-induced yawning without modifying penile erection, although oxytocin-induced yawning was prevented much less by estradiol benzoate than that induced by apomorphine. Testosterone or DHT were ineffective on both responses. Estradiol benzoate inhibition of apomorphine- and oxytocin-induced yawning was prevented by tamoxifen, which per se failed to modify apomorphine and oxytocin responses, as well as by testosterone or progesterone. The present results suggest that apomorphine- and oxytocin-induced penile erection and yawning are endocrine-dependent and differentially modulated by sexual steroids, suggesting that the mechanisms controlling the two behaviors are different even though they are often associated.
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PMID:Apomorphine-and oxytocin-induced penile erection and yawning in intact and castrated male rats: effect of sexual steroids. 820 15

This study tested the effect of brain serotonin (5-HT) depletion on the secretion of oxytocin (OT), vasopressin (VP), and adrenocorticotropin (ACTH) due to an osmotic load. The 5-HT neurotoxin 5,7-dihydroxytryptamine (5,7-DHT) was used to deplete brain 5-HT. The OT, VP, and ACTH osmotic sensitivity (slope of delta[OT]/delta[Osm]) and the osmotic threshold (X intercept of delta[OT]/delta[Osm]) were evaluated. Depletion of brain 5-HT decreased the OT osmotic sensitivity by > 80% (p < 0.001) without changing the OT osmotic threshold. Brain 5-HT depletion had no effect on the VP osmotic sensitivity and increased the VP osmotic threshold from 287.8 +/- 1.5 to 293.1 +/- 2.0 mOsm/kg (p < 0.05). The plasma ACTH increase due to infusion of hypertonic saline was not affected by brain 5-HT depletion. Brain 5-HT depletion significantly (p < 0.01) decreased the pituitary content of OT and VP by 38 and 32%, respectively, without changing ACTH content. These results provide evidence for a functional role of serotonergic neurons in osmoregulation of plasma and pituitary concentration of OT and VP, but not ACTH.
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PMID:The role of serotonergic neurons in intravenous hypertonic saline-induced secretion of vasopressin, oxytocin, and ACTH. 822 Nov 54

In the present study, we examined denervation-induced changes in the sensitivity of hypothalamic postsynaptic serotonin1A (5-HT1A) receptor function with respect to changes in the dose-dependent elevation in plasma hormones [adrenocorticotropic hormone (ACTH), corticosterone, prolactin, oxytocin, prolactin, renin and vasopressin] by the 5-HT1A agonist 8-hydroxy-2-(dipropylamino)tetralin (8-OH-DPAT). Rats received intracerebroventricular (i.c.v.) injections of the serotonin neurotoxin 5,7-dihydroxytryptamine (5,7-DHT) or vehicle (0.1% ascorbate in saline) 3 weeks before challenge with increasing doses of 8-OH-DPAT (0, 10, 50 or 200 micrograms/kg s.c.). The effectiveness of 5,7-DHT-induced destruction of serotonergic neurons was confirmed by a 93% reduction in [3H]paroxetine-labeled 5-HT uptake sites in the hypothalamus. No changes in basal levels of ACTH, corticosterone, oxytocin, prolactin, renin and vasopressin were observed in rats that received i.c.v. 5,7-DHT injections. The dose-response curves for 8-OH-DPAT-induced elevations of plasma corticosterone and prolactin levels were shifted to the left in rats treated with 5,7-DHT, whereas no significant difference in the ACTH dose-response curve was observed between rats treated with vehicle and rats treated with 5,7-DHT. In contrast, the maximal oxytocin response to 8-OH-DPAT was attenuated in rats treated with 5,7-DHT. A 5,7-DHT-induced decline in the synthesis of oxytocin could explain this phenomenon. Although 8-OH-DPAT did not increase plasma levels of renin or vasopressin in rats treated with vehicle, 8-OH-DPAT produced an elevation (75%) in plasma renin concentration but not in vasopressin levels in rats that received i.c.v. injections of 5,7-DHT. No change was observed in [3H]8-OH-DPAT labeled 5-HT1A receptors in the hypothalamus. In summary, denervation of hypothalamic serotonergic nerve terminals produces supersensitivity of some neuroendocrine responses to 8-OH-DPAT independent of changes in the density of hypothalamic 5-HT1A receptors.
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PMID:Alterations in 8-hydroxy-2-(dipropylamino)tetralin-induced neuroendocrine responses after 5,7-dihydroxytryptamine-induced denervation of serotonergic neurons. 965 67

In the adult rhesus monkey, yawning is an androgen-dependent sexually dimorphic behavior with males yawning more frequently than do females reflecting sex differences in circulating androgens. Studies in a variety of species indicate that yawning is mediated by various neurochemicals including dopamine, serotonin, and oxytocin. In rhesus monkeys, exogenous androgen reliably induces yawning in females to male-like levels. This study investigated whether flutamide, a nonsteroidal anti-androgen, reverses yawning induced by exogenous androgen administration in adult female rhesus monkeys. Six adult female rhesus monkeys were given chronic DHT alone and in combination with daily injections of flutamide and observed for yawning behavior. Treatment with DHT alone significantly increased yawning from 0.3 yawns per 30 min at the pretreatment baseline to 4.7 yawns per 30 min. Concurrent administration of flutamide significantly reduced the rate of yawning to 1.9 yawns per 30 min. These data indicate that flutamide is an effective tool for blocking the central effects of androgens in rhesus monkey females and that androgens regulate yawning similarly in both males and females.
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PMID:Androgen-induced yawning in rhesus monkey females is reversed with a nonsteroidal anti-androgen. 1605 25