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 oxytocic activity of the hot methanol extract (HME) of the leaves of Monechma ciliatum was compared with other uterine stimulants like ergometrine, oxytocin, 5-hydroxytryptamine (5-HT), acetylcholine (ACh) and prostaglandins (PGs) E2 and F2alpha (PGE2 and PGF2alpha) in the presence of some antagonists in an attempt to explain the mechanism of action of the extract. The effects of the reference drugs on uteri isolated from rats pretreated with HME for 2 weeks were also observed. Atropine blocked the effect of ACh and partially blocked those of HME while L-366-948 blocked only the effect of oxytocin. Indomethacin inhibited the effects of HME as well as all the other drugs, except the PGs and ACh. D-600 blocked the effect of all the drugs including HME. Methysergide antagonised only the effect of 5-HT and partially blocked ergometrine. Prolonged treatment altered the uterine musculature and the activity profile of the reference drugs. These results suggest that the HME may be acting by more than one mechanism to contract the uterus and explains the mechanism of the anti-implantation activity of the plant.
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PMID:Uterotonic properties of the methanol extract of Monechma ciliatum. 984 29

This study investigated the involvement of serotonergic mechanisms of the lateral parabrachial nucleus (LPBN) in the control of sodium (Na+) excretion, potassium (K+) excretion, and urinary volume in unanesthetized rats subjected to acute isotonic blood volume expansion (0.15 M NaCl, 2 ml/100 g of body wt over 1 min) or control rats. Plasma oxytocin (OT), vasopressin (VP), and atrial natriuretic peptide (ANP) levels were also determined in the same protocol. Male Wistar rats with stainless steel cannulas implanted bilaterally into the LPBN were used. In rats treated with vehicle in the LPBN, blood volume expansion increased urinary volume, Na+ and K+ excretion, and also plasma ANP and OT. Bilateral injections of serotonergic receptor antagonist methysergide (1 or 4 microg/200 etal) into the LPBN reduced the effects of blood volume expansion on increased Na+ and K+ excretion and urinary volume, while LPBN injections of serotonergic 5-HT(2a)/HT(2c) receptor agonist, 2.5-dimetoxi-4-iodoamphetamine hydrobromide (DOI; 1 or 5 microg/200 etal) enhanced the effects of blood volume expansion on Na+ and K+ excretion and urinary volume. Methysergide (4 microg) into the LPBN decreased the effects of blood volume expansion on plasma ANP and OT, while DOI (5 microg) increased them. The present results suggest the involvement of LPBN serotonergic mechanisms in the regulation of urinary sodium, potassium and water excretion, and hormonal responses to acute isotonic blood volume expansion.
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PMID:Serotonergic mechanisms of the lateral parabrachial nucleus in renal and hormonal responses to isotonic blood volume expansion. 1713 27

Previous studies from our laboratory have shown that methysergide, a serotonergic antagonist, injected into the lateral parabrachial nucleus (LPBN) combined with a pre-load of 2 M NaCl, given by gavage, induces 0.3 M NaCl intake. The mechanisms involved in this paradoxical behavior are still unknown. In the present work, we investigated the effect of serotonergic blockade into the LPBN on hindbrain and hypothalamic activity, gastric emptying and arterial blood pressure in cell-dehydrated rats. Methysergide plus 2 M NaCl infused intragastrically or intravenously promoted 0.3 M NaCl intake in two-bottle tests. In cell-dehydrated rats with no access to fluids, methysergide compared to vehicle increased Fos immunoreactivity in the medial nucleus of the solitary tract, area postrema and non-oxytocinergic cells of the ventral portion of the hypothalamic paraventricular nucleus (PVN). There was no alteration in the number of neurons double-labeled for Fos-ir and oxytocin in the PVN and supraoptic nuclei. There was also no alteration in plasma oxytocin and vasopressin, or arterial pressure. In rats cell-dehydrated by i.v. 2 M NaCl, methysergide also did not change the amount of an intragastric load of 0.3 M NaCl retained in the stomach or intestine. The results suggest that methysergide injected into the LPBN of cell-dehydrated rat does not alter primary inhibitory signals that control sodium intake. The inhibitory signals blocked by methysergide in the LPBN possibly originated from activation of brain osmoreceptors, second order visceral/hormonal signals or a combination of both.
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PMID:Sodium intake, brain c-Fos protein and gastric emptying in cell-dehydrated rats treated with methysergide into the lateral parabrachial nucleus. 2617 91