Differential effects of vasopressin (AVP) and oxytocin (OXT) on the baroreceptor reflex in conscious rats.
In conscious chronically instrumented, male Wistar rats the intracisternal (ic) administration of AVP (10ng) caused an increase in baroreflex sensitivity in response to both a rise and fall in blood pressure induced by intravenous phenylephrine (1/ug) and sodium nitroprusside (13/ug) respectively. Conversely a synthetic OXT analogue (Thr4 - Gly7) OXT (10ng) injected ic depressed baroreceptor reflex function. It appears that AVP and OXT are involved in the central connections of the baroreceptor reflex arc, where they may act as physiological antagonists.
D000818:Animals; D001127:Arginine Vasopressin / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects*; D004347:Drug Interactions; D008297:Male; D009599:Nitroprusside / Q000494:pharmacology; D010121:Oxytocin / Q000031:analogs & derivatives / Q000494:pharmacology*; D010656:Phenylephrine / Q000494:pharmacology; D011311:Pressoreceptors / Q000187:drug effects*; D051381:Rats; D011919:Rats, Inbred Strains; D012018:Reflex / Q000187:drug effects*
D001127:Arginine Vasopressin; D009599:Nitroprusside; D010656:Phenylephrine; D010121:Oxytocin; C045427:oxytocin, Thr(4)-Gly(7)-