INTERACTIONS OF OXYTOCIN AND VASOPRESSIN WITH CRF ON THE RAT COLON

Corticotropin-releasing factor (CRF), a primary mediator of stress res ponses, produces changes in the gastrointestinal tract identical to th ose induced by stress. CRF is tenfold more potent in females than in m ales, but gonadectomy reverses this difference. We postulated that pos itive modulators of CRF, such as oxytocin (OT) and vasopressin (AVP), may act in females to potentiate effects of CRF and thus could account for the gender-related differences in colonic sensitivity to CRF and stress. Given with CRF, neither OT, peripheral AVP, nor central AVP in creased colonic transit any more than CRF alone, suggesting that OT an d AVP do not potentiate CRF's actions in the colon. These data indicat e that endogenous OT and AVP do not directly affect colonic transit, a nd that OT and AVP do not account for the gender-related differences i n the effects of stress and CRF on colonic transit.