Intracisternal sauvagine is more potent than corticotropin-releasing factor to decrease gastric vagal efferent activity in rats.
Consecutive intracisternal (ic) injections of corticotropin-releasing factor (CRF) (21, 63, and 126 pmol, ic) or sauvagine (2.1, 6.3, and 21 pmol, ic) decreased gastric vagal efferent multiunit discharge (GVED) to 82%, 75% and 69% and 71%, 40% and 21%, respectively, from preinjection basal levels (taken as 100%). The inhibitory action was dose related (magnitude and duration of the response, 7-45 min). The CRF antagonist, [D-Phe12,Nle21,38,Calpha-MeLeu37]-rCRF12-4 1 (6.25 nmol, ic) increased GVED by 43.5+/-4.3% and blocked the decrease in GVED induced by CRF (21 pmol, ic) for >90 min with a complete recovery after 3 h. Vehicles (injected intracisternally) had no effect. These data indicate that: 1) CRF injected intracisternally decreases GVED through the activation of CRF receptors and sauvagine is more potent than CRF to inhibit GVED; and 2) endogenous CRF exerts an inhibitory tone on basal GVED in urethane-anesthetized rats undergoing surgery.