Vasopressin responses to corticotropin-releasing factor and hypertonicity after truncal vagotomy in dogs. Raff, Hershel, Paula E. Papanek, and Verne E. Cowles. Departments of Physiology, Medicine and Surgery, Medical College of Wisconsin; Surgical Research Program, Zablocki Veterans Administration Medical Center; Physical Therapy Program, Marquette University; and Endocrine Research Laboratory, St. Luke's Medical Center, Milwaukee, WI 53215
APStracts 2:0209R, 1995.
Infusion of corticotropin-releasing factor (CRF) augments the plasma vasopressin response to infusion of hypertonic saline in conscious dogs. Furthermore, afferent vagal nerve input from the abdomen is involved in the control of vasopressin release and may be altered by CRF. The purpose of the present study was to characterize the effect of CRF on the vasopressin response to hypertonic saline and to determine if it is mediated by afferent input carried from the abdominal vagus. Conscious, male dogs (n=5) underwent infusion of isotonic saline (vehicle), CRF (10 or 20 ng/kg/min), hypertonic saline (0.2 mmol/kg/min), or the combination of CRF and hypertonic saline. Hypertonic saline increased plasma sodium from 147+/-1 to 153+/-1 meq/L and plasma vasopressin from 2.5+/-0.1 to 5.8+/-0.4 pg/ml. CRF infusion alone had no effect on plasma vasopressin. The addition of 10 or 20 ng/kg/min CRF augmented the vasopressin response to hypertonic saline to 7.7+/-1.7 and 6.9+/-0.3 pg/ml, respectively. Truncal vagotomy did not attenuate the vasopressin response to hypertonic saline without or with CRF infusion. We conclude that CRF augments the vasopressin response to hypertonic saline and that this effect is not mediated via afferents from the abdominal vagus.

Received 3 April 1995; accepted in final form 18 July 1995.
APS Manuscript Number R223-5.
Article publication pending Am. J. Physiol. (Regulatory Integrative
Comp. Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 30 July 1995.