AJP - Regulatory, Integrative and Comparative Physiology, Vol 266, Issue 1 180-R187, Copyright © 1994 by American Physiological Society

ARTICLES

Corticotropin responses to hypoglycemia and hypotension during ovine pregnancy

M. Keller-Wood
Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville 32610-0487.

The adrenocorticotropic hormone (ACTH) responses to hypoglycemia and to hypotension were compared in pregnant and nonpregnant ewes. In the first study pregnant and nonpregnant ewes were each subjected to hypoglycemia induced by injection of 0.05, 0.10, or 0.25 U regular insulin/kg body wt or to saline infused as a control. In the second study pregnant and nonpregnant ewes were subjected to hypotension induced by the infusion of 2.5, 5.0, or 10.0 micrograms nitroprusside.kg-1.min-1 or to dextrose infused as a control. ACTH responses to hypoglycemia were significantly increased in the pregnant ewes, and the relation between plasma glucose and plasma ACTH was shifted to the right, indicating greater ACTH responses for a given level of hypoglycemia in the pregnant state. The mean ACTH response to infusion of nitroprusside was reduced during pregnancy, despite significantly lower mean arterial blood pressure in the pregnant ewes. When the relation between mean arterial pressure and ACTH was compared in the two groups of ewes, the relation was significantly shifted to the left in the pregnant ewes, indicating lower ACTH responses to a given level of pressure during pregnancy. The results suggest that pregnancy does not uniformly alter ACTH responses to stimuli, suggesting multiple, stimulus-specific effects of pregnancy on the hypothalamo-pituitary-adrenal axis.

This article has been cited by other articles:

				S. F. Young and J. C. Rose Attenuation of Corticotropin-Releasing Hormone and Arginine Vasopressin Responsiveness During Late-Gestation Pregnancy in Sheep Biol Reprod, June 1, 2002; 66(6): 1805 - 1812. [Abstract] [Full Text] [PDF]

				M. Keller-Wood ACTH responses to CRF and AVP in pregnant and nonpregnant ewes Am J Physiol Regulatory Integrative Comp Physiol, June 1, 1998; 274(6): R1762 - R1768. [Abstract] [Full Text] [PDF]