AJP - Endocrinology and Metabolism, Vol 240, Issue 2 136-E145, Copyright © 1981 by American Physiological Society
Nonsteroidal adrenal feedback demarcates two types of pathways to CRF-ACTH release
C. W. Wilkinson, W. C. Engeland, J. Shinsako and M. F. Dallman
We have tested the relationship between corticosterone (B) and the number
of adrenal glands on stimulated corticotropin (ACTH) levels in rats. Rats
were supplied throughout the experiment with various doses of B in the
drinking fluid beginning 15-20 h before adrenal surgery. Bilateral,
unilateral, or sham adrenalectomy was followed on the 3rd day by the
stimulus of ether vapor or ether and laparotomy with intestinal traction.
Plasma ACTH levels 3 min after the stimuli were decreased by both the dose
of B and adrenal number; the adrenal number of adrenals, although
prestimulus ACTh and B levels were similar across groups. The decrease in
ACTH after ether resulted from an interaction between the dose of B and the
however there was no interaction between the inhibitors after laparotomy
with intestinal traction. These results show that 1) in addition to B, some
aspect of adrenal gland number or mass inhibits the ACTH response to
stimuli; and 2) the adrenal number input serves as a marker to distinguish
between stimuli to ACTH secretion that are inhibited by B at sites proximal
and those that are inhibited by B at sites distal to this input.
