Endocrinology Vol. 140, No. 2 1013-1017
Copyright © 1999 by The Endocrine Society
CRF Type I Receptor-Deficient Mice Exhibit a Pronounced Pituitary-Adrenal Response to Local Inflammation
Andrew V. Turnbull,
George W. Smith,
Soon Lee,
Wylie W. Vale,
Kuo-Fen Lee and
Catherine Rivier
Clayton Foundation Laboratories for Peptide Biology, The Salk
Institute, La Jolla, California 93037; NWIRC, University of Manchester,
Stopford Building, M13 9PT, United Kingdom, Department of Animal
Science, Michigan State University, East Lansing, Michigan 48824 and
Psychiatry (D.D.R., C.W.W.) University of Washington, Seattle,
Washington 98195; and Department of Physiology (S.M.Y.), Loma Linda
University, Loma Linda, California, 92350
Address all correspondence and requests for reprints to: Catherine L. Rivier, Ph.D., Salk Institute, Peptide Biology Lab, 10010 North Lorrey Pines Road, La Jolla, California 92037-1002.
 |
Abstract
|
|---|
Recent studies indicate that the regulation of adrenocorticotropin
(ACTH) secretion by corticotropin-release factor (CRF) is mediated
predominantly by the type I CRF receptor (CRF-R1). Indeed,
CRF-R1-deficient (CRF-R1 -/-) mice show marked impairment of the
pituitary-adrenal axis. However, the plasma ACTH concentrations of
unstressed CRF-R1 -/- mice are similar to those in wild-type mice.
We show here that arginine vasopressin (AVP) is a major ACTH
secretagogue in CRF-R1 -/- mice in resting conditions, since
administration of anti-AVP serum, but not anti-CRF serum, markedly
reduced (by 60%) resting plasma ACTH concentrations in these mutants.
We also investigated the pituitary-adrenal response to
turpentine-induced local inflammation in CRF-R1 -/- mice.
Administration of turpentine into the hind-limb of CRF-R1 -/- mice
produced a slightly (1525%) smaller swelling of the limb, but a 10
fold greater rse in plasma IL-6 levels, compared to CRF-R1 +/+
controls. Turpentine-induced local inflammation produced pronounced
elevations in the plasma concentrations of both ACTH and corticosterone
in both CRF-R1 -/- and wild-type mice, but ACTH secretion could be
inhibited by anti-CRF and anti-AVP sera only in wild-type mice. These
data indicate that resting ACTH secretion in CRF-R1 -/- mice is in
part attributable to AVP-dependent mechanisms. Furthermore, while in
normal mice the pituitary-adrenal response to local inflammation is
mediated largely via CRF-dependent mechanisms, mice deficient in CRF-R1
are still able to mount a pituitary-adrenal response via mechanisms
that do not depend critically on either CRF or AVP action.
Received September 30, 1998.