Adrenal hormones and the anorectic response and adaptation of rats to amino acid imbalance.
The role of adrenal function in the anorectic response and adaptation of rats to a diet with an isoleucine (Ile) imbalance was investigated. In the first of four experiments, rats were fed a mildly Ile-imbalanced diet after treatment with metyrapone, and inhibitor of glucocorticoid synthesis. In two separate experiments, rats were presented with either a mildly or severely Ile-imbalanced diet (4.93 and 9.86% imbalanced amino acid mixture, respectively) after bilateral adrenalectomy. Finally, the effects of ICS 205-930, a serotonin-3 receptor antagonist, on the intake of mildly Ile-imbalanced diet were tested in adrenalectomized animals. In each experiment a 2 X 2 factorial design was used. Neither metyrapone nor adrenalectomy altered the initial depression in the intake of an imbalanced diet. The adaptation phase in the response of adrenalectomized rats fed a mildly Ile-imbalanced diet was not different from that of controls, but adrenalectomized rats fed severely Ile-imbalanced diets were unable to adapt. Adrenalectomy did not alter the anti-anoretic activity of ICS 205-930 in this model. These results suggest that adrenal hormones are not necessary for the initial anoretic response or adaptation of rats to an Ile-imbalanced diet, nor are they implicated in the anti-anorectic effect of serotonin-3 blockade.
Hammer
V A
VA
Department of Physiological Sciences, School of Veterinary Medicine, University of California, Davis 95616.
Gietzen
D W
DW
Sworts
V D
VD
Beverly
J L
JL
Rogers
Q R
QR
D000222:Adaptation, Physiological; D000305:Adrenal Cortex Hormones / Q000502:physiology*; D000315:Adrenalectomy; D000596:Amino Acids / Q000008:administration & dosage*; D000818:Animals; D000855:Anorexia / Q000503:physiopathology*; D004032:Diet; D004435:Eating / Q000187:drug effects; D007211:Indoles / Q000494:pharmacology; D007532:Isoleucine / Q000008:administration & dosage*; D008297:Male; D008797:Metyrapone / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D012702:Serotonin Antagonists / Q000494:pharmacology; D000077526:Tropisetron
D000305:Adrenal Cortex Hormones; D000596:Amino Acids; D007211:Indoles; D012702:Serotonin Antagonists; D007532:Isoleucine; D000077526:Tropisetron; D008797:Metyrapone