Hyperthermic stress affects the thermal modulation of glucocorticoid receptor affinity

Abstract

In vitro binding of a steroid hormone (triamcinolone acetonide) to hepatic glucocorticoid receptors was studied in liver cytosols prepared from untreated control rats and rats sacrificed after being exposed in vivo to whole body hyperthermia (41 or 428C). Positive temperature modulation of glucocorticoid–receptor affinity (decrease of affinity with increasing temperature) was well expressed in all preparations. In preparations from hyperthermic rats, alterations of a possible functional (adaptive) significance have been recorded: the amplitude of positive thermal modulation was reduced, and its lower-temperature limit shifted towards higher temperatures. # 2001 Elsevier Science Ltd. All rights reserved.