Acute Effect of Traumatic Stress on Cortisol Metabolism in Man

Abstract

Plasma disappearance rates of 4-¹⁴C-cortisol or unlabeled cortisol, or both, were measured in relatively healthy patients before and again during laparotomy. The biologic halftime of labeled cortisol during surgery was unchanged or decreased slightly from the control value. When pharmacologic amounts of unlabeled cortisol were injected along with the labeled steroid, their half-times under nonstressful conditions were approximately equal. During surgery the half-time of unlabeled cortisol was significantly prolonged although halftime of labeled cortisol at the same time remained unchanged. Plasma disappearance of unlabeled cortisol was not delayed during laparotomy in patients whose plasma 17-hydroxycorticoid response had been suppressed by treatment with dexamethasone for several days before surgery. In 2 other patients who were not suppressed but had adrenalectomy at surgery, cortisol disappearance rates were also similar to preoperative values. Under nonstressful conditions the half-time of unlabeled cortisol was prolonged in normal subjects while they were receiving constant infusions of cortisol, but neither cortisol nor ACTH infusions significantly altered the halftime of labeled cortisol. These findings indicate that, in relatively healthy patients, traumatic stress of itself does not result in impaired plasma cortisol removal. An apparent delay in removal of exogenous cortisol during surgery may be partly explained on the basis of increased adrenal secretion and elevated plasma levels of endogenous cortisol.