Serum 11-deoxycorticosterone levels in adrenal-regeneration hypertension under conditions of quiescence and stress

Abstract

A time course study to measure adrenal cortical function was undertaken for the period prior to the development of hypertension until the onset of hypertension in the adrenal-regeneration hypertension (ARH) model. Quiescent rat kills were used so that all adrenal cortical parameters investigated would reflect basal or resting levels for controls. Thus a more accurate determination of the differences between control and experimental animals could be made. A radioimmunoassay procedure for deoxycorticosterone was developed to measure this steroid in individual rat serum samples. Elevated serum deoxycorticosterone levels were observed in rats with regenerating adrenals when they were killed under quiescent conditions. This agreed with our recently reported in vitro finding of restoration of cholesterol side chain cleavage activity while 11β-hydroxylase activity remained impaired 25 days after adrenal enucleation. When rats were killed after ether stress, deoxycorti-costerone levels were elevated in both control rats and in rats with regenerating adrenals but the difference was not significant. In contrast, after ether stress serum corticosterone levels were lower in rats with regenerating adrenals than in controls. These studies, in conjunction with our previous in vitro findings, point to the importance of deoxycorticosterone in the pathogenesis of adrenal regeneration hypertension and help to explain the anomalous corticosteroid secretion rate data found in this experimental hypertension model.