Hypothalamo-pituitary-adrenocortical function in the ontogenesis in rats with hereditary stress-induced arterial hypertension

Abstract

Functional activity of the hypothalamo-pituitary-adrenocortical system (HPAS) was evaluated over time in rats with hereditary stress-induced arterial hypertension (HSIAH) and normotensive Wistar rats. Peripheral blood plasma corticosterone was measured in rats aged 2, 3, 4, 6, 8, 10, 12, and 18 weeks at rest and after 1-h immobilization in perforated cylinders by competitive protein binding. Basal corticosterone level and HPAS reaction to stress were lower in hypertensive rats than in Wistar rats of the same age. The only exclusion was the age of 4 weeks, when hypertension starts to form in HSIAH rats and their HPAS is more sensitive to emotional stress than that of Wistar rate, this sensitivity being associated with increased adrenal reaction to ACTH. Decreased HPAS reaction to emotional stress in adult HSIAH rats was not associated with disorders in adrenal sensitivity to ACTH.