Brain catecholamines and the hypothalamo-hypophyseal-adrenocortical system in inherited arterial hypertension.

Rats with inherited stress-induced arterial hypertension (NISAG rats) and normotensive Wistar rats were used for studies of age-related changes in arterial pressure (BP), in the activity of the hypothalamo-hypophyseal-adrenocortical system (HHAS), and noradrenaline levels in brain structures involved in regulating these functions, with the aim of identifying possible relationships between them. It is suggested that the noradrenaline deficiency seen at the age of four weeks in the hypothalamus and medulla oblongata in NISAG rats is involved in the pathogenesis of hypertension and in disturbing the function of the HHAS. Transient increases in brain catecholamine synthesis in the fourth week of life lead to prolonged reductions in BP and complete recovery of HHAS responses to stress in adult animals. Correction of BP and HHAS function is accompanied by changes towards the normal in noradrenaline levels in the hypothalamus and medulla oblongata and in the numbers of alpha 1-adrenoceptors in the medulla oblongata.