The biochemical characteristics of stress-sensitive hypertensive rats.

The biological characteristics of a line of stress-sensitive hypertensive (SSH) rats genetically selected from Wistar rats are described, in particular the dynamics of arterial blood pressure and the biochemical properties of the Na(+)-K+ ATPase present in the outer renal medulla. Changes in the specific activity of this enzyme are discussed in terms of the lipid composition of the membrane bilayer and the amount of endogenous ouabain-like compounds present in the blood of the animals under study. Rats of both strains, Wistar and SSH, were studied under conditions of rest and stress (8 day regime of daily 30 min immobilization). The production in vivo of adrenal mineralocorticoids and glucocorticoids is estimated and several biochemical features of the pathogenesis of essential hypertension are discussed.