The pathogenesis of small arterial lesions in nephrectomized rats by the administration of renin.

Intraperitoneal injection of purified hog renal renin produced a marked and sustained elevation of arterial pressure and lesions of the "fibrinoid necrosis" type in the small arteries and arterioles of the pancreas, heart and mesentery, but not of the brain, in bilaterally nephrectomized rats. Both the elevation of arterial pressure and the production of arterial lesions were completely prevented by pretreatment with oral SQ14225. Plasma renin clearance in bilaterally nephrectomized rats was markedly slower than that in sham-nephrectomized rats. Pre-treatment with oral SQ14225 did not affect renin clearance. It is suggested that sustained high blood pressure due to the sustained high plasma renin concentration in bilaterally nephrectomized rat was responsible for the production by renin of lesions of the fibrinoid necrosis type in the arteries.