Article: PDF OnlyNickerson Peter A.Journal of Cardiovascular Pharmacology: 1987 - p S31-S37 Free Abstract Summary Protection from vascular lesions by a calcium antagonist was studied in hypertension induced by deoxycorticosterone (DOC). Nitrendipine was administered at a low dose (1 mg/kg, 2 × day) to rats bearing pellets of DOC. DOC induced a significant increase in the systolic blood pressure to hypertensive levels. The systolic blood pressure in rats receiving a low dose of nitrendipine combined with DOC did not differ significantly from that of DOC-treated rats at 3 weeks. The incidence and severity of vascular lesions in kidney and heart induced by DOC was ameliorated by nitrendipine. Thus we were able to dissociate, in part, the effect of elevated blood pressure from induction of vascular lesions. Study of colloidal carbon or horseradish peroxidase as tracers of vascular permeability showed that these tracers were retained within the vasculature of animals treated with nitrendipine plus DOC, controls, or in nitrendi-pine-injected rats. In contrast, the tracers were observed outside of vessels in areas of increased lesions pointing to increased vascular permeability in induction of the lesions. Protection may be mediated by an effect of the calcium antagonist on the endothelium of hypertensive animals. Concomitantly, a direct effect on the vascular smooth muscle cannot be excluded. © Lippincott-Raven Publishers.