Calcium antagonists decrease capillary wall damage in aging hypertensive rat brain

Chronic hypertension during aging is a serious threat to the cerebral vascu lature. The larger brain arteries can react to hypertension with an abnorma l wall thickening, a loss of elasticity and a narrowed lumen. However, litt le is known about the hypertension-induced alterations of cerebral capillar ies. The present study describes ultrastructural alterations of the cerebro cortical capillary wall, such as thickening and collagen accumulation in th e basement membrane of aging spontaneously hypertensive stroke-prone rats. The ratio of cortical capillaries with such vascular pathology occurred sig nificantly more frequently in hypertensive animals. Nimodipine and nifedipi ne are potential drugs to decrease blood pressure in hypertension but their beneficial effects in experimental studies reach beyond the control of blo od pressure. Nimodipine and nifedipine can alleviate ischemia-related symptoms and impro ve cognition. These drugs differ in that nifedipine, but not nimodipine red uces blood pressure at the here-used concentration while both drugs can pen etrate the blood-brain barrier. Here we show that chronic treatment of agin g hypertensive stroke-prone rats with nimodipine or nifedipine could preser ve microvascular integrity in the cerebral cortex. (C) 2001 Elsevier Scienc e Inc. All rights reserved.