Cerebral vascular changes in experimentally induced hypertensive rats

ABSTRACT

To study the pathogenesis of cerebral vascular changes in hypertension, especially those predisposing to hemorrhage, we set out to produce a hypertensive rat model by the Goldblatt [2 kidney-1 clip] method. Materials and Fifty rats were rendere d hypertensive by the Goldblatt method in which the left renal artery was ligated surgically. The animals, together with 18 control rats, were divided into three groups as follows a] on normal diet and water, b] on normal diet and 1% salt water and c] on normal diet and drinking water containing 0.12% of the lathyrogen beta a m i n o p roprionitrile [BAPN]. Slices of brain were examined both macroscopically and microscopically for morphological changes in the cerebral vessels. Mean arterial blood pressures achieved were only moderate [170 mmHg] and corresponding cerebral vascular changes were mild to moderate. None of the s e v e re lesions [hemorrhages, fibrinoid necrosis, microaneurysms, etc.] known to be associated with severe or long-standing hypertension were demonstrated in this study. A few vessels in six animals showed fibrin deposition in the wall, although these could not be directly related to the severity of hypertension or duration of survival of the animal. The six, as well as three additional animals, also showed immunoglobulin G [IgG] deposition in the vessel walls and perivascular tissues within the brain. We have successfully established a rat model for the study of hypertension-related cerebral vascular changes. The deposits of fibrin and IgG in the vessel wall and surrounding tissues re p resent early changes, which appear to occur even in the absence of severe hypertensive vascular disease. Further studies are required to determine the relevance of these changes to other known morphological changes of the cerebral vasculature in hypertension