Spontaneous stroke in renovascular hypertensive rats.

Abstract

To the Editor: Zeng and colleagues1 recently published a potentially important study on the spontaneous stroke in 2-kidney, 2-clip renovascular hypertensive rats. Blood pressure rose to an average of 225 mm Hg 6 weeks postoperatively. Animals displaying neurological symptoms were killed on the third day, and those surviving without neurological symptoms were killed at postoperative week 40. Stroke occurred in 34, including 7 hematomas in 55 animals (61.8%). Microscopic examination revealed fibrinoid necrosis, hyaline degeneration, and hyperplasia of the walls of arterioles and small arteries with or without cell proliferation in the brain. These vascular lesions were not observed in the hypertensive animals without gross brain lesions. I read this paper with great interest, because we published a paper on the cerebral hemorrhage in renovascular hypertensive rabbits over 30 years ago.2 Despite the species difference, there are many similarities between the 2 studies. I would like to compare the recent study by Zeng and colleagues with our old one and offer some comments. In our old study,2 we made rabbits hypertensive by the 2-kidney, 2-clip or 1-kidney, 1-clip procedure. The 2-kidney, 2-clip group was divided into one with moderate …