Microanatomical changes of intracerebral arteries in spontaneously hypertensive rats: a model of cerebrovascular disease of the elderly

Changes occurring in intracerebral arteries of 24-week-old spontaneously hy pertensive rats (SHR) compared with age-matched normotensive Wistar-Kyoto ( WKY) rats were assessed using microanatomical techniques associated with im age analysis. Morphometric parameters investigated included arterial diamet er, lumen area, wall area, and wall-to-lumen ratio. Intracerebral arteries (lumen diameter > 46 mum) and arterioles (lumen diameter 46-10 mum) of fron tal cortex, striatum, and hippocampus were examined. In frontal cortex of S HR arterial wall hypertrophy and luminal narrowing were observed. In striat um, an increase of wall area not accompanied by luminal narrowing predomina tes resulting in arterial hypertrophy without vasoconstriction. In hippocam pal arteries of SHR, luminal narrowing, without changes of wall area was fo und indicating the occurrence of remodeling. In brain areas investigated, h ypertensive changes affected primarily arterioles. The demonstration of a s ensitivity of intracerebral arteries to hypertension suggests that changes of these vessels may represent a cause of brain structural alterations occu rring in hypertension. The specificity of alterations occurring in intracer ebral arteries of brain areas investigated may account for the different lo calization of cerebral lesions in cerebrovascular disease. The possibility that microanatomical changes developed in intracerebral arteries of SHR may represent a model of cerebrovascular disease of the elderly is discussed. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.