Effects of benidipine hydrochloride on cerebrovascular lesions in salt-loaded stroke-prone spontaneously hypertensive rats: Evaluation by magnetic resonance imaging

We determined possible protective effects of benidipine hydrochloride (beni dipine), a dihydropyridine calcium antagonist, on cerebrovascular lesions i n salt-loaded stroke-prone spontaneously hypertensive rats (SHRSP). The ani mals were orally treated with benidipine at 1, 3 and 10 mg/kg daily for 7 w eeks, and their neurological symptoms, body weight changes, systolic blood pressure and cerebrovascular lesions on magnetic resonance imaging (MRI) we re determined at various time points of treatment. Moreover, the brains of the rats that showed cerebrovascular lesions on MRI in the course of treatm ent or completed 7-week treatment were examined histopathologically. Contro l rats presented such symptoms as sedation, ataxia and aggressiveness, whil e their MRI analysis revealed high signals over wide areas from the occipit al to frontal cortex and from the corpus callosum to external capsule. Thes e high signal areas corresponded in location to edematous or softening lesi ons revealed by the histopathological observation. Treatment with benidipin e at 3 and 10 mg/kg ameliorated neurological symptoms, significantly suppre ssing cerebrovascular damages on MRI. Benidipine at 3 mg/kg significantly d ecreased blood pressure for the first four weeks but it did not thereafter. These findings demonstrate that benidipine can protect salt-loaded SHRSP f rom cerebrovascular injury as assessed by MRI.