Therapeutic effects of a calcium antagonist, lacidipine, on stroke-prone spontaneously hypertensive rats with cerebrovascular lesions

The aim of this study was to investigate the therapeutic effectiveness of l acidipine in stroke-prone spontaneously hypertensive rat (SHRSP) with cereb rovascular lesions in comparison with nicardipine. SHRSP were fed 1% saline as drinking water. After the onset of stroke, saline was replaced with wat er and each drug was administered orally once a day for 3 weeks. In the dru g-untreated group, recurrence of stroke was repeated, deterioration and ame lioration of neurological deficits (ND) were repeated, and histological exa mination and measurement of regional blood flow (rBF) using nonradioactive colored microspheres performed at the end of treatment revealed severe dama ges and significantly decreased rBF in brain and kidney, respectively. In k idney, not only lacidipine (1 mg/kg) but also nicardipine (30 mg/kg) decrea sed vascular lesions and ameliorated low-rBF significantly. Both drugs also inhibited the recurrence of stroke completely even at a low dose that did not ameliorate severe hypertension. Neuronal damages and ND in each lacidip ine-treated group were ameliorated significantly, whereas those in each nic ardipine-treated group were slightly improved. Lacidipine at 1 mg/kg alone ameliorated the cerebral low-rBF significantly even at 24 hr after administ ration. These results suggest that a long-lasting improvement of low-rBF af ter stroke may be useful in the treatment of SHRSP with cerebrovascular les ions.