Alpha-tocopherol prevents ethanol-induced elevation of [Ca2+]i in cultured canine cerebral vascular smooth muscle cells.

Exposure of cultured canine cerebral vascular smooth muscle cells to ethanol (10-400 mM) for 1-5 days results in concentration-dependent elevation in resting intracellular free calcium ([Ca2+]i) levels. Preincubation of these cultured vascular cells with alpha-tocopherol (20 microM), alone, did not produce any apparent changes from control resting levels of [Ca2+]i. However, after concomitant addition of alpha-tocopherol (20 microM) and ethanol (10-400 mM), the rises of [Ca2+]i induced by ethanol were attenuated markedly. These results suggest that alcohol-induced lipid peroxidation of cerebral vascular muscle cell membranes triggers membrane entry of extracellular Ca2+, which could play an important role in ethanol-induced cerebrovasospasm, brain ischemia and stroke. Moreover, these new results support the concept recently advanced to suggest that alpha-tocopherol-induced amelioration of membrane lipid alterations of cerebral vascular cells can prevent ethanol-induced excessive accumulation of [Ca2+]i.