ACUTE COCAINE RESULTS IN RAPID RISES IN INTRACELLULAR FREE CALCIUM-CONCENTRATION IN CANINE CEREBRAL VASCULAR SMOOTH-MUSCLE CELLS - POSSIBLERELATION TO ETIOLOGY OF STROKE

Effects of cocaine on intracellular free calcium concentration ([Ca2+] (i)) in cultured canine cerebral vascular smooth muscle cells were stu died using digital imaging microscopy acid the calcium molecular fluor escent indicator, fura-2. Acute treatment of cerebral vascular smooth muscle cells with cocaine HCl, from a low concentration of 10(-9) M up to 10(-5) M, induced significant increases of [Ca2+](i). irrespective of the changes in [Ca2+](i), the subcellular distribution of [Ca2+](i ) appeared heterogeneous in both normal and cocaine-treated cells. The se results suggest that cocaine induces cerebral vasospasm by a rapid elevation of [Ca2+](i) in vascular smooth muscle cells; these ionic ev ents could play a crucial role in the pathogenesis of cocaine-induced cerebral ischemia and stroke.