pp60(c-src) increases voltage-operated calcium channel currents in vascular smooth muscle cells

Intracellular application of pp60(c-src), a nonreceptor tyrosine kinase present in large amounts in smooth muscle cells increased voltage-operated calcium channel currents in rabbit ear artery cells. Intracellular peptide-A, an inhibitor of pp60(c-src), reduced calcium channel currents and abolished the action of pp60(c-src). Selective tyrosine kinase inhibitors, tyrphostin-23 and genistein also abolished the effect of pp60(s-src), but inhibition of protein kinase C did not prevent the action of pp60(c-src). These results suggest that endogenous pp60(c-src) modulates voltage-operated calcium channels by a mechanism dependent on tyrosine phosphorylation but not involving activation of protein kinase C. (C) 1995 Academic Press, Inc.