Povstyan O. Membrane mechanisms of apamin action on smooth muscle cell ionic currents.

The dissertation is devoted to pharmacological and biophysical investigations of components of transmembrane ionic currents in SMCs isolated from guinea pig taenia coli and to clarification the membrane mechanisms of apamin action on them. It was found two K(Ca) currents, which differs by them channels conductance, sensitivity to [Ca2+]i, membrane potential, relation to blockers (apamin, charybdotoxin, TEA), and kinetic characteristics. For the first time it has been shown that action of apamin on ionic currents of guinea pig taenia coli SMCs include two mechanisms: blocking of small conductance K(Ca) channels - on one hand and activation of cationic conductance - on the other hand.