INVOLVEMENT OF GLIBENCLAMIDE-SENSITIVE POTASSIUM CHANNELS IN VASORELAXATION BY COCHLEAR NERVE-STIMULATION

Rabbit aortic rings relaxed with an increase in cyclic guanosine monop hosphate and cyclic adenosine monophosphate content in response to exp osure to organ fluid of isolated cochleas of the guinea pig following field stimulation (50 Hz, 80 V, 0.2 ms). Relaxations were blocked by 3 0 mu M N-G-nitro-L-arginine methyl ester added to the vessel rings Thi s inhibitory effect was reversed by 3 mM L-arginine. Removal of the va scular endothelium also blocked the relaxation response, Glibenclamide attenuated vasorelaxation in a concentration-dependent manner, We con clude that cochlear nerve stimulation induces an endothelium-dependent vasorelaxation involving activation of adenosine triphosphate-sensiti ve potassium channels.