[Changes in endocochlear potential induced by potassium-channel blockers].

The effect of various potassium-channel blockers, 4-aminopyridine (4-AP), tetraethylammonium (TEA) and quinine, on the endocochlear potential (EP) was studied in perfused guinea pig inner ears. The fast K(+)-channel blocker, 4-AP, did not alter EP but changed its response model to intense noise exposure. While TEA and quinine significantly reduced the amplitude of negative component of EP (N-EP), comparing with a relatively smaller increase in general EP (G-EP). The results indicated the existence of different K(+)-channels with different physiological functions.