An immunohistochemical and electrophysiological study on Isk protein in the stria vascularis of the guinea pig.

The reaction product against rat Isk protein antibody was demonstrated on the endolymphatic surface of the marginal cell of the guinea pig, using an immunohistochemical method. Clofilium, a potassium channel blocker which has been previously found to block rat kidney Isk channels, decreased the endocochlear potential (EP) when applied by perilymphatic perfusion and iontophoresis into endolymph. This finding of a decreased EP supports the presence of Isk protein on the endolymphatic surface of the marginal cell.