Ultracytochemical Study of Ouabain-sensitive K+-dependent p-nitro-phenylphosphatase Activity in Stria Vascularis of Reserpinized Guinea Pigs

In order to clarify the effect of reserpine on the Na(+)-K+ active transport in the stria vascularis we investigated the localization of ouabain-sensitive K(+)-dependent p-nitro-phenylphosphatase (K-NPPase) activity in the stria vascularis of reserpinized guinea pigs using the cerium-based method. The K-NPPase activity in marginal cells differed from cell to cell, and was almost completely absent in some cells. These results are consistent with the previous results and suggest that Na(+)-K+ active transport in the stria vascularis may be inhibited by reserpine administration.