ELECTRON MICROSCOPIC DEMONSTRATION OF ADENOSINE TRIPHOSPHATE PHOSPHOHYDROLASE ACTIVITY IN HERRING GULL SALT GLANDS

Sites of adenosine triphosphate phosphohydrolase activity were demonstrated in herring gull salt glands with a cytochemical lead technique, utilizing fixed and unfixed tissue sections and a modified Wachstein and Meisel incubation media. The principal modifications in the procedure as recommended by Wachstein and Meisel included shortening the time of fixation and decreasing lead concentration while increasing the substrate concentration of the incubation media. Several different types of controls were run. In fixed tissues tested with an unmodified media, reaction product was deposited in capillary endothelial cells, tubular lumens and intercellular channels of central canal cells and nucleoli. Evidence is presented that none of these reactive sites contain a true adenosine triphosphate phosphohydrolase. With a modified procedure adenosine triphosphate-specific reaction product was deposited within the matrix of mitochondria, along the inner surface of the plasma membrane that lines the base of the principal salt-secreting cells and on the centriolar tubules. The possible validity of these reaction product localizations is discussed.