Localization of K+-stimulated p-NPPase in the lachrymal 'salt' gland of Malaclemys, using cytochemical and autoradiographical techniques.

Using two independent techniques, histochemistry and autoradiography, an enzyme (E.C. 3.6.1.3.) has been localized on basolateral cell membranes of salt secreting cells in the lachrymal gland of Malaclemys. This enzyme is ouabain sensitive. In addition an L-tetramisole sensitive alkaline phosphatase is found in the same sites, and an ethacrynic acid sensitive K+-stimulated p-NPPase is found on the apical membrane. The significance of these results with regard to the location of the pump responsible for net transepithelial sodium transport is discussed.