Immunocytochemical localization of sodium-calcium exchanger in canine nephron.

The sodium-calcium exchanger was localized in tissue sections of canine kidneys with two different polyclonal antisera raised against purified sodium-calcium exchanger protein derived from dog cardiac sarcolemma. The sodium-calcium exchanger was prominent in the basolateral plasmalemma of the majority of cells in all connecting tubules. In contrast, it was observed rarely and inconspicuously over the basolateral aspects of proximal tubular cells. The sodium-calcium exchanger was undetectable in all other portions of the nephron.