Intimate association of H(+)-ATPase vesicles with mitochondria in the intercalated cell of the renal collecting duct.

It is known that the intercalated cell of the renal collecting duct contains, in addition to abundant mitochondria, characteristic spherical or flat vesicles whose cytoplasmic surfaces were decorated with H(+)-ATPase studs. The intimate association of H(+)-ATPase vesicles with mitochondria was often observed. Here, the limiting membrane of the vesicle and the outer mitochondrial membrane were directly connected to each other by H(+)-ATPase studs. Namely, two membranes were bridged by these studs. This feature was especially evident in the case of flat vesicles. These findings indicated the close interplay between these two cell organellae.