AJP - Cell Physiology, Vol 263, Issue 4 C913-C916, Copyright © 1992 by American Physiological Society
A plasma membrane proton ATPase in specialized cells of rat epididymis
D. Brown, B. Lui, S. Gluck and I. Sabolic
Renal Unit, Massachusetts General Hospital, Boston.
Acidification of the luminal fluid in the epididymis is believed to play an
important role in sperm maturation. Previous studies have shown that
specialized cells in the epithelium lining the epididymis contain high
levels of carbonic anhydrase and that these cells have rod-shaped
intramembraneous particles when examined by freeze fracture. Both of these
features are characteristic of proton-transporting intercalated cells in
the kidney collecting duct. We now show that apical cells in the head of
the epididymis and clear cells in the body and tail of the epididymis
express high levels of a vacuolar proton-pumping adenosinetriphosphatase on
their apical plasma membranes and on intracellular vesicles. By analogy
with kidney intercalated cells, these cell types may be specialized for
acid secretion in the epididymis.
