Acidification of the male reproductive tract by a proton pumping (H+)-ATPase.
An acidic luminal pH (ref. 1-3) is involved in sperm maturation, and in maintaining sperm in an immotile state in the epididymis and vas deferens (2,4-6). Neutralization by prostatic fluid is one of a complex series of events that triggers sperm motility (2,7,8). Failure of the acidification mechanism might, therefore, result in poor sperm maturation, premature motility and infertility. We have shown that a vacuolar (H+)-ATPase is expressed at high levels on the luminal plasma membrane of specialized cells in the epididymis (9), which closely resemble acid-secreting kidney intercalated cells (10,11). We now show that similar cells are also present in the vas deferens, and that a bafilomycin-sensitive proton flux can be detected using a noninvasive proton-selective vibrating probe. Up to 80% of the net proton secretion in the vas deferens is inhibited by bafilomycin, consistent with a major role of a vacuolar-type (H+)-ATPase in this process. This acidification mechanism is a potential target for novel strategies aimed at modulating the acidification capacity of parts of the male reproductive tract and, therefore, in regulating male fertility.
Breton
S
S
Renal Unit, Massachusetts General Hospital, Boston, Massachusetts 02129, USA.
Smith
P J
PJ
Lui
B
B
Brown
D
D
D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D018942:Macrolides; D008297:Male; D017494:Proton Pumps / Q000187:drug effects / Q000502:physiology*; D006180:Proton-Translocating ATPases / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013079:Sperm Maturation; D014649:Vas Deferens / Q000502:physiology*
D000900:Anti-Bacterial Agents; D018942:Macrolides; D017494:Proton Pumps; C057620:bafilomycin A; D006180:Proton-Translocating ATPases