Changes in the nature of calcium transport systems on the porcine sperm plasma membrane during epididymal maturation.
Comparative studies of 45Ca(2+)-transport across the plasma membrane were performed using porcine caput, corpus and cauda epididymal sperm. The Ca(2+)-uptake is dependent on the presence of the substrates for respiration and is sensitive to verapamil. The Ca(2+)-efflux is mediated by both Na(+)-dependent and -independent systems. In the immature sperm in caput epididymis, Na(+)-independent efflux is predominant, but it is gradually replaced by Na(+)-dependent efflux during the epididymal transit. The net activity of Ca2+ accumulation into sperm increases with the epididymal maturation.
Okamura
N
N
Institute of Basic Medical Sciences, University of Tsukuba, Ibaraki, Japan.
Fukuda
A
A
Tanba
M
M
Sugita
Y
Y
Nagai
T
T
D000818:Animals; D001692:Biological Transport; D002118:Calcium / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D004822:Epididymis / Q000254:growth & development / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D013094:Spermatozoa / Q000378:metabolism* / Q000648:ultrastructure; D013552:Swine
D002118:Calcium