Changes in calcium transport in mammalian sperm mitochondria and plasma membranes caused by 780 nm irradiation.
OBJECTIVE
Regulation of intracellular Ca2+ concentrations are very important in control of sperm motility and acrosome reaction. It was shown previously that low-power lasers in the visible and near-infrared range alter Ca2+ uptake by sperm cells. In the present work the effect of a 780 nm diode laser on Ca2+ uptake by sperm mitochondria and isolated plasma membrane vesicles is investigated.


METHODS
Digitonin-treated spermatozoa and plasma membrane vesicles were irradiated with a 780-nm diode laser at various powers and energy doses, and Ca2+ uptake was measured by the filtration method.


RESULTS
It was found that 780-nm irradiation inhibits Ca2+ uptake by the mitochondria but stimulates Ca2+ binding by sperm plasma membrane vesicles. The effect of light on Ca2+ uptake by plasma membrane vesicles in the absence of ATP was much larger than that measured in the presence of ATP. Addition of Ca2+ ionophore decreased the Ca2+ uptake by the irradiated membranes in the presence of ATP but enhanced it significantly in the absence of ATP.


CONCLUSIONS
780 nm light inhibits Ca2+ uptake by sperm mitochondria and enhances Ca2+ binding to sperm plasma membranes.
Lubart
R
R
Department of Physics and Chemistry, Bar-Ilan University, Ramat Gan, Israel.
Friedmann
H
H
Sinyakov
M
M
Cohen
N
N
Breitbart
H
H
D000818:Animals; D001692:Biological Transport / Q000528:radiation effects; D002118:Calcium / Q000378:metabolism*; D002417:Cattle; D002462:Cell Membrane / Q000378:metabolism*; D002478:Cells, Cultured; D007834:Lasers; D008297:Male; D008928:Mitochondria / Q000378:metabolism*; D011829:Radiation Dosage; D013094:Spermatozoa / Q000378:metabolism* / Q000648:ultrastructure
D002118:Calcium