title: Changes in calcium transport in mammalian sperm mitochondria and plasma membranes caused by 780 nm irradiation.
abstract: 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.
authors.affiliation: Department of Physics and Chemistry, Bar-Ilan University, Ramat Gan, Israel.
authors.forename: R
authors.initials: R
authors.lastname: Lubart
authors.forename: H
authors.initials: H
authors.lastname: Friedmann
authors.forename: M
authors.initials: M
authors.lastname: Sinyakov
authors.forename: N
authors.initials: N
authors.lastname: Cohen
authors.forename: H
authors.initials: H
authors.lastname: Breitbart
mesh_terms: 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
chemical_list: D002118:Calcium