Studies on the mechanism of capacitation: albumin-mediated changes in plasma membrane lipids during in vitro incubation of rat sperm cells.
Plasma membrane isolated from rat sperm cells after incubation in vitro had a significantly lower cholesterol/phospholipid mole ratio when the medium contained serum albumin. Transfer of albumin-bound phospholipids to the membrane can largely account for this effect. The result is broadly consistent with a previously proposed model for albumin-induced destabilization of sperm membrane (capacitation) and its reversal by seminal plasma membrane vesicles. Albumin also decreased sialic acid and, more specifically, ganglioside levels, presumably by promoting release of sperm neuraminidase. Cholesteryl ester comprised up to 0.5 mol/mol of cholesterol in these plasma membrane preparations.
D000251:Adenosine Triphosphatases / Q000378:metabolism; D000818:Animals; D002458:Cell Fractionation / Q000379:methods; D002462:Cell Membrane / Q000502:physiology*; D002499:Centrifugation, Density Gradient; D002784:Cholesterol / Q000378:metabolism; D002788:Cholesterol Esters / Q000378:metabolism; D008297:Male; D008563:Membrane Lipids / Q000502:physiology*; D010743:Phospholipids / Q000378:metabolism; D051381:Rats; D012710:Serum Albumin, Bovine / Q000494:pharmacology*; D013075:Sperm Capacitation
D002788:Cholesterol Esters; D008563:Membrane Lipids; D010743:Phospholipids; D012710:Serum Albumin, Bovine; D002784:Cholesterol; D000251:Adenosine Triphosphatases