title: Effect of steroid hormones on membrane sugar transport in human spermatozoa.
abstract: Using the model of exchange transport, we found that glucose transport through the human spermatozoa membrane (447 +/- 54 pmoles/min/10(8) cells) is probably the rate-limiting step in sugar utilization. Sugar transport was more efficient for glucose than for fructose (182 +/- 32 pmoles/min/10(8) cells) and depends on a highly asymmetric carrier with at least two transporting sites. Transport was drastically dependent on pH with an optimal pH of 7.4, showing a decrease of more than 60% with a change of 1 pH unit. Testosterone and 17-B estradiol increased the amount of transported sugar (619 +/- 73 and 922 +/- 110 pmoles/min/10(8) cells, respectively), while progesterone has no effect.
mesh_terms: D001693:Biological Transport, Active / Q000187:drug effects; D002352:Carrier Proteins / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D004958:Estradiol / Q000494:pharmacology*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008297:Male; D009004:Monosaccharide Transport Proteins; D011374:Progesterone / Q000494:pharmacology; D013094:Spermatozoa / Q000187:drug effects / Q000378:metabolism*; D013739:Testosterone / Q000494:pharmacology*
chemical_list: D002352:Carrier Proteins; D009004:Monosaccharide Transport Proteins; D013739:Testosterone; D011374:Progesterone; D004958:Estradiol