Molecular Biology Commons^™

Progesterone And 17 Α-Hydroxyprogesterone: Novel Stimulators Of Calcium Influx In Human Sperm, Peter F. Blackmore, Stephen J. Beebe, Douglas R. Danforth, Nancy Alexander

Bioelectrics Publications

Progesterone and 17 alpha-hydroxyprogesterone (but not other steroids such as testosterone, corticosterone, beta-estradiol, estrone, dehydroepiandrosterone, 20 alpha-hydroxypregnen-3-one, androstenedione, and pregnenolone) were shown to cause an immediate increase, in free cytosolic calcium ([Ca2+]i) in both capacitated and noncapacitated human sperm, using the fluorescent indicator fura 2. Significant increases in [Ca2+]i were observed with 10 ng/ml progesterone, while maximum effects were seen with 1 microgram/ml progesterone. Two other steroids 11 beta-hydroxyprogesterone and 5 alpha-pregnane-3,20-dione exhibited significant activity to increase [Ca2+]i. This increase in [Ca2+]i elicited by progesterone was entirely due to Ca2+ influx from the extracellular medium since the increase in [Ca2+]i …