title: Rapid non-genomic actions of progesterone stimulate Ca2+ influx and the acrosome reaction in human sperm.
abstract: This review summarizes some recent findings in human sperm which show that progesterone and 17 alpha hydroxyprogesterone are able rapidly (within seconds) to elevate [Ca2+]i and elicit the acrosome reaction (AR) via a non-genomic cell surface receptor. Progesterone promotes a transient elevation in [Ca2+]i which is blocked by extracellular La3+ and Ni2+ and removal of extracellular Ca2+ following chelation with EGTA. Some studies suggest that polyamines, trypsin-like proteases, and progesterone receptor aggregation are involved in progesterone-induced Ca2+ influx and AR. The receptor is not stimulated by the potent synthetic progestigins (e.g. promegestone, norethynodrel, megestrol acetate, cyproterone acetate) and is weakly antagonized by the genomic anti-progestins RU 486 and ZK 98.299. The sedative-hypnotic 3 alpha hydroxyl A-ring reduced pregnane steroids, which are powerful activators of the GABAA Cl- channel, are weak activators of Ca2+ influx and the AR. These data suggest that human sperm have a cell surface steroid receptor which is unlike the genomic progesterone receptor and the GABAA Cl- channel steroid receptor.
authors.affiliation: Department of Pharmacology, Eastern Virginia Medical School, Norfolk 23501.
authors.forename: P F
authors.initials: PF
authors.lastname: Blackmore
mesh_terms: D000177:Acrosome / Q000187:drug effects; D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels / Q000378:metabolism; D018118:Chloride Channels / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D017136:Ion Transport / Q000187:drug effects; D008297:Male; D011374:Progesterone / Q000494:pharmacology*; D011963:Receptors, GABA-A / Q000378:metabolism; D011980:Receptors, Progesterone / Q000187:drug effects / Q000378:metabolism; D013094:Spermatozoa / Q000187:drug effects* / Q000378:metabolism*
chemical_list: D015220:Calcium Channels; D018118:Chloride Channels; D011963:Receptors, GABA-A; D011980:Receptors, Progesterone; D011374:Progesterone; D002118:Calcium