title: Evaluation of the effect of 17alphaOH-progesterone and 17beta-oestradiol on human sperm ability to fuse with oocytes: comparison and possible interference with the effect of progesterone.
abstract: The demonstration of a stimulatory effect of progesterone (P) on the sperm/oocyte fusion has provided the most relevant biological evidence of the effect of P on sperm functions involved in fertilization. Some evidence exists that 17alpha-hydroxyprogesterone (17alphaOH-P) and 17beta-oestradiol (17beta-E2), could also exert non-genomic effects on human spermatozoa and a role for 17beta-E2 as a possible physiological modulator of P action on spermatozoa has been suggested. This study aimed to determine the effect of the exposure of human spermatozoa to 17alphaOH-P and 17beta-E2 on sperm/oocyte fusion as well as the possible interference of 17beta-E2 with the effect of P. The effect of steroids on sperm/oocyte fusion was assessed by means of the hamster egg penetration test (HEPT). The exposure of capacitated sperm suspensions to scalar doses of 17alphaOH-P produced a significant enhancement of penetrations/oocytes with a dose/response effect. It was equal to 75.3% of that produced by equimolar doses of P. Conversely, 17beta-E2 (from 100 nM to 50 microM) did not produce any significant effect when added either before or after capacitation. Moreover, the sperm pre-incubation with 17beta-E2 did not interfere with the stimulatory effect of P. These results support a physiological role for 17OH-P in the process of fertilization, but not a role for 17beta-E2 as a possible physiological modulator of P action on spermatozoa.
authors.affiliation: Andrologic Unit, Department of Internal Medicine, University of L'Aquila, L'Aquila, Italy. franceari@cc.univag.it
authors.forename: F
authors.initials: F
authors.lastname: Francavilla
authors.forename: R
authors.initials: R
authors.lastname: Romano
authors.forename: C
authors.initials: C
authors.lastname: Pandolfi
authors.forename: B
authors.initials: B
authors.lastname: Macerola
authors.forename: R
authors.initials: R
authors.lastname: Santucci
authors.forename: S
authors.initials: S
authors.lastname: Necozione
authors.forename: S
authors.initials: S
authors.lastname: Francavilla
mesh_terms: D019326:17-alpha-Hydroxyprogesterone / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D006224:Cricetinae; D004305:Dose-Response Relationship, Drug; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D005306:Fertilization / Q000187:drug effects*; D006801:Humans; D008297:Male; D011374:Progesterone / Q000494:pharmacology; D013075:Sperm Capacitation
chemical_list: D011374:Progesterone; D004958:Estradiol; D019326:17-alpha-Hydroxyprogesterone