Effect of progesterone on bovine sperm capacitation and acrosome reaction.
Progesterone (P) appears to stimulate sperm capacitation and/or induce the acrosome reaction (AR) in some species. In bovine, it is now well established that the BSP-A1/-A2 proteins (the major proteins of bovine seminal plasma) promote sperm capacitation. In this study, we investigated the effect of P on bovine sperm cholesterol efflux, capacitation, and the AR. Labeled bovine epididymal sperm were incubated (0-6 h) with different concentrations of P (0.01-10 microg/ml) in the presence or absence of BSP-A1/-A2 proteins (capacitating conditions). At different time intervals, aliquots of sperm were taken to determine the sperm cholesterol efflux, sperm capacitation (AR induced by lysophosphatidylcholine, lyso-PC), and sperm AR. The results show that the presence of P in the media did not affect the membrane cholesterol efflux potential of the BSP-A1/-A2 proteins. P alone did not stimulate the AR with or without lyso-PC unless the epididymal sperm were incubated in capacitating conditions (in the presence of BSP-A1/-A2). When washed ejaculated sperm were continuously incubated with P, the P did not stimulate AR. However, when ejaculated sperm were preincubated (6 h) with heparin (capacitation medium) and then incubated 15 min with P (2 microg/ml), the percentage of AR obtained was similar to that obtained with lyso-PC. The effect of P on sperm AR was concentration dependent with a maximum 2.2-fold increase at 2 microg/ml of P. These results demonstrate a potential role of P in bovine sperm AR but not in capacitation.
Thérien
Isabelle
I
Department of Medicine, University of Montreal, Montreal, Quebec, Canada H1T 2M4.
Manjunath
Puttaswamy
P
D020101:Acrosome Reaction / Q000187:drug effects* / Q000502:physiology; D000818:Animals; D002417:Cattle; D002470:Cell Survival / Q000187:drug effects; D002784:Cholesterol / Q000378:metabolism; D004542:Ejaculation; D004822:Epididymis / Q000187:drug effects / Q000378:metabolism; D008244:Lysophosphatidylcholines / Q000494:pharmacology; D008297:Male; D011374:Progesterone / Q000494:pharmacology*; D029607:Seminal Vesicle Secretory Proteins / Q000378:metabolism / Q000494:pharmacology; D013075:Sperm Capacitation / Q000187:drug effects* / Q000502:physiology; D013094:Spermatozoa / Q000187:drug effects / Q000502:physiology; D013997:Time Factors
D008244:Lysophosphatidylcholines; D029607:Seminal Vesicle Secretory Proteins; C424303:seminal vesicle secretory protein 109, Bos taurus; D011374:Progesterone; D002784:Cholesterol