Effect of Progesterone and Oestradiol on Sperm–zona Binding and Acrosome Reaction in Bovine Spermatozoa after Thawing |
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Authors: | K Lukoseviciute V Bizokas H Zilinskas A Januskauskas |
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Institution: | Animal Reproduction Laboratory, Department of Non-infectius diseases, Lithuanian Veterinary Academy, Kaunas, Lithuania. |
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Abstract: | This study was conducted assess spermatozoa binding capacity to the oocyte in the presence of 0.1 or 0.5 microg/ml progesterone (P4) or a combination of 0.5 microg/ml P4 with 0.1 microg/ml oestradiol (OE). The number of oocyte-bound spermatozoa in the presence of progesterone was significantly higher (p < 0.05 to p < 0.001) when compared with the control samples, that were incubated in the absence of P4. Spermatozoa binding to the zona pellucida (ZP) of the oocyte were concentration-dependent - significantly higher numbers of spermatozoa were bound in the presence of 0.5 microg/ml P4, when compared with that of 0.1 microg/ml P4. Oestradiol at 0.1 microg/ml concentration used impaired the effect of progesterone-mediated sperm-oocyte binding. The incidences of acrosome-reacted (AR) spermatozoa bound to the ZP - following 0, 60, 120 and 180 min. incubation in the presence and absence of 1 microg/ml progesterone was also assessed. Only at 180 min of incubation a higher (p < 0.001) incidence of the AR-spermatozoa was found in sperm-ZP complexes incubated in the presence or absence of progesterone, being 56.5 +/- 11.1 and 43.2 +/- 8.8 % respectively. In conclusion, progesterone enhances the sperm-ZP binding capacity. Progesterone affects the incidences of AR on zona-bound spermatozoa only after prolonged co-culture. |
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