The effects of insulin-like growth factor I (IGF-I) complex from seminal plasma on capacitation, membrane integrity and DNA fragmentation in goat spermatozoa

To evaluate the effects of the insulin-like growth factor I (IGF-I) complex from seminal plasma on capacitation, membrane integrity and DNA fragmentation.MethodsA total of 0.5 mL of fresh semen was added to 1 mL of Bracket–Oliphant (BO) medium, and the sample was then centrifuged at a speed of 1 800 rpm for 10 min. The samples were analyzed before and after centrifugation for sperm viability, motility, membrane integrity and capacitation. The centrifuged samples were divided into three groups, each consisting of 3 × 106 spermatozoa. BO medium was added to group 1, BO + 12 ng IGF-I complex medium was added to group 2, and 12 ng IGF-I complex was added to group 3. Then, the samples were incubated for 15 min.ResultsThe result showed that sperm motility, viability and membrane integrity were significantly higher (P < 0.05) after centrifugation. Furthermore, the sperm capacitation was significantly lower (P < 0.05) after centrifugation. The percentages of sperm capacitation, membrane integrity and DNA fragmentation were significantly different (P < 0.05) in all media, including BO, BO + IGF-I complex and the IGF-I complex alone.ConclusionsSperm quality include motility, viability and membrane integrity were lower after centrifugation. Whereas DNA fragmentation after incubation in the IGF-I complex medium also was lower compared to that of specimens in the BO and BO + IGF-I complex media.