Inhibition of human sperm function and mouse fertilization in vitro by an antibody against cation channel of sperm 1: the contraceptive potential of its transmembrane domains and pore region

ObjectiveTo explore the contraceptive potential of the CatSper1 transmembrane domains and pore region in vitro.DesignIn vitro study with human sperm and mouse fertilization.SettingAndrology laboratory of an academic research center.Patient(s) and Animal(s)Normozoospermia and viripotent BALB/c mice.Intervention(s)The specific binding of an anti-CatSper1 IgG antibody (H-300) to CatSper1 was confirmed by Western blot and immunofluorescence. Sperm from humans and mice were incubated with H-300.Main Outcome Measure(s)The effects of H-300 on human sperm progressive motility, abnormal acrosome, hyperactivated motility, and mouse in vitro fertilization rates were analyzed.Result(s)A significant decline in sperm progressive motility was observed after 1, 2, and 4 hours of incubation with H-300; the change was mainly ascribed to the decline of fast progressive motility. Significant inhibition of the hyperactivated motility was observed after 5 hours of incubation with H-300. The incubation of mouse sperm with H-300 before insemination reduced the in vitro fertilization rate to 28% of control levels (72% inhibition).Conclusion(s)CatSper1 may be a potential target for immunocontraception, and the antibody may be a tool to study the function of ion channels in sperm in which relatively fewer methods can be applied.