The effect of active immunization with gonadotropin releasing hormone conjugate (GnRH-BSA) on gonadosomatic indices (GSI) and sperm parameters in mice

Background: Gonadotropin releasing hormone conjugate (GnRH-BSA) raises antibodies against biologically active gonadotropin releasing hormone (GnRH) which affects body weight, gonadosomatic indices (GSI) and sperm quality in male mice. Objective: The objective of this experimental investigation is to develop an effective and reliable hormonal immunocontraceptive vaccine to suppress spermatogenesis by using GnRH-BSA conjugate. Materials and Methods: Forty sexually mature mice, Mus musculus were divided into two groups of twenty each. Group 1, served as control, while group 2 were immunized at monthly intervals for four times against GnRH with a GnRH-BSA conjugate (50 μg) with aqueous adjuvant (Freund's adjuvant). After 30 days of each immunization, body weight, GSI and sperm quality were observed in the immunized groups and compared with the control group. Results: Body weight showed alterations in immunized animals as compared to control. However, GSI, sperm motility, sperm count and sperm morphology were significantly decreased in immunized animals throughout the experimental investigation and these effects were more prominent and significant in the later part of the experiment. Conclusion: These results suggested that the active immunization against GnRH produced bioeffective antibodies as indicated by significant reduction in GSI level and sperm quality and induced infertility in male mice.