INVESTIGATION OF THE IMMUNOCASTRATION EFFICACY AND LONGEVITY OF A SINGLE DOSE GNRH VACCINE IN YOUNG MALE RATS

Conventionally, immunization protocol require an initial priming immunization followed by an antigen boost for adequate immunity and long-term immunization. In this study we were evaluate the immunocastration efficacy and longevity of immunization with a single-dose GnRH vaccine (Repro-Bloc™) in young male rats. Rats in the vaccine group (VAC, n: 35) were treated with GnRH vaccine as single-dose (200 ul) and the control group (C, n: 15) were also injected with saline solution. Blood samples from all rats were taken monthly for 6 months and at 12th month. GnRH antibody titers, testosterone and leptin levels were determined by commercial RIA kits. Rats at 6th and 12th months were sacrificed for histologic analysis of testes. GnRH antibody levels were found similar in the VAC and C groups (P>0.05) at -1 week. As compared to the C, GnRH antibody levels (pg/ml) of the VAC group at 1st, 2nd, 3rd and 4th months rose continuously and reached the peak level at 5th month, decreased at 6th month and increased again by the 12th month (P