Histopathological changes in reproductive organs of male Wistar rats following active immunization against LHRH.

Histopathological changes induced by immune responses generated against luteinizing hormone releasing hormone (LHRH) were studied in adult male Wistar rats. Active immunization with a semisynthetic anti-LHRH vaccine, LHRH D-Lys6, (10, 40, and 80 micrograms/animal) conjugated with diphtheria toxoid, produced bioeffective antibodies as indicated by significant reduction in circulating testosterone levels. At the 14th week after immunization the animals were sacrificed and reproductive organs were evaluated. These organs were studied for histopathological changes and compared with those of nonimmunized control rats. Marked hypoplastic changes were observed in the genital organs. Testicular changes such as arrest of spermatogenesis at the spermatocyte level and atrophic changes in the interstitial Leydig cells were noticed in treated animals. Similarly attenuation of secretory epithelial cells with substantial increase in the stromal tissues was observed in the prostate and seminal vesicles. The current observation suggests the possible usefulness of this anti-LHRH vaccine under clinical conditions where reduction in androgenic response is desired as in the case of hormone-dependent prostatic carcinoma.