GnRH agonist induces apoptosis in seminiferous tubules of immature rats: direct gonadal action.

To investigate direct gonadal effect of buserelin as an agonist of gonadotrophin releasing hormone, the incidence of apoptotic cell death was measured. Thirty 25-day-old immature Wistar male rats were divided into two groups: treated and control rats. Treated rats were given 1.25 mg buserelin acetate/g body weight control rats received vehicle subcutaneously for 5 days. Formalin-fixed paraffin embedded testicles were then investigated for the morphology of seminiferous tubules and occurrence of apoptosis using haematoxylin-eosin staining and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling respectively. Immaturity of rats was proved by the morphological characteristics of testis. In contrast to the control rats, significant increase of apoptotic cell death was found in buserelin-treated rats. Apart from the well-known pituitary-testicular function of buserelin as an agonist of gonadotrophin releasing hormone, our findings suggest that it induces apoptotic cell death via direct gonadal action.