Inhibition of Spermatogenesis and Ovulation in Rabbits with Antiovine LH Rabbit Serum.

Abstract

Summary Active immunization of New Zealand White male rabbits with NIH-LH-S₈ and S₁₀ resulted in loss of libido and suppression of semen production. Testes and accessory gland weights were reduced by 80% and pituitary weights were elevated 35%. Histological examination of the testes revealed absence of spermatozoa and spermatids and degeneration of spermatocytes. One mg testosterone on alternate days restored libido but semen production remained suppressed. No significant repair of atrophied testes or accessory organs occurred. The antiserum, concentrated by repeated precipitation with ammonium sulfate, gave an antibody titer of 1:32,000 and reacted with ovine LH, FSH, TSH and possibly STH in the Ouchterlony gel diffusion test. The antiserum used at dosage levels of 3.0 cc to .075 cc blocked ovulation in 13 females mated immediately with a vasectomized male and in four females injected simultaneously with 25 üg exogenous LH. The minimum antiserum dosage required to inhibit ovulation was .075 cc. Results obtained were attributed to neutralization of endogenous gonadotropins. Inhibition of endogenous testosterone was suggested among males.