DIESTRUS AND CORPUS LUTEUM FORMATION IN PERSISTENT ESTROUS RATS BY LUTEINIZING HORMONE AND ANTIGONADOTROPIC SERUM1

Abstract

The occurrence of prolonged periods of estrus was observed in a colony of rats of the Sprague-Dawley stock. About 5% of the rats had estrous periods prolonged 10 days or more. Laparotomies demonstrated that the ovaries were composed of follicles, and vaginal smears showed only cornified cells. The adm. of a purified luteinizing hormone . to 7 persistent estrous rats resulted in formation of corpora lutea and in appearance of vaginal diestrus. Injs. of anti-gonadotrophic serum into 8 rats caused atrophy of the ovaries and appearance of vaginal diestrus. After cessation of injs. of antigonadotrophic serum, a short estrus appeared, followed in turn by diestrus and formation of corpora lutea. If estrogen were injected with the antiserum, formation of corpora lutea was prevented. An hypothesis explaining the factors involved in maintaining such a condition is suggested .