Effect of Homologous Spinal Cord in Freund's Adjuvant on Cockerel Comb,Testicular and Body Growth. ∗

Discussion and summary

Injection of homologous spinal cord in Freund's adjuvant into 7-day-old cockerels retards body growth with disproportionate retardation of comb and testicular growth. Preliminary microscopic examination of combs revealed decreased mucoid matrix of the intermediate layer of the dermis in experimental animals, suggesting a hormonal mechanism (1). Freund and co-workers (2) reported production of aspermatogenesis in guinea pigs by injection of homologous testicular tissue and adjuvant. In studying the effects of other tissues, these investigators found mild testicular damage and aspermatogenesis after injecting homologous CNS tissue and adjuvant into guinea pigs. The effects of these injections on secondary sex characteristics were not studied. They believed that, although CNS and testes shared a common antigen, the testicular injury was secondary to physio-pathologic changes associated with meningo-encephalitis (loss of body weight and other symptoms). In our chickens the incidence of encephalomyelitis was very low. Although body weights were retarded in these animals and in animals receiving liver-in-adjuvant, ratio of comb weight to body weight was lower only in the experimental group, indicating a disproportionate retardation of comb growth. It appears that some factor more specific than decreased body weight and changes associated with encephalomyelitis is operative. Whether it is a common antigen shared by CNS tissue and testes or whether it is inhibition of hypothalamic-hypophyseal function is purely speculative.