Abstract
In the last three years immunohistologic methods have successfully been used to localize the hypophysiotrophic (releasing and inhibiting) hormones. The first releasing hormone localized by immunohistologic methods in the guinea pig by LEONARDELLI et al. in 1973 was luteinizing hormone-releasing hormone (LH-RH). The species studied so far for the histologic localization of LH-RH include guinea pig, rat, mouse, duck, toad, cat, dog, and greenfinch (BARRY and CARETTE, 1975; SÉTALÓ, 1976).