THE USE OF STILBESTROL INHIBITED MALES AS TEST ANIMALS FOR GONADOTROPHIC HORMONES

Abstract

In immature male rats and chickens the secretion of pituitary gonadotrophins can be completely inhibited with implants of diethylstilbestrol pellets. These physiologically hypo-physectomized males were found well suited as assay animals for gonadotrophic hormones. They are as sensitive to the gonadotrophins used as are hypophysectomized animals, but have the advantage over the latter in that they are easier to prepare. They live under ordinary laboratory conditions much better than do hypophysectomized animals. Estrogenized male chickens, because they have an easily measurable and externally visible secondary sex character, the comb, are particularly convenient to use. Both qualitative and quantitative assay of gonadotrophins is possible. By considering the changes produced in comb size, testes wts. and testes histology, it is possible to distinguish positively between pure FSH, FSH and LH mixtures and pure LH prepns. and naturally occurring mixtures of these 2 hormones.