Gonadotropic Activity of Amphibian Anterior Pituitary

Abstract

PREVIOUS attempts, using infantile mice or rats as test animals, to demonstrate the presence of a gonadotropic substance in the anterior pituitary of frogs have been entirely negative¹. Since implantation of frog's pituitary into frogs causes ovulation, Zondek comes to the conclusion that the frog's pituitary contains a gonadotropic substance which is inactive in warm-blooded animals. The negative results obtained by Lipschutz and Paez and Zondek were probably due to the fact that the amount of pituitary tissue implanted was too small. Adams and Tukey, however, injected saline suspensions of from 16 to 96 frogs' pituitaries into each infantile mouse and still obtained negative results.