Induction of Ovulation in Rana pipiens by Pituitaries of Triturus viridescens. ∗

Abstract

Since the first report of ovulation induced during the non-breeding season in Rana pipiens by homoplastic anterior pituitary transplants, 1 this species has been used repeatedly for demonstrating and studying this reaction. 2 This form will also ovulate after treatment with pituitaries of other species of Rana, e.g., R. sphenocephala, etc., 3 and of fish, Lepidosteus, 4 and with beef pituitary extract (phyone). 5 There is, however, the report that “mammalian pituitary extract, whole sheep pituitary, and the Antuitrin-S from pregnant human female urine have proven to be entirely ineffectual in respect to ovulation in Rana pipiens” (p. 29 6 ) and more recently negative results followed the use of pregnant mare's serum, Antuitrin-S, beef anterior lobe extract, Antuitrin, live implants and macerated injections of whole glands from fishes (Perca flavescens, Cristovomer nanaycush, Stizostedion vitreum) and from Necturus even when very large doses were used. 7

Because of this apparent refractoriness of Rana pipiens to hetero-plastic anterior pituitary treatment, tests were made in which whole pituitaries of Triturus viridescens were injected into the body cavities of females while others received equivalent amounts of homoplastic pars anterior. In a preliminary test made in December, 1937, in which 4 anterior pituitaries from male Rana Pipiens and 8 whole pituitaries of Triturus viridescens, respectively, were implanted into 2 animals, no ovulation occurred, so larger doses were employed in the succeeding experiments.