THE ROLE OF THE PITUITARY GONADOTROPINS 



IN INDUCTION OF OVULATION IN THE 



HYPOPHYSECTOMIZED RAT* 



Frances Carter, Marion C. Woods and Miriam E. Simpson 



Institute of Experimental Biology and Departments of Anatomy 



University of California 



Berkeley and San Francisco 



The experimental induction of ovarian follicular development constitutes no 

 problem. Growth of follicles has been induced in many species by homologous 

 and heterologous gonadotropins. Luteinization of follicles can also be 

 accomphsiied with relative ease, but ova are too often enclosed. 



Monkey 



This was our experience (van Wagenen and Simpson, 22, 26, 27) in efforts 

 made to induce ovulation in the primate (Macaca mulattd). Immediate 

 success was attained in causing follicular growth but the conditions for 

 induction of ovulation were more difficult to determine. Once conditions of 

 timing and dosage were mastered, ovulation was induced after administration 

 of follicle-stimulating hormone (FSH) and interstitial cell-stimulating 

 hormone (ICSH) derived from sheep pituitaries, as well as by monkey 

 pituitary extracts. Ovulation resulted more consistently after administration 

 of preparations from monkey pituitaries, either with or without supplementa- 

 tion by human chorionic gonadotropin (HCG). Both immature and adult 

 females ovulated after injection of appropriate dosage for 7 to 9 days. Adults 

 were injected during the first half of the cycle (from day 5 to 15). Ovulations 

 were multiple in all adults but not in all prepuberal animals. Whether this 

 constitutes a significant difference in the response of the immature monkeys 

 is not yet certain. These observations in the monkey have been adequately 

 documented in the literature. 



Similar procedures have been followed by Gemzell et ah (8, 8a) and by 

 Rosemberg et al. (18) with success in the human female, and recently by 

 Knobil et al. (12) in the hypophysectomized monkey. However, these studies 



* Aided by grants A-800 and RG-4339 from the United States Public Health Service, and 

 by a grant from the Committee on Research, Council of Pharmacy and Chemistry, 

 American Medical Association, and from the Population Council, Inc., New York City. 



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