The Role of the Pituitary Gonadotropins 



11 



ova were released. From this we proceeded on the assumption that the 

 presence of ICSH is of more importance during preparation of the follicles 

 than it is in the ovulatory supplement. 



Table 12. Pilot Experiment. Recombination of Two Purified FSH Preparations 

 WITH 10% ICSH, IN Different Phases of the Ovulatory Treatment 



Table 13 shows a more careful analysis, which confirms the importance of 

 the presence of 10% ICSH during preparation of follicles. Six FSH prepara- 

 tions were tested; for preparation of the follicles each was injected alone in 

 4 RU total dose, and after addition of 10% ICSH. The respective FSH under 

 examination was given alone as the supplement to all groups. Neither the 

 purified FSH preparations given alone nor those to which 10% ICSH was 

 added caused ovulation without supplementation. FSH alone followed by 

 the respective FSH as supplement on the 4th day gave variable results; some 

 FSH preparations caused all rats to ovulate whereas others resulted in 

 ovulation in as few as 30%. The same FSH preparations, upon the addition 

 of 10% ICSH during the preparatory period caused ovulation in most 

 groups when supplemented by the respective FSH. Both the number of rats 

 ovulating and the numbers of ova shed were in most instances greater than 

 when the follicles had been prepared by FSH without the addition of 10% 

 ICSH. The number of purified FSH preparations used and the size of the 

 groups tested seem adequate to establish that more ICSH is needed during 

 follicular growth than is provided by the purest FSH preparations. 



It should not be concluded from the data presented that the proportion 

 of ICSH used (10%) was that most favorable for ovulation. The proportion 

 of FSH and ICSH occurring naturally differs in the pituitaries of various 

 species. The rat pituitary is high in ICSH, certainly far higher than the 

 purified FSH preparations from sheep pituitary. In turning to an analysis 



