GONADOTROPIC SUBSTANCES 



prolan reaction by implanting placental tissue. No gonado- 

 tropic hormone has been found in the blood, tissues, or secre- 

 tions of any other mammals which have been investigated 

 during pregnancy. ^ In these attempts to demonstrate the 

 presence of prolan, the following tissues and body-fluids have 

 been unsuccessfully studied: blood, urine, amniotic fluid, 

 fetal membranes, milk, saliva, and feces in the cow; urine, 

 amniotic fluid, and fetal membranes in the guinea pig, sheep, 

 and pig; urine and placenta in the rat, rabbit, and cat; urine 

 in the mouse, ferret, goat, dog, lion, tiger, and elephant. 



Changes in the genital tract of female animals following the 

 administration of prolan. — Particularly in the earlier reports 

 on the efi^ects of gonadotropic hormones, little or no distinc- 

 tion was made among preparations of varied origin which 

 caused about the same biological efi^ects. In this section, con- 

 sideration will be limited, as far as possible, to the gonado- 

 tropic effects of placenta, urine, and blood (or extracts of 

 these) obtained from pregnant women. 



At the outset it is necessary to point out that Zondek and 

 many others consider prolan to be a mixture of two gonado- 

 tropic hormones, "prolan A" and "prolan B." "Prolan A" is 

 thought chiefly to stimulate the growth of the graafian folli- 

 cle. "Prolan B" is thought to produce "luteinization" of the 

 granulosa and theca cells of growing or mature follicles; some 

 consider that only theca luteinization will occur if "prolan B" 

 acts on very immature follicles. The relationship of these hy- 

 pothetical substances to ovulation has not been adequately 

 explained. What is the evidence in favor of this hypothesis? 

 In the first place, "prolan A," more or less free from "prolan 

 B," has been secured only from the urine or blood of non- 

 pregnant individuals. When present it probably has orig- 

 inated in the anterior pituitary. Although the origin of pro- 



5 Other reports are by the following: Aschheim and Zondek (1927); Gutman 

 (1930); Hill and Parkes (1931); Kraul (1931); Bruhn (1933); Ehrhardt and Ruhl 

 (1933), KQst (1934); and Maurer (1934). 



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