GONADOTROPIC SUBSTANCES 



and rendered its transplantation very difficult. ^^ Exactly op- 

 posite results with a different tumor were obtained by Wiesner 

 and Haddow (1933), who reported that the Jensen sarcoma 

 grew more rapidly in rats receiving prolan. 



THE DETECTION AND ASSAY OF PROLAN 



In relatively few reports in the literature on prolan has 

 any attempt been made to refine the assay technique. The 

 ordinary tests for prolan are of little use other than as qualita- 

 tive tests for its presence and hardly deserve to be designated 

 as "mouse-units" or "rat-units." Even less trustworthy are 

 some of the statements as to the relative quantities of "pro- 

 lan A" and "prolan B" in pregnancy-urine or samples or 

 prolan. Only a few of the more important of fifty-odd papers 

 dealing partly or entirely with the assay of prolan will be 

 considered in this section. 



In their first papers on the assay of prolan, Aschheim and 

 Zondek (1927, 1928) injected the material into immature 

 female mice. They ascribed three effects, or combinations of 

 these, to the injection of prolan: (i) follicular growth and 

 maturation; (2) hemorrhage into follicles; and (3) formation 

 of corpora lutea. They maintained that the conclusive dem- 

 onstration of the presence of prolan demanded the production 

 of reactions (2) and/or (3). Subsequently, numerous other 

 techniques, such as those using the following criteria, have 

 been recommended: 



1. Indirect effects (opening of vaginal orifice and oestrus, thickness of 

 uterine wall) in immature female mice and rats. 



2. Effects on the ovaries of immature female rats. 



3. Indirect effects (particularly, hypertrophy of the seminal vesicles) in 

 immature male mice and rats. 



4. Ovulation in the rabbit. 



5. Ovulation in the toad. (Bellerby, and Shapiro and Zwarenstein, 1934). 



^* According to Engel (1934), the inhibition of the growth of this tumor by the 

 injection of prolan is greater if an extract of the epiphysis is also administered. Also 

 see Krehbiel and others (1934). 



[^-17] 



