THE HORMONES IN HUMAN REPRODUCTION 



begin to grow. Knowledge of this subject goes back to 1928, 

 when Aschheim and Zondek, then of Berlin, found that during 

 pregnancy the human urine contains something that has a 

 powerfully stimulating effect on the ovaries of young mice and 

 rats. This provided the basis for the now famous Aschheim- 

 Zondek test for pregnancy. The urine of a pregnant woman, 

 injected into an infantile mouse or rat, produces prompt and 

 characteristic signs of activity in the ovarian follicles. An 

 even quicker test for pregnancy is provided by a modification 

 of this procedure, introduced by Maurice Friedman, an Amer- 

 ican investigator. In the Friedman test the urine, either raw 

 or partially purified by precipitation with alcohol, is injected 

 into the ear vein of a rabbit. If the patient is pregnant, the 

 rabbit ovulates about 10 hours after the injection. This hor- 

 mone test for pregnancy is (in both variations) probably 

 more nearly infallible than any other biological test used by 

 physicians, for when properly performed it is accurate in 

 better than 98 per cent of all cases. 



The gonadotrophic hormone complex of the urine can also 

 be extracted from the placenta and in all probability is made 

 there. George O. Gey, a tissue culture expert of Baltimore, 

 recently showed that placental tissue growing in his test tubes | 

 was able to produce a gonadotrophic substance. Chemically 

 the urinary gonadotrophic material is protein, like the go- 

 nadotrophic hormone that is produced in the pituitary gland, 

 and indeed it is so much like the latter that it was for a time 

 considered to be identical with it, but clear differences between 

 the two substances have been observed, as evidenced by the de- 

 tails of their effects on animals of various species. The placen- 

 tal gonadotrophic hormone complex appears in the urine in 

 the first month of pregnancy, in sufficient amount to give a 

 positive Aschheim-Zondek or Friedman test. It is present 

 throughout pregnancy, but reaches its greatest amount in the 

 second month and falls off rapidly thereafter. In the Rhesus 

 monkey it is found only between the 18th and the 25 th day. In 



{ 202 ) 



