GONADOTROPIC SUBSTANCES 



investigations reported suggest that the quantity of prolan in 

 the blood may remain high in the later months of pregnancy 

 although the urinary excretion of prolan falls. Kennedy 

 (1933) found that there was a progressive increase in the con- 

 centration of prolan in the plasma of pregnant women and 

 that the maximum (about 10,000 "mouse-units" per Hter) 

 was reached in the twenty-fourth week of pregnancy and per- 

 sisted up to the thirty-sixth week. Thereafter, and until 

 term, variable amounts (5,000-10,000 mouse-units per liter) 

 were found. Even i week after delivery as much as 4,500 

 mouse-units per liter could be detected. Kennedy did not 

 estimate the amount of prolan in the urine. It is commonly 

 believed that the "rat-unit" of prolan is considerably smaller 

 than the "mouse-unit"; yet Smith and Smith (1934) men- 

 tioned 500 rat-units per liter as the concentration of prolan 

 in the serum of normal women in the latter months of preg- 

 nancy. They believed that five to ten times as great a con- 

 centration was present in the serum of patients suffering from 

 toxaemia of pregnancy or eclampsia. 



The injection of the cerebrospinal fluid (ventricular, cister- 

 nal, or lumbar) of pregnant women has usually been reported 

 to be without effect on the ovary of the immature rodent 

 (Ehrhardt, 1929; Zondek, 1930; Colombi and Porta, 1934; 

 and Kjellin and Kylin, 1934). Aronowitsch (1930) and Soule 

 and Brown (1932) (normal cases .^) believed that stimulation 

 of the graafian follicle without subsequent luteinization could 

 be produced by the administration of cerebrospinal fluid. 

 Similar effects were produced by Ehrhardt, and Kjellin and 

 Kylin, by injecting the cerebrospinal fluid of pregnant pa- 

 tients with eclampsia or renal disease — an observation in har- 

 mony with the findings of Smith and Smith referred to in the 

 preceding paragraph. 



In 1926 Aschheim reported that prolan could be detected 

 in the placenta both at full term and in very early tubal preg- 

 nancy from which decidual cells were absent. All other re- 



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