ENDOCRINE ARITHMETIC 



the corpus luteum, namely maintenance of pregnancy, then 

 the human corpus luteum would be expected to produce about 

 5 mg. daily. Wiesbader, Smith and Engle of Columbia Uni- 

 versity Medical School (1936) found that a certain effect of 

 the removal of the human corpus luteum (bleeding from the 

 uterus) cannot be prevented by substituting 0.5 mg. daily of 

 progesterone by injection, but can be prevented by 5 mg. 

 This suggests that 5 mg. is a quantity sufficient to produce 

 one of the known effects of the corpus luteum, though not 

 necessarily the full effects. 



Another way of getting at this figure is through the fact 

 that in human females, used-up progesterone leaves the body 

 through the kidneys as sodium pregnanediol glycuronidate, 

 as explained in Chapter V, page 120. Venning and Browne, 

 who discovered this fact, found that if they administered a 

 given quantity of progesterone, they could recover about half 

 of it in the urine as the excretion product. When they collected 

 all the pregnanediol excreted by a patient in a whole men- 

 strual cycle, they found that the total recoverable amount 

 was normally about 60 mg. This would mean about 120 mg. 

 of progesterone actually produced. Since the corpus luteum 

 is probably actively functional during about 10 days of each 

 cycle, we arrive at an estimate of 12 mg. of progesterone pro- 

 duced daily. Another research group, Pratt and Stover of 

 the Henry Ford Hospital, Detroit, obtained considerably 

 smaller values, for their patients yielded only 2 to 3 mg. of 

 pregnanediol daily, which we may consider to represent at the 

 most 6 mg. of progesterone. It is known, however, that the 

 chemical recovery of pregnanediol and estimations of corpus 

 luteum activity based upon this method are subject to nu- 

 merous errors not fully understood. It is perhaps all we 

 should ask for, that the various estimates and calculations 

 we have made and cited fall within limits as close as 5 and 20 

 milligrams per day (Appendix II, note 15). 



Physicians who have used progesterone for disturbances 



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