THE HORMONES IN HUMAN REPRODUCTION 



lutea in the ovaries of one sow, when the modal number is 

 present, weigh about 5 grams. By direct extraction the yield 

 of crude progestin is equivalent to 0.05 mg. of progesterone 

 per gram of raw tissue. Therefore one sow having 10 corpora 

 lutea has about 0.25 mg. progesterone in the ovaries at the 

 moment of killing. If the total output per day, estimated in 

 section 3 above as 210 mg., is anywhere near correct, this 

 means that the amount present in the ovaries at any one 

 moment is less than 2 minutes* supply. This is a very impor- 

 tant fact, for it points to a very high rate of "turnover" of 

 secretion in the gland. We must think of the corpus luteum 

 as making the hormone quite rapidly, working up only a 

 Httle at a time but putting it through very quickly. 



5. What is the daily output of the human corpus luteum? 

 The volume of secretory tissue in the human corpus luteum 

 is very difficult to measure, since the gland has a folded wall 

 about a large cavity filled with connective tissue, like the 

 monkey's corpus luteum shown in Plate IX, A. Estimates 

 which I have made by two rough methods give 450 to 500 

 cu. mm. as the volume of secretory tissue in one corpus luteum. 

 This is 150 times the volume of the rabbit's corpus luteum; 

 and assuming once more that the human corpus luteum pro- 

 duces progesterone at the same rate as the rabbit's, volume 

 for volume, then the daily output of the human corpus luteum 

 may be estimated as about 20 milligrams per day. 



This calculated result seems rather high when compared 

 with a few estimates obtained in other ways. For example, 

 Kaulfmann in 1935 reported producing a progestational en- 

 dometrium in a human patient with 50 rabbit units in 15 days. 

 These were presumably Clauberg units, of approximately 0.4 

 mg. each, making the dose about 1.3 mg. daily. Assuming that 

 this is somewhere near the minimum effective dose, and allow- 

 ing for a ratio of about 1 :4, as in the rabbit (section 1 above) 

 between the minimum daily dose for progestational prolifera- 

 tion and the amount necessary to carry out the real task of 



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