ENDOCRINE ARITHMETIC 



THE RATE OF SECRETION OF ESTROGENIC 

 HORMONE 



It is not possible at present to estimate the rate of secretion 

 of estrogenic hormone with anything like the fullness and 

 probability with which such an estimate could be made re- 

 garding the corpus luteum. As pointed out in Chapter III, 

 the cells which produce the estrogenic hormone are probably 

 scattered throughout the ovary in the walls of small and large 

 follicles. The number and the total volume of these cells is 

 obviously not subject to computation, and therefore the best 

 we can do is to estimate the activity of the ovaries as a whole. 

 I shall give here a summary of such an estimation which was 

 published recently in more technical form elsewhere. As in 

 the case of the corpus luteum, we get our answer by finding 

 out how much of the hormone we need to administer in order 

 to restore one or another of the functional effects of the 

 ovaries after they have been removed. 



How much estrogen is required daily by the monkey? As 

 described in Chapter VI, removal of the ovaries of the Rhesus 

 monkey causes menstruation-like bleeding from the uterus due 

 to removal of the source of estrogenic hormone. If we take 

 out the ovaries and then administer estrogenic hormone, we 

 can try various doses and discover how much we have to give 

 to prevent bleeding. This amount will represent the replace- 

 ment of the hormone formerly produced by the ovaries when 

 they were present. In my notebooks there are records of twelve 

 experiments of this kind which are suitable for our present 

 consideration. In each of them the animals received 125 inter- 

 national units of estrone daily, beginning the day the ovaries 

 were removed. Of these, 4 bled from the uterus beginning on 

 various days from the 3d to the 14th after the operation, in 

 spite of the treatment with estrone. Seven did not bleed at all 

 during the 15 days of the experiment. One, which received a 

 larger dose of estrone, namely 500 international units, showed 



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