ENDOCRINE ARITHMETIC 



It becomes important for our present calculations to kjiow 

 just how much more effective this method is, dose for dose, 

 than injections, because our estimate of the daily need for 

 estrogenic hormone is based on comparison with injected 

 doses. At first sight the results obtained by pellets seem to be 

 achieved by very small doses indeed, and it is generally taken 

 for granted that the method is much more effective than injec- 

 tion. Very little, however, is known about the exact compari- 

 son by actual experiment. Carl G. Hartman has reported, for 

 instance, that the sex skin of a Rhesus monkey was kept red 

 and swollen for 4 months with a single 3-milligram pellet of 

 estrone. This seems small, but assuming that the pellet was 

 entirely used up, this gives a daily dose of 0.025 mg. or 250 

 international units (3 mg. divided by 120 days). Hartman's 

 monkey thus actually received a larger daily dose than is 

 called for on the basis of our estimate, namely 200 interna- 

 tional units. 



Deanesly and Parkes of London, who introduced the pellet 

 method, cite an experiment with one of the male hormones 

 which indicates that the dose by pellet is about one-half that 

 by injection. I have heard of experiments with another male 

 hormone in which the ratio was 2 to 3. If any such proportion 

 as these is true of estrone, then our calculated daily output of 

 estrogen by the monkey is roughly one-third to one-half too 

 large. 



But here again we are guessing. What evidence is there 

 that absorption from a pellet is really comparable to the 

 natural absorption of the animal's own hormone from the 

 ovarian cells? Nobody knows the answer to this. It might 

 even be true that the pellets yield their substance to the blood 

 stream more easily than do the cells of endocrine glands, in 

 which the hormone is made and stored within the cellular sub- 

 stance. The big molecules of the hormone have to make their 

 way through the outer layers of the cell, not merely drop off 

 the surface of a pellet. 



{ 193 ) 



