106 



Mr. E. Mellanby. 



[Oct. 3, 



carbohydrate. Such facts as these render it improbable that creatin 

 excretion is, in any sense, an indication of abnormal carbohydrate metabolism, 

 and it seems to be that the causal relationship commonly held to have been 

 established between these two substances is quite unjustified. The situation 

 can be summed up by the statement that creatin metabolism, together with 

 many other biochemical changes in the organism, goes wrong in the absence 

 of carbohydrate, but, on the other hand, an abnormal creatin metabolism 

 does not mean an abnormal carbohydrate metabolism. 



6. General Considerations. 



There is some evidence that the puerperal excretion of creatin depends 

 upon the action of a substance formed in the mammary gland itself. For 

 instance, it was seen above that the woman who did not suckle her child 

 after parturition excreted an abnormally large proportion of creatin. In 

 such a case, when the mammary gland is not freed of its milk in the 

 normal way, any active substance would undoubtedly be absorbed to excess 

 into the blood-stream from the gland, and an excessive excretion of creatin 

 result. 



Just as the ovum at an early stage of development must produce some 

 potent physiological substance in order to alter the disposition of nutriment 

 in the maternal organism for its own benefit, so the mammary gland, after 

 childbirth, must use equally powerful means to force its claim upon a 

 community of cells, each fighting for the good things distributed by the 

 blood. The potency of the substances formed in the early foetus is evident 

 in the morning sickness and other unpleasant symptoms of pregnancy, 

 while, on the other hand, there is evidence of a similar nature that the 

 mammary glands immediately after childbirth contain physiologically active 

 substances. For instance, the milk fever of cows is a condition for which 

 the mammary glands are largely responsible.* That this is so is evident 

 by the treatment of the condition, a treatment which generally brings about 

 recovery, namely, to inflate the udders with air. Such treatment suppresses 

 the activity. of the mammary gland, and, no doubt, stops the formation of the 

 active toxic substances. 



Somewhat analogous to the milk fever of cows is the very common 

 pyrexia seen in women about the third day after childbirth, more especially 

 in those women where the milk secretion is very abundant and the breasts 

 are congested and tender. It is only by careful evacuation of the breasts 



* Dr. Pembrey informs me that another important factor in milk fever is the state of 

 nutrition of the cows. Pregnant cows which have been overfed are much more liable to 

 milk fever. 



