108 



Mr. E. Mellanby. 



[Oct. 3, 



(1) Where the creatinin excreted is normal, as in pregnancy, the puerperal 

 period, and childhood. 



(2) Where the creatinin excreted is markedly subnormal, as in starvation 

 and cancer of the liver. 



In the first cases the muscle apparently retains its normal nutrition, and 

 in the second cases there is rapid wasting. In fact, it seems likely that 

 creatinin excretion is both an indication and a measure of the transport of 

 material from the liver to the muscles. When this transport breaks clown 

 completely, as in carbohydrate deficiency, or when nutrient material is 

 shunted off to supply a neoplasm in the liver, or a growing foetus, or a 

 developing mammary gland, then creatin is excreted. It is, at least, safe to 

 say that most of the recent evidence of the part played by creatin and 

 chemically allied substances which go to form the group known as 

 " extractives " tends to show that they are concerned with the direction of 

 nutritional transport and tissue synthesis, and that they are neither the 

 source nor an indication of katabolic energy changes, as it has been so long 

 supposed. As for the early period of lactation considered in this paper, the 

 evidence leads one to believe that, in a normal suckling woman, whereas the 

 creatinin excreted indicates the condition of nutrition of her muscles, the 

 creatin excreted is a measure of nutriment conveyed to her mammary glands. 



7. Summary. 



In addition to confirming previous workers as to the mode of excretion of 

 nitrogen by women after childbirth, the following new facts have been 

 brought forward : — 



1. The excretion of creatin by women, post partum, does not depend upon 

 the involution of the uterus. It was shown that a woman delivered by 

 Caesarian section, and whose uterus was removed at the time of operation, 

 excreted more creatin than another Caesarian section case whose uterus was 

 left intact. 



2. Babbits do not excrete creatin at this period. The explanation is not 

 obvious. Eating the placenta does not explain the difference, for a cow, 

 after having eaten its placenta, excreted large quantities of creatin. 



3. A metabolic study of parturient women on creatin-free diets indicates 

 that the creatin excretion at this time has some relation to mammary gland 

 activity. 



(a) There is a gradual increase in the ratio in the first few days 



creatinin 



after delivery, corresponding with the increased mammary gland activity and 

 the development of milk from colostrum. 



