Biochemical Evidence of Ageing in the Placenta 133 



Glycogen Content and Metabolism 



The glycogen content of the placenta was estimated by the 

 method of Walaas and Walaas (1950). The glycogen was 

 isolated and purified, hydrolysed to glucose, and the glucose 



50 



40 



50 



20 





\. 



• \ 

 \ 



10 IS 20 25 50 



WEEKS OF PREGNANCY 



55 



40 



Fig. 3. The glycogen content, expressed as mg. of 

 glycogen per g. of dry weight of tissue, of the pla- 

 centa as a function of age. The arrow at 40 weeks 

 indicates the range of the values for term placenta. 



was measured by the method of Nelson (1914). There is a 

 marked decrease in the glycogen content of the placenta with 

 age from 6 until 25 or so weeks of age (Fig. 3). The glycogen 

 content remains essentially constant during the last 12 to 15 

 weeks of pregnancy. 



From the measurements of glycogen content before and 



