92 



Albert I. Lansing 



Constancy with age of human arterial elastin 



A total of 110 human aortas and 106 human puhiionary 

 arteries from which both intima and adventitia had been 

 removed by stripping were analysed for elastin content by 

 the method just outlined. 



The results obtained by these procedures on aortas ranging 

 in age from stillborn to one hundred and three years are 



90 



80 



70 



>- 50 



I 40 



Z 



5 ^ 



o 

 cc 



u 

 «^ 20 



10 



10 



15 



■35 — -to — tS — ^3 — 55" 



20 25 30 

 MINUTES 



Fk;. 1 . Hydrolysis of human aortas in • 1 n XaOH showing that 



incubation at 98° C. for at least 45 minutes is needed to procure 



a constant residuum of insoluble elastin. 



60 



summarized in Fig. 2. The average elastin content of the 

 media during the first two decades of life is slightly over 

 48 per cent while the average elastin content in the third 

 decade and thereafter drops to values ranging between 41-1 

 and 44 • 1 per cent. Because of the limited number of specimens 

 available for analj^sis in the first two decades it is difficult 

 to decide whether or not this apparent drop in medial elastin 



