AgeinCx of Elastic Tissue 



93 



content is .significant. Certainly there is no significant gain 

 or loss of elastin after the third decade of life. 



The data for the ])ulnionary arteries followed a somewhat 

 different pattern from those of the aortas. During the first 

 three decades of life the media of the pulmonary artery 



q:60 



<50 



Q 

 UJ 



?40 



< 



d30 



20 



10 



D- AORTA (means) 

 •- PULMONARY 





• •*• • 





20 



AGE 



80 



Too 



Fig. 2. Analyses of the elastin content of human aortas and 



pulmonary arteries at various ages. The point for aortas at 10 



years is of doubtful significance because of the small number of 



analyses involved. 



contained slightly less than 31 per cent elastin. This increased 

 slowly but steadily throughout life to 34 per cent in the 

 seventh decade and to almost 37 per cent in the eighth decade. 

 The increase with age of elastin, although small, is statistically 

 significant. 



It would appear then that at least after the second decade of 

 life the elastin content of elastic vessels such as the aorta 

 and pulmonary artery either remains constant or actually 



