AGEING OF ELASTIC TISSUE AND THE 

 SYSTEMIC EFFECTS OF ELASTASE 



Albert I. Lansing, ph.d. 



Department of Anatomy, Emory University, Georgia. 



It is interesting to note that although collagenic and 

 elastic fibres have closely related origins, they are remarkably 

 different functionally, chemically, and anatomically. The 

 collagenic fibre is a tough, stretch-resistant element that is 

 quite rich in hydroxyproline and is characterized by regular 

 transverse periodicity. The elastic fibre, as the name indicates, 

 is very elastic, contains only a trace of hydroxyproline and 

 is annoy ingly free of structural characteristics. The latter is 

 especially true of elastic fibre preparations in the electron 

 microscope. A propos of the present discussion it may also 

 be added that these two fibre types differ in their suscepti- 

 bility to pathological alterations; there are a great number of 

 diseases affecting collagen and the generalized fibrosis of 

 ageing is almost a diagnostic feature of that process. On the 

 other hand there are but a limited number of diseases of 

 elastic tissue, and the ageing of this material is highly localized. 

 Hass (1939) has reviewed much of the data concerning 

 elastic tissue diseases. 



In my present discussion it is intended to review some of 

 the data on age changes in arterial elastic tissue and its 

 relation to human arteriosclerosis, and to note that the age 

 changes in dermal elastic tissue of the human are strikingly 

 different from those found in arteries. 



Arteriosclerosis, edited by Cowdry in 1933, reveals a sur- 

 prising unanimity of opinion in regard to the nature of this 

 disease. Fox, in outlining the phylogenetic aspects of arterio- 

 sclerosis, emphasized the significance of changes in the 



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