Ageing of Elastic Tissue 09 



a matrix material which together make up the elastie 

 fibre. 



In a recent study of the i)hyl()i^enetic distribution of 

 elastase, Lansing, Rosenthal and Alex (11)53) not only found 

 this enzyme in a teleost fish but also determined that it 

 was present in the islet rather than acinar tissue. Lophius 

 piscatorkis (goose, monk, angler fish) like several other 

 teleosts has islet tissue that is anatomically separate from the 

 acinar portion of the pancreas. Each, then, can be collected 

 separately and in relatively pure form. We found the elastase 

 activity to be confined exclusively to the islet tissue and were 

 thus led to suspect that elastase has a systemic rather than 

 digestive function. This suspicion is supported by the w^ell- 

 known observation that elastic fibres resist digestion in the 

 alimentary tract; adult human pancreatic juice has failed to 

 show elastase activity; the yield of elastase from whole 

 pancreas is extremely low; and beef pancreas is an excellent 

 source of elastase. Since this animal is herbivorous there 

 would appear to be no need for a digestive enzyme for elastic 

 tissue. 



Balo and Banga have recently indicated (1953) that the 

 elastase content of the pancreas of human arteriosclerotics is 

 substantially less than normal. Close inspection of their 

 tabular data shows that age is as much a variable in their 

 material as is arteriosclerosis. For example, the group of 

 arteriosclerotics w^hich yield a mean of 9 elastase units per 

 gram had an average age of sixty-one years; the group of 

 non-arteriosclerotics who came to autopsy because of other 

 diseases had an average age of thirty-four years and a mean 

 of 155 elastase units per gram; lastly, the group of non- 

 arteriosclerotics w^ho came to autopsy through violent death 

 had an average age of thirty-one years and 208 elastase units 

 per gram. The possibility appears to exist that loss of elastase 

 may be related to arteriosclerosis and/or ageing. 



Although elastase has been crystallized by a rather labor- 

 ious procedure with a very low yield, this material is generally 

 prepared as little more than a pancreatic extract by acid 



