PRESERVATION OF TISSUE IN VITRO 

 FOR THE STUDY OF AGEING 



A. S. Parkes, Sc.d., f.r.s. 



National Institute for Medical Research, London. 



The general question of ageing of parts of the body in 

 relation to ageing of the whole can be investigated in various 

 ways. I want to deal with a specialized development of one 

 of them. In the case of organs or tissues which can be grafted 

 it is possible to transfer the organ or the tissue from one 

 animal to another in such a way as to have an old tissue in 

 a young animal or a young tissue in an old animal. Theoreti- 

 cally, as Dr. Krohn has indicated, it is thus possible to 

 distinguish between functional breakdown of a tissue due to 

 internal causes and due to failure of its environment. Unfor- 

 tunately, some of the organs most suitable for homografting 

 and for estimation of functional activity — the endocrine 

 organs other than the pituitary body — are of limited signi- 

 ficance in this connection, because they are known to be 

 dependent on environmental stimulation, and, in the case of 

 the gametogenic function of the ovary, to be of limited 

 potentiality. Nevertheless, instructive results could be 

 expected, especially where successive passages of the same 

 tissue from old animals to young animals as each host becomes 

 senile makes it possible to secure a big difference between tissue 

 age and body age. All such experiments, however, require 

 that the part shall be subjected to the hazards of homografting. 

 I want now to discuss a recently developed technique which 

 permits of experiments where the part is physiologically 

 younger than the whole without the hazards of homografting 

 from a young animal to a contemporaneously older one. 



I refer, of course, to the technique of low temperature 

 preservation by which tissue can be held in a state of sus- 

 pended but potential viability, free from the complications 



102 



