General Discussion 55 



say that an individuars likelihood of dying of cancer increases with age. 

 That is an age-specihc change, and I don't think it's right of Prof. 

 Cameron to turn a blind eye to the statistical type of approach. 



Cameron: No, I haven't; I may have turned a half-blind eye. I agree 

 absolutely with you that there isn't an\i:hing specihc but the frequency, 

 and therefore it may be a matter of, say, some co-ordinating system 

 going \\Tong or something like that. Pathologists nowadays are turning 

 more and more to the nervous control of structural changes in tissues, 

 but they do not know very much about it. I couldn't agree more with 

 you on that point of view, but when I read, as I frequently do, about 

 the specific changes of old age, I wonder what they are. 



Lansing: To take further exception to the point that Prof. Cameron 

 makes, manj^ organisms that don't have blood vessels or organized 

 circulatory systems or connective tissue beds to interfere with circula- 

 tion manifest ageing as we know it in man, mice and other organisms. 

 As Heilbrunn {Outline of General Physiology, second ed., Saunders, 

 Phila.) said in his little chapter on ageing, "in the last analysis ageing is a 

 problem of breakdown of cells". Age changes occur in individual cells 

 such as Paramecium and in rotifers and other organisms which lack 

 circulatory or connective tissue systems. 



Shock: I think we are in a dilemma again. Ageing is actually a verb, not 

 a noun. And when we're talking about ageing, we really have to talk 

 about something that is ageing, and this thing varies all the way from 

 individual cells to total animals. Trying, at the present state of know- 

 ledge, to formulate an overall concept that will say all this is apparently 

 beyond us. As I see it, we are faced with the idea that ageing begins at 

 the level of tissues and is most apparent at the level of dealing with the 

 homeostatic adjustment of the entire organism. Although we can talk 

 about the ageing of rotifers and unicellular organisms, in the case of 

 man the information about cellular changes still lies ahead of us. 



Cowdry: I think that the position you take is a good one in the sense 

 tliat ageing results from the vicissitudes of life — that's a position you 

 can't contradict anyway. But I can conceive, and you can too, of the 

 vicissitudes of the life of an epidermal cell — I can also think of those of a 

 cell lining a blood vessel, or of a pancreatic or a gastric cell, because they 

 all have to adjust themselves to alterations in their fluid environments. 

 So that these vicissitudes of life as a factor in ageing are absolutely 

 inseparable from the life of all cells. 



Albertini: There are as many definitions of ageing as opinions. To me 

 it seems very important to know the aim of all these definitions. As 

 physicians it is interesting for us to know why old people are 

 insufficient. We should try to comprehend the cause of the organic 

 insufficiency. I personally think that ageing is the manifestation of a 

 decreasing adaptation caused by loss of tissue and functional reserve. 

 The tissue reserve is always responsible for any loss of functional reserve. 

 Referring to tissue reserve we may distinguish two groups: 



1. Organs with a great tissue reserve but without regeneration, 

 i.e. heart, kidney, lung, brain. 



2. Organs which are able to regenerate, i.e. epidermis. 



