V.A. prospectus research in aging.

  • United States. Veterans Administration
Date:
[1959]
Catalogue details

Licence: Public Domain Mark

Credit: V.A. prospectus research in aging. Source: Wellcome Collection.

    39/140 (page 29)
    DISCUSSION DR. GERARD: Thank you very much indeed. Practically every major scientific gener- alization turns out sconer or later to have an exception. I am delighted to see that there is an exception to Gerard’s Third Law that the intellectual content of a presentation 1s inversely proportional to the number of slides shown. The Committee member we'd like to have open the discussion of aging at the molecular level is Dr. Wendell Griffith. Will you please, Dr. Griffith ? DR. GRIFFITH: I found it difficult, in thinking about this assignment, to arrive at any very positive statement that one might make regarding the problem of aging at the molecular level. I think you will agree readily, as Dr. Gersh has indicated, that certainly one of the manifestations of aging might well con- sist of changes in the ground substance, particularly the changes that involve ionic charges and colloids and the relation of these to the ions in the environ- ment. Even here one may ask which is the cart and which 1s the horse. It is not easy to think of changes at the molecular level that may be re- lated to aging without at once attempting to associate the changes with alterations in cellular or tissue composition and functions. ‘The overall metabolism of a tissue, connective tissue for example, is certain to be affected by an increase in the mineral components of the intercellular matrix of the tissue and it is possible that a change of this type may be correlated ulti- mately with the aging of the tissue. However, a greater hypothetical deposition of calcium phosphate and of other lime salts in connective tissue in the elderly would represent a change at the tissue rather than at the molecular level. What about changes at the molecular level in the placenta? ‘The bio- chemist thinks of the placenta as a particularly apt material for the study of aging because of the changes which it undergoes with time. One can detect demonstrable and reproducible modifications of chemical reactions in this tissue as, for example, in its ability to form glycogen and to metabolize sugar and these modifications may, perhaps, be defined as changes at the molecular level. Such changes, however, are difficult to apply to the aging of cells generally even though they appear closely related to the aging of ‘the placenta. For instance, one has no hesitation in relating variations in the metabolism of the placental tissue to hormonal controls, yet this is a relationship that is difficult, indeed, to apply to structures such as the red Cell.