Change with age of UV absorbance and fluorescence of collagen and accumulation of epsilon-hexosyllysine in collagen from Wistar rats living on different food restriction regimes.
Accumulation of glycation products (as revealed by the thiobarbituric test and hexosyllysine assay) and the pigmented products (350 nm UV absorbance and 370ex/440em nm fluorescence) in aortal and skin collagen was investigated under the conditions of different nutritional regimes. Four groups of animals were tested: (1) ad libitum fed controls, (2) animals which were food restricted throughout their whole life (50% food intake), (3) animals fed ad libitum during their first year of life and then food restricted and (4) animals food restricted when young and fed ad libitum from the age of 1 year onwards. It was shown that all food-restricted animals showed lower levels of glycation and pigmentation products in collagen preparations from skin and aorta. The lowest accumulation was observed in group 4 which exhibited the longest 50% survival (29.4 months, as compared with 18.3 months in normally-fed controls). Of particular interest is the fact that in this group the decreased rate of accumulation of the glycated and pigmented products was preserved even after 1 year of life, i.e., when the animals had a free access to food. Though not directly supporting the glycation theory of aging (Cerami, 1985), our data are indicative of the involvement of glucose metabolism in the ageing process. Correlation between the levels of glycated and pigmented products in aortal and skin collagen as well as the correlation between the rate of accumulation of these products and 50% survival was impossible to establish. Nevertheless, each time that food restriction was imposed on the animals it always resulted in decreased accumulation of glycated and pigmented products and increased 50% survival. Possible mechanisms for this process are discussed.
Miksik
I
I
Institute of Physiology, Czechoslovak Academy of Sciences, Prague.
Struzinsky
R
R
Deyl
Z
Z
D000375:Aging / Q000378:metabolism*; D000818:Animals; D001013:Aorta, Thoracic / Q000378:metabolism; D003094:Collagen / Q000378:metabolism*; D005508:Food Deprivation / Q000502:physiology*; D006031:Glycosylation; D006601:Hexoses / Q000378:metabolism; D008136:Longevity; D008239:Lysine / Q000031:analogs & derivatives / Q000378:metabolism; D010858:Pigmentation / Q000502:physiology; D051381:Rats; D011919:Rats, Inbred Strains; D012867:Skin / Q000378:metabolism; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet
D006601:Hexoses; D003094:Collagen; D008239:Lysine