Protein glycation in the aging male Sprague-Dawley rat: Effects of antiaging diet restrictions

Protein glycation and accumulation of advanced glycosylated end-products (AGEs) are supposed to play art important role in the process of aging. Dietary restriction increases life span and delays the onset of most age-associated diseases. Age-dependent changes in glucose homeostasis and glycated plasma proteins and hemoglobin were determined, and AGEs formation was measured as fluorescence in skin and aortic collagens in male Sprague-Dawley mts fed ad libitum or subjected to every-other-day feeding or JOS food restriction. In aging control mts, skirr and aortic collagen-linked fluorescence increased with a similar exponential curve (aortic values being always higher), whereas glycated plasma protein and hemoglobin decreased slightly. Dietary restrictions decreased glycated plasma proteins and fluorescent products in skin collagen of younger but not older mts, and did not affect glycated hemoglobin or aortic collagen fluorescence. In conclusion, our data indicate that age-related changes in glucose homeostasis do not play a substantial role ill aging; and collagen-linked fluorescence increases significantly during aging, but it may not be sensitive to dietary intervention.