|Lipman Ruth D|
|Smith Donald E|
|Dallal Gerard E|
|Cyr Deana E|
Submitted to: Mechanisms of Aging and Development
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/7/1994
Publication Date: N/A
Citation: N/A Interpretive Summary: Reducing dietary caloric intake is associated with the extension of life span in most animals. In this study, it was demonstrated that restricting the dietary caloric intake of Emory mice results in a 40% extension of life, significant delay in the onset of cataract, and, surprisingly, diminished vitamin C (ascorbate) levels. It was also noted that calorie-restricted animals have better regulation of glucose during aging, vital for the proper function of various systems within the body, and diminished formation of glycoproteins, linked to dysfunction and accumulation of unnecessary altered proteins. Calorie- restricted animals also show prolonged fertility and diminished cancer, but increased levels of DNA and RNA oxidation which is usually associ- ated with shortened lifespan and age-related disease. Results from this study were used to evaluate the relationships between diet, cataract, and other age-related changes.
Technical Abstract: The Emory mouse is the best model for age-related cataract. In this work we compare the effects of feeding a control diet (C) with a diet restricted (R) by 40% relative to C animals. In the R animals, median lifespan was extended 40%. Cataract progression was delayed for the first time, starting at 5 months and continuing throughout life. Ascorbate levels in plasma and liver of R animals were 41-56% of C animals. There was no difference between diet groups with respect to lens ascorbate. Aging was associated with a decrease in ascorbate in lenses and kidneys in C and R mice. Liver glutathione levels were maximal at 12 months. Plasma glucose levels were >27% lower in R animals at 6.5 and 22 months, and there was a 14% increase in glucose levels upon aging for both diet groups. In R mice, glycohemoglobin levels were 51% lower and tail collagen breaktime was decreased by 40%, even in younger animals. Collagen breaktime increased >360% upon aging for both diet groups. Rates of production of urinary oxo**8dG and oxo**8G were higher in R animals as compared with C ani- mals and increased upon aging. C animals exhibited more cancer. Fecundity was extended in R animals. These data allow evaluation of several theories of aging.