Food restriction prevents advanced glycation end product accumulation and retards kidney aging in lean rats

Tissue content of advanced glycation end products (AGE) increases with age and contributes to the changes in structure and function of the renal and c ardiovascular systems. The effect of chronic food restriction on this AGE a ccumulation was investigated in lean WAG/Rij rats. A 30% food restriction p erformed from 10 to 30 mo in female rats reduced their mean body weight fro m 240 +/- 7 to 160 +/- 12 g, but did not modify their survival. AGE collage n content increased from 14.3 +/- 5.5 to 101.7 +/- 13.0 arbitrary units per microgram (AU/mu g) of hydroxyproline (OHPro) in kidney between 10 and 30 mo, and from 9.7 +/- 1,2 to 310.6 +/- 34.6 AU/mu g OHPro in the abdominal a orta. Food restriction reduced AGE accumulation to 21.4 +/- 3.3 and 74.6 +/ - 16.5 AU/mu g OHPro in kidney and aorta of 30-mo-old animals. Similar resu lts were found for collagen prepared from isolated glomeruli (7.8 +/- 1.2, 81.2 +/- 16.1, and 10.3 +/- 4.3 AU/mu g OHPro in 10-mo, 30-mo, and restrict ed 30-mo-old rats). Reduction of intrarenal and arterial AGE accumulation b y food restriction was confirmed by immunostaining in optical microscopy. A ge-related changes in arterial and kidney structures as polyuria and protei nuria were mainly prevented by food restriction. These data indicate that c hronic food restriction reduces the accumulation of AGE and preserves the s tructure and function of the renal and cardiovascular systems in lean rats, although it did not affect survival of the animals between 10 and 30 mo.