Metabolic Abnormalities of the Hyperglycemic Obese Zucker Rat

Abstract In a cross-sectional study, we evaluated the metabolic profiles of lean (Fa/?) and obese (fafa) Zucker male rats at 4 to 8 months of age. Although all of the obese rats (N = 108) demonstrated glucose intolerance, most of the obese rats exhibited only mild elevations of fasted and fed plasma glucose. Only 14 of the obese rats were severely hyperglycemic, which resulted in substantial elevations of glyceohemoglobin (GHb) levels. The nerve and lens levels of glucose, sorbitol, and fructose were elevated, and the myo -inositol was depleted in all hyperglycemic obese rats, but not in the euglycemic obese rats. With increasing duration of hyperglycemia, the neural myo -inositol level approached normal, while the lenses became cataractous. All obese rats had increased urinary albumin excretion (UAE), which was dependent on age ( r = .45, P