BLOOD-GLUCOSE AND INSULIN ARE MODIFIED BY LEVELS OF DIETARY IRON IN COPPER-DEFICIENT RATS

The present study was designed to test the hypothesis that lowering of hepatic iron in copper-deficient rats fed fructose will modify plasma insulin and glucose. One hundred ninety-two weanling male rats were r andomly assigned to eight dietary groups. These diets contained either starch or fructose, adequate or inadequate copper and adequate or low iron. Rats were fed their respective diets for 2 weeks. Following an overnight fast rats were given oral glucose loads (250 mg glucose/100 g body weight). Blood was collected at fasting and at 30, 60 and 120 m in post-load. Rats that had been fed the low-iron diet tolerated oral glucose load better than those fed the adequate-iron diet. These respo nses, however, were not due solely to decreased iron intake, but to a combination of low-iron and low copper intake and/or fructose feeding with low iron intake. The reduced levels of hepatic and pancreatic iro n were accompanied by elevations of copper levels. Fructose-fed, coppe r-deficient rats benefited from these changes by improving insulin eff iciency. (C) 1997 Wiley-Liss, Inc.