Effect of choline and methionine treatment on cardiac dysfunction of diabetic rats

There is an abnormal lipid accumulation in the myocardium that might be involved in the congestive heart failure frequently associated with individuals with diabetes mellitus. Because choline and methionine have been reported to modify the incidence of myocardial necrosis in rats fed various fat diets, we decided in our study to assess their effect on the cardiac dysfunction of diabetic rats. Female Wistar rats were made diabetic with streptozocin (STZ, 55 mg/kg i.v.). One week after diabetes induction, one group received choline (0.3 mg/ml), another received methionine (0.25 mg/ml), a third received a combination of the same doses of choline and methionine, and a fourth received neither of these agents; all were administered in the drinking water. Animals were treated for 7 wk. Insulin levels were lower and glucose values higher in the serum of STZ rats relative to controls. Serum cholesterol and triglycerides were significantly elevated in all diabetic animals, and they were also elevated (P less than .05) in the hearts of untreated diabetics. In contrast, the myocardial values of the same lipids were drastically reduced in the treated diabetic animals. Cardiac performance was depressed in all STZ animals, but there was a significant improvement in heart function in treated diabetics relative to untreated ones. Thus, it appears that the buildup of cholesterol and triglycerides in the myocardium are important contributors to the cardiac dysfunction that frequently accompanies diabetes mellitus.