IMPROVEMENT OF CARDIAC-PERFORMANCE AND METABOLISM IN LONG-TERM DIABETES-MELLITUS AFTER TREATMENT WITH INSULIN

Rat hearts induced diabetic by administration of streptozotocin were i nvestigated after 8 months using the isolated perfused working rat hea rt model at a physiological workload of approximately 45 min. They are hemodynamically characterized by a significantly reduced cardiac outp ut (p<0.001) and metabolically by a 49% reduction in glucose utilizati on (p<0.001), mainly caused by reduced glucose uptake (p<0.001) and an increased lactate and pyruvate production (p<0.001), associated with a reduction of oxygen consumption by 44% (p<0.001). Both lead to reduc ed ATP and CP myocardial tissue levels (p<0.001). Similar results with respect to cardiac performance and metabolism are observed already af ter 2 months of diabetes. Treating these rats after 2 months of diabet es with insulin for 6 months, cardiac output (ns), cardiac metabolism (ns), oxygen uptake (ns) as well as ATP and CP levels (ns) are restore d, indicating that normalization of cardiac function in this model dep ends mainly on the restored cardiac metabolism. These findings were as sociated with changes in the angioarchitecture as demonstrated.