[Morphometric analysis of myocardial cells in experimental diabetic rats]

Ultrastructure of myocardial cells was studied with a morphometric technique in Wistar rats 6 and 12 months after induction of experimental diabetes with streptozotocin (70 mg/kg i.p.). Weight-matched and untreated rats served as controls. Morphometric analysis showed that volume densities of mitochondria, sarcoplasmic reticulum, lipid droplets and lysosomes were markedly increased and volume density of myofibril was significantly decreased in comparison with those of the control animals. Further measurements of mitochondria indicated that the number density and the transverse profile axis of mitochondria were obviously increased, and inner and cristae membrane surface areas of mitochondria were significantly decreased when compared with the controls. These changes became more serious when diabetic course was prolonged from 6 to 12 months. The results suggest that metabolic disturbances of the myocardial cells in diabetic state may be an important cause of the occurrence of diabetic cardiomyopathy.