Experimental diabetic cardiopathy preventable by insulin treatment.

A quantitative histologic study of hearts from streptozotocin-diabetic and nondiabetic rats was performed. The diabetic rats comprised as group of poorly controlled and one of well-controlled insulin-treated animals. The relative amount of connective tissue was statistically significantly increased in the poorly controlled diabetic rats (p less than 0.01). In the well-controlled group of diabetic rats, the relative amount of connective tissue was the same as in the controls. The number of cells in tunica media of the larger intramural coronary arteries was statistically significantly increased in the diabetic rats in a poorly controlled state (p less than 0.01). There was no difference between the control group and the diabetic rats in a well-controlled metabolic state. Thrombosis or calcification in tunica media of the large intramural coronary arteries was not observed. The present study is reconcilable with the hypothesis of a diabetic cardiopathy and strongly emphasizes the importance of careful insulin treatment.