Carnitine derivatives in hereditary cardiomyopathic animals

BIO 14.6 Syrian hamsters and diabetic KK mice have been reported to develop hereditary cardiomyopathy spontaneously. In order to investigate the pathophysiological role of carnitine metabolism in hereditary cardiomyopathy, tissue levels of carnitine derivatives and the histology of the heart, liver and skeletal muscles from BIO 14.6 hamsters and KK mice were studied. Free carnitine levels in the heart of the BIO 14.6 hamsters (287.0 +/- 27.0 n mole/g wet tissue) were significantly lower than in the control group (348.8 +/- 83.8, p less than 0.05). Short chain acylcarnitine (197.0 +/- 56.0 n mole/g wet tissue) and total carnitine (667.6 +/- 136.4 n mole/g wet tissue) in the hearts of the BIO 14.6 hamsters were significantly lower than in the control group (short: 425.2 +/- 54.8, total: 1023.6 +/- 81.4, p less than 0.001). There was no significant difference in the levels of various carnitine derivatives of the liver and skeletal muscles from the BIO 14.6 hamsters and control hamsters. On the other hand, carnitine derivatives in KK mice did not change significantly compared with those in the heart, liver and skeletal muscles of the control mice. Histological findings showed that heart muscle degeneration and necrosis were found in both cardiomyopathic animals. Coagulative necrosis was found in both animals, whereas myocytolytic necrosis was found only in the BIO 14.6 hamsters. In KK mice, the right ventricle, especially tissue under the epicardium, was severely affected compared with the left ventricle. In the BIO 14.6 hamsters, however, lesions were scattered over both ventricles with a predilection for the left ventricle.