Increased sarcolemmal membrane permeability of cardiac muscle cells in rats fed grains cultivated in a Keshan disease endemic area: a study with horseradish peroxidase as a tracer.

ABSTRACT

The alteration of sarcolemmal membrane permeability of cardiac muscle cells in rats fed grain from a Keshan disease (KD) endemic area was studied with horseradish peroxidase (HRP) as a tracer. Weanling male rats were divided at random into three groups and fed the following three diets, respectively, for 3 months a diet with grain from a KD endemic area (Group A), a diet with grain from a KD nonendemic area (Group B), and standard laboratory chow (Group C). At the end of the experiment, HRP was injected intravenously and localized in the ventricular myocardium by light microscopy. The experimental results showed that the percentage of cardiac muscle cells containing HRP reaction product in rats fed grain from the KD endemic area was significantly greater than that in rats fed grain from nonendemic area and standard laboratory chow. This suggests that the sarcolemmal membrane permeability of cardiac muscle cells in rats of Group A was markedly increased. The distribution of cardiac muscle cells with increased sarcolemmal membrane permeability was similar to that seen in the myocardium of KD patients. The present study suggests that the abnormal membrane permeability of cardiac muscle cells may play an important role in the pathogenesis of myocardial necrosis in KD.