Experimental emetine myopathy: enzyme histochemical, electron microscopic, and immunomorphological studies.

Ipecac, containing emetine hydrochloride, is used by patients with anorexia nervosa to induce vomiting. Its chronic usage may result in a myopathy and a cardiomyopathy, the former marked by cytoplasmic bodies. We studied myopathological changes after daily injections of female Wistar rats with emetine hydrochloride intraperitoneally for periods of 4, 5, 9, and 10 weeks. The extensor digitorum longus muscle and the soleus muscle showed core-like lesions, streaming of the z-discs, nemaline bodies, cytoplasmic bodies, and spheroid cytoplasmic bodies. Immunomorphological studies revealed increased amounts of desmin. During a period of repair, i.e., 2, 4, and 6 weeks after termination of emetine application, these myopathological alterations faded while proliferation of the T-tubular system, i.e., honeycomb structures, was more often prevalent. Pathological features completely disappeared between 6 and 12 weeks of recovery.