Ultrastructural changes of muscle in malignant hyperthermia

Abstract

The ultrastructure of muscles was investigated in 3 cases of malignant hyperthermia. Biopsies were performed in 2 cases during the acute stage, 2 1 2 and 3 hr respectively after the onset of symptoms. These cases proved fatal. In the third case the biopsies were taken 10 hr and 4 months after the onset of the condition, and appeared to be normal. The structural changes in 2 cases included rupture of the mitochondria and the appearance of membranous bodies, increase of sarcoplasmic fluid, dilated sarcoplasmic reticulum and decrease of glycogen granules. In addition crystalline inclusions formed of particles 140 Å in diameter were observed in many muscle fibres. © 1973.