Viability period of the rabbit skeletal muscle in the Ca ²⁺-induced Ca²⁺ release (CICR) test

Background : In Japan, malignant hyperthermia susceptibility (MHS) is diagnosed by detecting an enhanced rate of CICR from the sarcoplasmic reticulum in skinned skeletal muscle fibers. We usually consider the CICR test should be completed within 48 hours of muscle excision. We measured the viability period of the CICR test in the following four treatment groups. Methods : Muscle bundles prepared from a rabbit were dissected and stored in muscle relaxant solution at -30°C, 4°C, 20°C, and 37°C. The CICR rate was measured in a part of the biopsied muscle using chemically skinned fibers that had been prepared according to Endo's method. Results : With muscle bundles stored at -30°C and 37°C, the rate of CICR could not be measured. Function related CICR of the muscle stored at 4°C and 20°C lasted for four days. Conclusions : This results showed that rate of CICR can be measured for at least 4 days when skeletal muscle bundles of rabbits are stored both at 4°C and at 20°C. Further studies are expected including the optimum conditions on stored temperature and stored days in the human muscle.