RYANODINE RECEPTORS AND THEIR ROLE IN GENETIC-DISEASES (REVIEW)

The skeletal muscle ryanodine receptor (RYR1) is a calcium release cha nnel that mediates efflux of calcium ions from the sarcoplasmic reticu lum into the myoplasm during excitation-contraction coupling. Mutation s in the RYR1 gene have been detected in about 50% of the patients suf fering from malignant hyperthermia (MH), but evidence is accumulating that other genetic defects can also lead to MH in humans. MI-I is a li fe-threatening disorder induced by exposure to volatile anesthetics an d/or the muscle relaxans succinylcholin during surgical procedures in affected patients. MH leads to skeletal muscle rigidity, hypermetaboli sm and rapid rise in body temperature. MH is also known in pigs where it is triggered by stress and therefore often referred to as porcine s tress syndrome. The existence of an animal model has greatly faciliate d the elucidation of the basis for the human disease. This review desc ribes recent advances in the understanding of the physiological action of ryanodine receptors and new insights regarding the relation betwee n different RYR1 mutations and distinct phenotypical appearances.