title: Calcium accumulation by sarcoplasmic reticulum in whole muscle homogenate preparations of malignant hyperthermia diagnostic patients and pigs.
abstract: Calcium accumulation by the sarcoplasmic reticulum in whole muscle homogenate preparations of malignant hyperthermia-susceptible (MH+) and non-susceptible (MH-) humans and pigs was investigated using a calcium electrode at 35 degrees C. Sarcoplasmic reticulum of MH+ humans and pigs showed normal Ca2+ accumulation, with no difference being observed in the rate and the time taken to achieve maximal accumulation. However, the capacity for Ca2+ accumulation by the sarcoplasmic reticulum in MH+ humans and pigs is considerably less stable than normal after prolonged ageing of the whole muscle homogenate preparations in ice. In MH+ patients, the capacity for Ca2+ accumulation by the sarcoplasmic reticulum showed a decline of 62% at 22 h ageing and 70% at 48 h ageing, as compared with a reduction of only 23% in MH- patients. In MH+ pigs, the sarcoplasmic reticulum showed a 96% deterioration in the capacity for Ca2+ accumulation as compared with a loss of only 40% in MH- pigs at 7 h ageing in ice. In both humans and pigs, the decline in Ca2+ accumulation was prevented by incubating the whole muscle homogenate preparations for 2 h at 35 degrees C prior to ageing the preparations. The diminished Ca2+ accumulating capacity of the sarcoplasmic reticulum in whole muscle homogenate preparations of MH-susceptible individuals in our experimental protocol provides a potential diagnostic test for malignant hyperthermia susceptibility.
authors.affiliation: Department of Anesthesiology, Hahnemann University, Philadelphia.
authors.forename: K S
authors.initials: KS
authors.lastname: Cheah
authors.forename: A M
authors.initials: AM
authors.lastname: Cheah
authors.forename: J E
authors.initials: JE
authors.lastname: Fletcher
authors.forename: H
authors.initials: H
authors.lastname: Rosenberg
mesh_terms: D000818:Animals; D002118:Calcium / Q000493:pharmacokinetics*; D004198:Disease Susceptibility; D006801:Humans; D066298:In Vitro Techniques; D008305:Malignant Hyperthermia / Q000378:metabolism*; D012519:Sarcoplasmic Reticulum / Q000378:metabolism*; D013552:Swine
chemical_list: D002118:Calcium