Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0024591 (malignant hyperthermia)
 2,353 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. Native 6% Laemmli gels were used to resolve 7 protein kinase activity bands in control and malignant hyperthermia (MH)-susceptible porcine and human skeletal muscle extracts. 2. MH-susceptible samples were consistently more active than the controls. 3. Following halothane treatment, a 43 kDa component displayed increased phosphorylation by a calcium-calmodulin dependent kinase in MH-susceptible vs control human samples. 4. Increased phosphorylation of additional endogenous protein components of molecular mass 116 and 60 kDa was observed.
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PMID:Kinase activity and protein phosphorylation in control and malignant hyperthermic skeletal muscle. 201 52

In vitro contracture tests used currently for malignant hyperthermia (MH) do not possess absolute specificity. This is potentially a great problem in the study of the genetic approach which offers the best prospect for the development of a non-invasive diagnostic test for the condition. The calcium release channel of the sarcoplasmic reticulum has been proposed as the site of the MH defect. Ryanodine, which binds avidly to this channel, was shown to differentiate between muscle of MH susceptible and normal patients in terms of in vitro contracture response. This ryanodine contracture response is proposed as a potentially specific in vitro diagnostic test for MH.
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PMID:Ryanodine contracture: a potentially specific in vitro diagnostic test for malignant hyperthermia. 203 23

Alpha-adrenoceptor stimulation may induce malignant hyperthermia (MH) in vivo. Consequently, we have investigated the effects of the alpha-adrenoceptor agonist phenylephrine and, for comparison, the effects of the beta-adrenoceptor agonist isoproterenol on inositol-lipid metabolism of malignant hyperthermia susceptible (MHS) and healthy control (MHN) swine. The experiments were performed on electrically stimulated (frequency 0.2 Hz) trabeculae isolated from the right ventricles of the hearts of MHS and MHN animals. After labelling with [3H]inositol for 6 h, different inositol phosphates were measured by high pressure liquid chromatography, including inositol 1-phosphate, inositol 1,4-bisphosphate, inositol 1,3,4-trisphosphate, inositol 1,4,5-trisphosphate (1,4,5-IP3) and inositol 1,3,4,5-tetrakisphosphate. After stimulation with isoproterenol, the inositol phosphate content did not increase or vary between muscle from MHS and MHN animals. In contrast, all inositol phosphates increased after stimulation with phenylephrine in both muscle types, the effects being greater in MHS than in MHN, especially as regards 1,4,5-IP3 content. As 1,4,5-IP3, a presumed second messenger, has been shown to mobilize intracellular calcium, it is concluded that an enhanced alpha-adrenergic response is involved in the development of MH.
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PMID:Possible involvement of inositol-lipid metabolism in malignant hyperthermia. 206 84

The concentration of ionized cytosolic calcium [( Ca2+]i) was determined in peripheral blood mononuclear cells from normal and malignant hyperthermia (MH)-susceptible humans and pigs, using the fluorescent Ca2+ indicator indo-1. [Ca2+]i was slightly but significantly elevated in cells from MH human cells relative to normal cells (198 +/- 18 nM, n = 15, and 146 +/- 14 nM, n = 11, respectively, P less than 0.05). Anesthetic concentrations of halothane in the cell suspension resulted in a rapid increase in [Ca2+]i in cells from both normal and MH humans or pigs. The increases (delta) were more pronounced in cells from MH subjects than from normal individuals (delta at 5.7 mM halothane: 245 +/- 53 vs. 57 +/- 11 nM, respectively) and from MH than from normal pigs (delta of 241 +/- 63 vs. 53 +/- 27 nM, respectively). Removal of extracellular Ca2+ obliterated the delta[Ca2+]i caused by halothane in cells from normal humans or pigs but only decreased by about half the delta[Ca2+]i in cells from MH humans or pigs. In 1,2-bis-(aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA)-loaded cells, in the absence of extracellular Ca2+, halothane failed to increase [Ca2+]i. This suggests that buffering Cai2+ with BAPTA precludes detection of release of Ca2+ from intracellular stores, explaining the previous observations made with quin2, a highly chelating Ca2+ indicator. It is concluded that clinical concentrations of halothane allow influx of Ca2+ in cells from both normal and MH-susceptible individuals but release Ca2+ from intracellular stores selectively in cells from the latter group.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Halothane-dependent release of intracellular Ca2+ in blood cells in malignant hyperthermia. 210 50

Based on studies in swine, the malignant hyperthermia syndrome has been postulated to result from an enhanced sensitivity (low threshold) of the Ca2(+)-induced Ca2(+)-release process. However, fatty acid production is elevated in homogenates of skeletal muscle from pigs and humans susceptible to malignant hyperthermia. In the present study, we demonstrate that the threshold of Ca2(+)-induced Ca2+ release is normal in susceptible humans and in susceptible swine depleted of triglycerides. Exogenously added unsaturated fatty acids decreased the threshold of Ca2(+)-induced Ca2+ release to a much greater extent in porcine and equine muscle than in human muscle. When triglyceride and free fatty acid values were reduced to about 40 and 60%, respectively, of control values, malignant hyperthermia-susceptible swine did not exhibit muscle rigidity when challenged in vivo with halothane and succinylcholine and the threshold of the Ca2(+)-induced Ca2(+)-release process in heavy sarcoplasmic reticulum fractions was normal. Despite the reduced triglyceride and fatty acid levels, these swine had a positive in vitro contracture test for malignant hyperthermia. A low Ca2(+)-induced Ca2(+)-release threshold is not essential for malignant hyperthermia susceptibility, but appears to be the result of excessive free fatty acids produced during organelle isolation.
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PMID:Fatty acids modulate calcium-induced calcium release from skeletal muscle heavy sarcoplasmic reticulum fractions: implications for malignant hyperthermia. 212 24

1. Ca2+ uptake, Ca2(+)-dependent ATPase activity and halothane-induced Ca2+ release from the heavy sarcoplasmic reticulum fraction of muscle from malignant hyperthermia susceptible individuals are similar to those of normal human muscle. 2. Ca2(+)-induced Ca2+ release from the diseased muscle was increased by 13%.
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PMID:Uptake and release of calcium ions by heavy sarcoplasmic reticulum fraction of normal and malignant hyperthermia-susceptible human skeletal muscle. 214 Jan 3

We investigated the effect of halothane on lipid and protein components of sarcoplasmic reticulum membranes isolated from pig trapezius muscle. We studied the relationships between the (Ca2(+)-Mg2+)-ATPase activity and the interaction of the anesthetic with lipid and protein moieties by means of EPR and fluorescence spectroscopic techniques. Our results clearly show that below 5 mumol per mg protein, halothane interacts mainly with the lipid components of the membrane. This interaction is shown to be localized in the central core of the phospholipid bilayer and to induce an increase of the membrane calcium permeability. The interaction with protein components only occurs at higher halothane concentrations and affects its conformational and functional states. These results are discussed with respect to new insights into diethylether-SR membrane interaction and to malignant hyperthermia syndrome in the pig.
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PMID:Halothane-induced functional and structural modifications in sarcoplasmic reticulum membranes from pig skeletal muscle. 214 22

Sarcoplasmic reticulum isolated from malignant hyperthermia-susceptible (MHS) muscle exhibits abnormalities in the regulation of calcium release. To identify the molecular basis of this abnormality, the Ca2+ release channel from both normal and MHS sarcoplasmic reticulum was examined using proteolytic digestion followed by immunoblot staining with a polyclonal antibody against the rabbit Ca2+ release channel protein. Under appropriate conditions, trypsin digestion of isolated sarcoplasmic reticulum vesicles from the two types of pigs revealed a distinct difference in the immunostaining pattern of the Ca2+ release channel-derived peptides. An approximate 86-kDa peptide was the predominant fragment in normal sarcoplasmic reticulum while an approximate 99-kDa peptide fragment was the major peptide detected in MHS sarcoplasmic reticulum. Digestion of sarcoplasmic reticulum vesicles isolated from four normal and four MHS pigs showed that the differences were highly reproducible. Trypsin digestion of sarcoplasmic reticulum isolated from heterozygous pigs, which contain one normal and one MHS allele, showed an antibody staining pattern that was intermediate between MHS and normal sarcoplasmic reticulum. These results can be explained by a primary amino acid sequence difference between the normal and MHS Ca2+ release channels and support the hypothesis that a mutation in the gene coding for the sarcoplasmic reticulum Ca2+ release channel is responsible for malignant hyperthermia.
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PMID:Distinct immunopeptide maps of the sarcoplasmic reticulum Ca2+ release channel in malignant hyperthermia. 215 46

The muscle disease malignant hyperthermia is a disorder of intracellular free Ca2+ regulation in both humans and pigs. Current evidence indicates that the Ca2+ channel of the sarcoplasmic reticulum of MH muscle is abnormally sensitive to Ca2+ and to halothane. Mitochondria, the sarcolemma and the transverse tubule appear not to be involved in primary pathogenesis of MH. Molecular genetic studies indicate that the MH gene is on human chromosome 19 and that the likely candidate gene is that coding for the Ca2+ channel.
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PMID:Current views of the molecular basis of the malignant hyperthermia syndrome. 216 42

Several studies point to the possibility that malignant hyperthermia (MH) in pigs is caused by a defect in the calcium release channel (CRC) of skeletal muscle sarcoplasmic reticulum. The locus for MH is closely linked to the glucosephosphate isomerase (GPI) locus, near the centromere of chromosome 6. We demonstrate synteny of the genes for CRC and GPI using somatic cell hybrid lines, and assign the CRC gene to chromosome 6p11----q21 by in situ hybridization.
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PMID:Assignment of the porcine calcium release channel gene, a candidate for the malignant hyperthermia locus, to the 6p11----q21 segment of chromosome 6. 217 5


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