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)

The effects of caffeine, halothane, succinylcholine, phenylephrine and isoproterenol on force of contraction were studied in electrically driven (0.2 Hz) trabeculae isolated from the right ventricles of the hearts of malignant hyperthermia susceptible (MHS) and healthy control (nMHS) swine. Caffeine (0.1-10 mmol/l) had positive inotropic effects, amounting to 275 +/- 35% of control in nMHS and 268 +/- 34% in MHS (n = 16). Halothane (0.25-4 vol%) decreased the force of contraction maximally to 52 +/- 4% in nMHS and 51 +/- 5% of control in MHS (n = 16). Propranolol did not change these effects. Succinylcholine (0.1-10000 mumol/l) had a small positive inotropic effect in both groups, which was blocked by propranolol. Phenylephrine (0.1-300 mumol/l) increased the force of contraction maximally to 188 +/- 24% of control in nMHS and to 193 +/- 23% in MHS (n = 16). The inotropic effect was blocked by prazosin but not by succinylcholine (1 mmol/l). Isoproterenol (0.01-10 mumol/l) had a positive inotropic effect of maximally 275 +/- 21% of control in nMHS and 396 +/- 31% in MHS (n = 17) (P less than 0.05). Succinylcholine potentiated this effect, and propranolol shifted the concentration-response curves to the right. We conclude that caffeine, halothane, succinylcholine and phenylephrine have similar inotropic effects in the hearts of nMHS and MHS, whereas isoproterenol has a significantly greater effect in MHS than in nMHS.
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PMID:Effects of caffeine, halothane, succinylcholine, phenylephrine and isoproterenol on myocardial force of contraction of malignant hyperthermia susceptible swine. 185 93

In vitro contracture tests for susceptibility to malignant hyperthermia (MH) were performed with halothane and caffeine in 27 patients according to the protocol of the European MH Group. Additional halothane and caffeine tests were performed in the presence of propranolol 80 micrograms/l. Contractures after exposure to halothane were seen only in MH-susceptible (MHS) patients (n = 12), and were not affected by propranolol. In contrast, propranolol shifted the caffeine dose-response curve to the right and significantly increased the caffeine threshold in the MHS group. Propranolol did not influence the caffeine results in the normal response group group (n = 12). It is concluded that beta-blockers should be discontinued before investigation for MH susceptibility.
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PMID:Influence of propranolol on the in vitro response to caffeine and halothane in malignant hyperthermia-susceptible muscle. 280 Sep 78