3,4-Methylenedioxymethamphetamine induces a hyperthermic and hypermetabolic crisis in pigs with and without a genetic disposition for malignant hyperthermia.

Background: Clinical symptoms of acute 3,4-methylenedioxymethamphetamine (MDMA) intoxication and malignant hyperthermia have many similarities. At present, however, there is contradictory evidence concerning the malignant hyperthermia trigger potency of MDMA.

Objective: This study was designed to investigate whether MDMA has malignant hyperthermia trigger potential and leads to malignant hyperthermia in pigs with or without a genetic predisposition to the condition.

3,4-Methylenedioxymethamphetamine (Ecstasy) increases the sensitivity of the contractile apparatus to calcium ions in both malignant hyperthermia-susceptible and normal skeletal muscle fibres.

Context And Objectives: The present study was designed to investigate whether 3,4-methylenedioxymethamphetamine (MDMA, 'Ecstasy') increases the sensitivity of the contractile apparatus to calcium in muscle fibres from malignant hyperthermia-susceptible and malignant hyperthermia-negative pigs, whether it causes calcium ion release from the sarcoplasmic reticulum and whether it inhibits calcium reuptake into the sarcoplasmic reticulum.

Design: Experimental study, using a model of porcine saponin-skinned fibres.

Results: Administration of MDMA in concentrations of 1, 2 and 4 mmol l(-1)l did not result in relevant force transients in skinned muscle fibres of malignant hyperthermia-susceptible or malignant hyperthermia-negative pigs.

Comparison of the therapeutic effectiveness of a dantrolene sodium solution and a novel nanocrystalline suspension of dantrolene sodium in malignant hyperthermia normal and susceptible pigs.

Background And Objective: Stopping trigger agents and prompt administration of dantrolene are the cornerstones of treatment of malignant hyperthermia. However, significant time is lost in treatment of the condition because of the cumbersome preparation and administration of the commercially available dantrolene sodium for injection. A potential improvement has become available in the form of a novel nanocrystalline dantrolene sodium suspension (DSS), which is 150 times more concentrated (50 mg ml(-1)) than the standard dantrolene sodium solution (0.