PMID- 12944436
OWN - NLM
STAT- MEDLINE
DCOM- 20040401
LR  - 20191107
IS  - 0832-610X (Print)
IS  - 0832-610X (Linking)
VI  - 50
IP  - 7
DP  - 2003 Aug-Sep
TI  - The ryanodine contracture test may help diagnose susceptibility to malignant 
      hyperthermia.
PG  - 643-8
AB  - PURPOSE: The ryanodine contracture test (RCT) using the plant alkaloid ryanodine 
      as the triggering agent has been proposed to reduce equivocal results of the in 
      vitro caffeine-halothane-contracture test (IVCT), which is the accepted and 
      standardized procedure to diagnose malignant hyperthermia (MH). However, the 
      response of skeletal muscle of non-MH affected patients (controls) to ryanodine 
      has not yet been characterized. METHODS: Skeletal muscle biopsies were studied in 
      33 controls and in six patients with a history of fulminant MH. Following the 
      IVCT, the RCT was performed in all specimens using ryanodine 1 micro M. Onset 
      time of contracture and time to reach a contracture level of 10 mN above lowest 
      resting tension and above predrug tension were calculated. RESULTS: With the 
      standard IVCT, all controls were labelled MH non-susceptible; all clinically 
      diagnosed MH patients were labelled MH susceptible. With ryanodine, control 
      muscle differed from MH susceptible muscle regarding onset time of contracture 
      (26 vs 3.8 min, P < 0.05) and time to reach a contracture of 10 mN (49 vs 12.5 
      min, P < 0.05; all median). Tissue viability and patient's age significantly 
      influenced contracture times. CONCLUSIONS: Despite the highly specific binding of 
      ryanodine at the myocytic sarcoplasmic reticulum, the wide range of contracture 
      times of the controls points toward heterogeneity of ryanodine receptors within 
      physiologic limits. This may also be caused in part by tissue viability and the 
      patients' age. The ryanodine contracture test performed in addition to the IVCT 
      may add clarity into diagnosing a patient as MH-susceptible or not.
FAU - Reuter, Daniel A
AU  - Reuter DA
AD  - Department of Anesthesiology, University of Munich, Germany. 
      Daniel.Reuter@ana.med.uni-muenchen.de
FAU - Anetseder, Martin
AU  - Anetseder M
FAU - Muller, Rainer
AU  - Muller R
FAU - Roewer, Norbert
AU  - Roewer N
FAU - Hartung, Edmund J
AU  - Hartung EJ
LA  - eng
PT  - Journal Article
PL  - United States
TA  - Can J Anaesth
JT  - Canadian journal of anaesthesia = Journal canadien d'anesthesie
JID - 8701709
RN  - 0 (Anesthetics, Inhalation)
RN  - 15662-33-6 (Ryanodine)
RN  - UQT9G45D1P (Halothane)
SB  - IM
MH  - Adult
MH  - Aged
MH  - Anesthetics, Inhalation/pharmacology/*toxicity
MH  - Female
MH  - Halothane/pharmacology/*toxicity
MH  - Humans
MH  - In Vitro Techniques
MH  - Male
MH  - Malignant Hyperthermia/diagnosis/*etiology
MH  - Middle Aged
MH  - Muscle Contraction/*drug effects
MH  - Muscle, Skeletal/*drug effects/pathology
MH  - Reproducibility of Results
MH  - Ryanodine/pharmacology/*toxicity
EDAT- 2003/08/29 05:00
MHDA- 2004/04/02 05:00
CRDT- 2003/08/29 05:00
PHST- 2003/08/29 05:00 [pubmed]
PHST- 2004/04/02 05:00 [medline]
PHST- 2003/08/29 05:00 [entrez]
AID - 10.1007/BF03018704 [doi]
PST - ppublish
SO  - Can J Anaesth. 2003 Aug-Sep;50(7):643-8. doi: 10.1007/BF03018704.