Treatment of Normal Skeletal Muscle with FK506 or Rapamycin Results in Halothane-induced Muscle Contracture
| Autor: | Richard Brooksbank, Hyam Isaacs, Margaret E. Badenhorts, Nerina Savage |
|---|---|
| Rok vydání: | 1998 |
| Předmět: |
Adult
medicine.medical_specialty Adolescent Polyenes In Vitro Techniques Tacrolimus Tacrolimus Binding Proteins Internal medicine medicine Humans Child Muscle Skeletal Heat-Shock Proteins Muscle contracture Sirolimus Ryanodine receptor business.industry Malignant hyperthermia Skeletal muscle Ryanodine Receptor Calcium Release Channel Middle Aged medicine.disease DNA-Binding Proteins Anesthesiology and Pain Medicine Endocrinology medicine.anatomical_structure Mechanism of action Child Preschool Anesthetics Inhalation Calcium Halothane medicine.symptom Contracture Carrier Proteins Malignant Hyperthermia business Immunosuppressive Agents Muscle Contraction medicine.drug Muscle contraction |
| Zdroj: | Anesthesiology. 89:693-698 |
| ISSN: | 0003-3022 |
| Popis: | Background FKBP12 is a protein that is closely associated with the ryanodine receptor type 1 of skeletal muscle and modulates Ca2+ release by the channel. The immunosuppressants FK506 and rapamycin both bind to FKBP12 and in turn dissociate the protein from the ryanodine receptor. By treating healthy human skeletal muscle strips with FK506 or rapamycin and then subjecting the strips to the caffeine-halothane contracture test, this study determined that FK506 and rapamycin alter the sensitivity of the muscle strip to halothane, caffeine, or both. Methods Skeletal muscle strips from 10 healthy persons were incubated in Krebs medium equilibrated with a 95% oxygen and 5% carbon dioxide mixture, which contained either 12 microM FK506 (n = 8) or 12 microM rapamycin (n = 6), for 15 min at 37 degrees C. The strips were subjected to the caffeine-halothane contracture test for malignant hyperthermia according to the European Malignant Hyperthermia Group protocol. Results Treatment of normal skeletal muscle strips with FK506 and rapamycin resulted in halothane-induced contractures of 0.44+/-0.16 g and 0.6+/-0.49 g, respectively, at 2% halothane. Conclusions The results obtained show that pre-exposure of healthy skeletal muscle strips to either FK506 or rapamycin is sufficient to give rise to halothane-induced contractures. This is most likely caused by destabilization of Ca2+ release by the ryanodine receptor as a result of the dissociation of FKBP12. This finding suggests that a mutation in FKBP12 or changes in its capacity to bind to the ryanodine receptor could alter the halothane sensitivity of the skeletal muscle ryanodine receptor and thereby predispose the person to malignant hyperthermia. |
| Databáze: | OpenAIRE |
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