HEPARIN FORMULAS CONTAINING CHLOROCRESOL INDUCE CONTRACTURES IN MALIGNANT HYPERTHERMIA SUSCEPTIBLE SKELETAL MUSCLE IN VITRO

1999 ◽  
Vol 88 (Supplement) ◽  
pp. 313S
Author(s):  
M. Anetseder ◽  
L. Ritter ◽  
H. Horbaschek ◽  
E. Hartung ◽  
N. Roewer
Keyword(s):  
Skeletal Muscle ◽  
Malignant Hyperthermia ◽  
Malignant Hyperthermia Susceptible

Comparison of the In-Vitro Effects of Dibucaine on Skeletal Muscle Specimens from Malignant Hyperthermia Susceptible and Normal Patients

2002 ◽  
Vol 96 (Sup 2) ◽  
pp. A76
Author(s):  
Mark U. Gerbershagen ◽  
Frank Wappler ◽  
Marko Fiege ◽  
Ralf Weisshorn ◽  
Jochen Schulte am Esch
Keyword(s):  
Skeletal Muscle ◽  
Malignant Hyperthermia ◽  
Malignant Hyperthermia Susceptible ◽  
In Vitro Effects

Effects of the Serotonin2Receptor Agonist DOI on Skeletal Muscle Specimens from Malignant Hyperthermia-susceptible Patients

1996 ◽  
Vol 84 (6) ◽  
pp. 1280-1287 ◽  
Author(s):  
Frank Wappler ◽  
Norbert Roewer ◽  
Andreas Kochling ◽  
Jens Scholz ◽  
Wolfgang Loscher ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Plasma Concentration ◽  
Malignant Hyperthermia ◽  
Receptor Agonist ◽  
Organ Bath ◽  
Muscle Twitch ◽  
Malignant Hyperthermia Susceptible ◽  
Serotonin System ◽  
In Vitro Effects

Background Administration of serotonin2 (5-HT2) receptor agonists in pigs triggers malignant hyperthermia (MH) and psychotic-like behavior. Both can be reduced by 5-HT2 receptor antagonists. Furthermore, an increase in the plasma concentration of 5-HT has been found during onset of halothane-induced MH in pigs. Therefore, in this study, the in vitro effects of the 5-HT2 receptor agonist 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI) were investigated in muscle specimens from MH-susceptible (MHS) and -negative (MHN) patients. Methods After MH classification using the caffeine-halothane contracture test (CHCT), surplus muscle specimens from 23 MHS and 17 MHN patients were used to examine the effects of DOI. In the first study, DOI was added to the bath in a concentration of 0.02 mM. In a second experiment, muscles were preincubated for 60 min with 0.02 mM DOI, and subsequently, halothane was added incrementally to the organ bath (0.11-0.22-0.44 mM) for 15 min according to the CHCT protocol. The in vitro effects of DOI on contracture development and muscle twitch were measured for 120 min in both investigations. Results Muscle specimens form all patients developed contractures after administration of DOI, characterized by a significantly earlier development of contracture in MHS (16.8 +/- 1.7 min) than in MHN (66.3 +/- 5.8 min) muscles (P < 0.05). There was no overlap between the groups in the range of times. The onset of contracture development after DOI was prolonged by halothane in specimens from MHN patients (89.7 +/- 5.6 min) but not MHS patients. Preincubation with DOI increased the halothane-induced contractures in specimens from MHS patients compared to the results of the CHCT. The contracture development in specimens from MHS patients was larger than from MHN patients. At the end of the experiment, contractures had reached a maximum of 12.9 +/- 1.1 mN in specimens from MHS and 5.3 +/- 0.6 mN in MHN patients (P < 0.05). The additional administration of halothane led to significantly increased contractures in specimens from MHS individuals (15.9 +/- 0.9 mN) at 120 min. However, the contracture development decreased significantly to 3.1 +/- 0.4 mN in MHN muscles. Muscle twitch after DOI administration was reduced significantly in specimens from MHS and MHN patients. Conclusions A functional or structural altered serotonin system might be involved in the development of MH in humans.

Altered E-C coupling in triads isolated from malignant hyperthermia-susceptible porcine muscle

1995 ◽  
Vol 268 (6) ◽  
pp. C1381-C1386 ◽  
Author(s):  
R. el-Hayek ◽  
M. Yano ◽  
B. Antoniu ◽  
J. R. Mickelson ◽  
C. F. Louis ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Malignant Hyperthermia ◽  
Dihydropyridine Receptor ◽  
Normal Muscle ◽  
Direct Stimulation ◽  
Release Channel ◽  
Malignant Hyperthermia Susceptible ◽  
T Tubules ◽  
Junctional Foot Protein ◽  
Stimulation Of

Triad vesicles were isolated from normal (N) and homozygous malignant hyperthermia-susceptible (MHS) porcine skeletal muscle, and two types of sarcoplasmic reticulum Ca2+ release were investigated: 1) polylysine-induced Ca2+ release (direct stimulation of the junctional foot protein), and 2) depolarization-induced Ca2+ release (stimulation of the junctional foot protein via the dihydropyridine receptor). At submaximal concentrations of polylysine, the rates of induced Ca2+ release from the MHS triads were greater than from normal triads. The T tubules of polarized triads were depolarized by the K(+)-to-Na+ ionic replacement protocol. Higher grades of T-tubule depolarization resulted in higher rates of Ca2+ release from both MHS and normal triads but, when compared at a given grade of T-tubule depolarization, the release rate was always greater from the MHS than from normal triads. Thus the activity of the SR Ca2+ release channel is always higher in MHS than in normal muscle at a given submaximal dose of release trigger. This difference is observed when the channel is stimulated directly by polylysine or indirectly via a depolarization-induced activation of the T-tubule dihydropyridine receptor.

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