Detail Research Data


Data Doctoral/PhD
Research Title The Effect of Magnesium on Halothane-Induced Intracellular Calcium Concentration Changes in Cardiomyocytes
Kaji Etik Pass Number
Kaji Etik Pass Date 00 00 0000
Focus Others (-)
Principal Investigator Ratna Farida Soenarto
Departement Anesthesiology
Category Biomedic
Research Date 00 00 0000
Research Object Others
Fund Source
Level Penelitian Doctoral/PhD
Abstract

Background: Halothane, a potent inhalational anesthetic has been known to cause arrhythmia. Studies on skeletal muscle cells of animals with malignant hyperthermia (MH) revealed that halothane activates Ryanodine Receptor (RyR), causing Ca2+ release from sarcoplasmic reticulum (SR) to cytosol and triggers muscle hypercontracture. It is assumed that halothane has the similar effect on cardiac myocytes. Eventhough Mg2+ had been used as an antiarrhythmic agent, the effect on reducing halothane-induced high intracellular Ca2+ concentration is not well studied. Mg2+ hypothetically increases Ca2+ reuptake to SR by increasing SERCA activity. Method: This was an experimental in vitro study on cultured cell of rat cardiomyocytes. Cells were loaded with indicator dye Indo-1 and divided into  five groups of cell and one control group which cells were not exposed to halothane. Cells in group 1 were exposed to halothane, then were discontinued from halothane exposure for zero, five, ten, fifteen and twenty minutes.  Cells in group 2 and 3 were given MgSO411 mM and 22 mM after exposure of halothane, in group 4 and 5 were given MgSO411 mM and 22 mM prior to exposure of halothane. Halothane exposure was in concentration of 2 mM/L (equal to 1-3 MAC) for five minutes duration. The change in cytosolic Ca2+ was recognized by laser scanning confocal microscope and measured by pixel analysis for the emission.   Results: Halothane significantly increased cytosolic Ca2+ concentration in rat cardiac myocytes. MgSO4 that was given before halothane exposure did not prevent this phenomenon. MgSO4 administration after exposure did not significantly decrease Ca2+ concentration, but there was a trend of decreasing Ca2+ concentration with higher dose of Mg2+.  With 1-6 mol/mL of MgSO4, the decrease of cytosolic Ca2+ concentration was almost the same with that after tenminutes discontinuation of halothane. Fifteen minutes discontinuation of halothane significantly decreased cytosolic Ca2+ concentration and twenty minutes discontinuation led the Ca2+ concentration back to basal level. Conclusions: Halothane increases cytosolic Ca2+ concentration in rat cardiac myocytes. Mg2+ in the form of MgSO4 does not significantly decrease cytosolic Ca2+ concentration after halothane exposure. Administraion of Mg2+ in the form of MgSO4 prior to halothane exposure does not prevent the raise of cytosolic Ca2+ concentration in rat cardiac myocyte caused by halothane. Discontinuation of halothane in fifteen minutes will significantly reduce cytosolic Ca2+ concentration. Key words: halothane, cytosolic Ca2+, cardiac myocyte, Mg2+