Yonsei Med J.  2010 Mar;51(2):187-196. 10.3349/ymj.2010.51.2.187.

Cardioprotection Via Modulation of Calcium Homeostasis by Thiopental in Hypoxia-Reoxygenated Neonatal Rat Cardiomyocytes

• Kim HS
• Hwang KC
• Park WK

• KMID: 1126016
• DOI: http://doi.org/10.3349/ymj.2010.51.2.187

Abstract

PURPOSE
Ca2+ homeostasis plays an important role in myocardial cell injury induced by hypoxia-reoxygenation, and prevention of intracellular Ca2+ overload is key to cardioprotection. Even though thiopental is a frequently used anesthetic agent, little is known about its cardioprotective effects, particulary in association with Ca2+ homeostasis. We investigated whether thiopental protects cardiomyocytes against hypoxia-reoxygenation injury by regulating Ca2+ homeostasis.
MATERIALS AND METHODS
Neonatal rat cardiomyocytes were isolated. Cardiomyocytes were exposed to different concentrations of thiopental and immediately replaced in the hypoxic chamber to maintain hypoxia. After 1 hour of exposure, a culture dish was transferred to the CO2 incubator and cells were incubated at 37degrees C for 5 hours. At the end of the experiments, the authors assessed cell protection using immunoblot analysis and caspase activity. The mRNA of genes involved in Ca2+ homeostasis, mitochondrial membrane potential, and cellular Ca2+ levels were examined.
RESULTS
In thiopental-treated cardiomyocytes, there was a decrease in expression of the proapoptotic protein Bax, caspase-3 activation, and intracellular Ca2+ content. In addition, both enhancement of anti-apoptotic protein Bcl-2 and activation of Erk concerned with survival were shown. Furthermore, thiopental attenuated alterations of genes involving Ca2+ regulation and significantly modulated abnormal changes of NCX and SERCA2a genes in hypoxia-reoxygenated neonatal cardiomyocytes. Thiopental suppressed disruption of mitochondrial membrane potential (Delta Psi m) induced by hypoxia-reoxygenation.
CONCLUSION
Thiopental is likely to modulate expression of genes that regulate Ca2+ homeostasis, which reduces apoptotic cell death and results in cardioprotection.

Keyword

Thiopental; Ca2+ homeostasis; hypoxia-reoxygenation; cardiomyocytes

MeSH Terms

Animals
Apoptosis
Calcium/*metabolism
Cell Hypoxia/*physiology
Cell Survival/drug effects
Cells, Cultured
GABA Modulators/*pharmacology
Homeostasis/drug effects
Immunoblotting
In Situ Nick-End Labeling
Membrane Potential, Mitochondrial/drug effects
Microscopy, Confocal
Myocytes, Cardiac/*drug effects/*metabolism
Rats
Rats, Sprague-Dawley
Reverse Transcriptase Polymerase Chain Reaction
Thiopental/*pharmacology