EFFECTS OF VOLATILE ANESTHETICS ON SODIUM/ HYDROGEN EXCHANGER ACTIVITY IN ISCHEMIC-REPERFUSION

1999 Fiscal Year Final Research Report Summary

• Project/Area Number: 10671409
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Anesthesiology/Resuscitation studies
• Research Institution: YAMANASHI MEDICAL UNIVERSITY
• Principal Investigator: NONAKA Akihiko Yamanashi Medical University, Dept. of Anesthesiology, Assistant Professor, 医学部, 講師 (90228338)
• Co-Investigator(Kenkyū-buntansha): KUMAZAWA Teruo Yamanashi Medical University, Dept. of Anesthesiology, Professor, 医学部, 教授 (10092404)
• Project Period (FY): 1998 – 1999
• Keywords: MYOCYTES / CALCIUM HYDROGEN EXCHANGER / VOLATILE ANESTHETICS / H+交換系

Research Abstract

We studied the effects of volatile anesthetics on sodium/hydrogen exchanger activity under ischemic-reperfusion injury. In this study, we examined Na+/H+ exchange activity, Ca2+ transients, and contractility in isolated rabbit ventricular myocytes. Intracellular H.+ (pHi) and Na+ concentration ([Na+]i) were measured with the fluorescent pH indicators BCEFC and SBFI, respectively, and contractility was assessed from changes in cell shortening during field stimulation. Experiments were performed at extra cellular pH 7. 4 in the presence of HEPES buffer.
Our findings demonstrate that 1) halothane significantly decreased contractility, 2) ischemic-reperfusion caused increases in [Na+]i and decreases in pHi, 3) halothane attenuate the magnitude in increases in [Ca2+]i and decreases in pHi during reperfusion, 4) halothane attenuate the magnitude in decreases in pHi during ischemic period. It is suggested that a reduction of excessive intracellular hydrogen after reperfusion mused by halothane may be beneficial on myocardial function following repeffusion in the intact rabbit myocardium.