Hypoxia Delays the Intracellular Ca2+ Clearance by Na+ - Ca2+ Exchanger in Human Adult Cardiac Myocytes.
10.3349/ymj.2001.42.3.333
- Author:
Seung Il PARK
1
;
Eun Ju PARK
;
Nak Hyun KIM
;
Wan Ki BAEK
;
Young Tak LEE
;
Cheol Joo LEE
;
Chang Kook SUH
Author Information
1. Department of Physiology and Biophysics, Inha University College of Medicine, Inchon, Korea. cksuh@inha.ac.kr
- Publication Type:Original Article ; Research Support, Non-U.S. Gov't
- Keywords:
Human;
Na+-Ca2+ exchanger;
hypoxia;
adult cardiac myocytes
- MeSH:
Adult;
Anoxia/*metabolism;
Calcium/*metabolism;
Child;
Child, Preschool;
Female;
Human;
Hydrogen-Ion Concentration;
Infant;
Male;
Middle Age;
Sodium-Calcium Exchanger/*physiology
- From:Yonsei Medical Journal
2001;42(3):333-337
- CountryRepublic of Korea
- Language:English
-
Abstract:
Transient myocardial ischemia during cardiac surgery causes a loss of energy sources, contractile depression, and accumulation of metabolites and H+ ion resulting in intracellular acidosis. The reperfusion following ischemic cardioplegia recovers intracellular pH, activates Na+-H+ exchange and Na+-Ca2+ exchange transports and consequently produces Ca2+ overload, which yields cell death. Among the various Ca2+ entry pathways, the Na+-Ca2+ exchanger is known to play one of the major roles during the ischemia/reperfusion of cardioplegia. Consequently, information on the changes in intracellular Ca2+ activities of human cardiac myocytes via the Na+-Ca2+ exchanger is imperative despite previous measurements of Ca2+ current of human single myocytes. In this study, human single myocytes were isolated from the cardiac tissues obtained during open-heart surgery and intracellular Ca2+ activity was measured with cellular imaging techniques employing fluorescent dyes. We report that the Na+-Ca2+ exchanger of adult cardiac myocytes is more susceptible to hypoxic insult than that of young patients.
