Sep 1, 1996

Evidence for functional relevance of an enhanced expression of the Na(+)-Ca2+ exchanger in failing human myocardium

Circulation
M FleschM Böhm

Abstract

The present study aimed at investigating the expression of the Na(+)-Ca2+ exchanger and its functional role in human failing myocardium. Na(+)-Ca2+ exchanger mRNA and protein levels were examined in nonfailing (NF, n = 8) and failing human myocardium (New York Heart Association functional class IV) with idiopathic dilated cardiomyopathy (DCM, n = 8) or ischemic heart disease (ICM, n = 6). The inotropic effect of the Na+ channel activator BDF 9148 was determined in electrically driven left ventricular papillary muscle strip preparations (1 Hz, 37 degrees C) from nonfailing (n = 8) and failing (n = 8) human hearts. Na(+)-Ca2+ exchanger mRNA levels were significantly increased, by 79% (P < .001) in DCM and by 58% (P < .01) in ICM compared with NF; protein levels increased by 36% (P < .001) and by 20% (P < .05), respectively. BDF 9148 increased the force of contraction concentration dependently, with a similar maximal effect in NYHA class IV and NF, but was more potent in NYHA class IV as demonstrated by a significantly smaller (P < .01) EC50 value (NYHA class IV, 0.18 [0.16 to 0.22] mumol/L; NF, 1.65 [1.3 to 3.0] mumol/L). In NYHA class IV, BDF 9148 (0.1 mumol/L) restored the positive force-frequency relationship and reduced the f...Continue Reading

  • References41
  • Citations90

Citations

Mentioned in this Paper

Cardiomyopathy, Familial Idiopathic
Chronic Heart Failure
Atrial Natriuretic Factor Precursors
Calcium
Protoplasm
Sodium-Calcium Exchanger
Contraction (Finding)
BDF 9148
Myocardium
Myocardial Stunning

Related Feeds

Cardiomyopathy

Cardiomyopathy is a disease of the heart muscle, that can lead to muscular or electrical dysfunction of the heart. It is often an irreversible disease that is associated with a poor prognosis. There are different causes and classifications of cardiomyopathies. Here are the latest discoveries pertaining to this disease.

Cardiology Journals

Discover the latest cardiology research in this collection of the top cardiology journals.