Adenosine inhibits lipopolysaccharide-induced cardiac expression of tumor necrosis factor-α

Abstract

Tumor necrosis factor-α (TNF-α) is elevated in the failing heart. Very little is known about regulation of TNF-α in cardiomyocytes. TNF-α expression by macrophages is diminished by adenosine. Therefore, we hypothesized that a similar mechanism might occur in the heart. Neonatal rat myocytes were stimulated with lipopolysaccharide (LPS), and TNF-α was measured by ELISA. In the absence of LPS, myocytes did not release TNF-α in the medium. After exposure to LPS, TNF-α increased to 70.1±3.5 pg/mL at 6 hours. Immunofluorescent staining confirmed that TNF-α was expressed in myocytes. Adenosine decreased TNF-α in a dose-dependent manner (1 to 100 μmol/L, 37% to 65% decrease, P