[Adenosine protects cardiomyocytes from hypoxia/reoxygenation injury].
The aim of this study was to investigate the protective effect of adenosine (ADO) on cardiomyocytes following hypoxia/reoxygenation (H/R) and its molecular mechanism. Primary cultured cardiomyocytes of neonatal rats were divided into two groups, namely H/R (control) and ADO (1.0 micromol/L) groups. The morphologic changes in cardiomyocytes were observed under an inverted phase-contrast microscope. The following parameters of the two groups were determined: lactate dehydrogenase (LDH) activity, intracellular calcium concentration and malondialdehyde (MDA) content. Tumor necrotic factor (TNF-alpha) assay was performed using an ELISA kit and NF-kappaB in the nucleus was analyzed by electrophoretic mobility shift assay (EMSA). The results are as follows: (1) after H/R injury, cardiomyocytes contracted, tending to get round in shape and its pseudopods decreased, while marked morphological changes were not observed in ADO group; (2) LDH leakage maintained at a lower level in ADO group than that in the control group during H/R (both P<0.01); (3) ADO significantly reduced the concentration of calcium in cells and prevented calcium overload during H/R (both P<0.01); (4) ADO markedly reduced the content of MDA during H/R (both P<0.01); (5) ADO inhibited the production of TNF-alpha during H/R (both P<0.01); and (6) ADO down-regulated NF-kappaB binding activity of cardiomyocytes during H/R (both P<0.01) The results suggest that (1) exogenous ADO attenuates H/R injury of cultured cardiomyocytes; (2) exogenous ADO inhibits the production of TNF-alpha after H/R injury; (3) exogenous ADO prevents the activation of NF-kappaB, which may be the molecular mechanism of down-regulation of TNF-alpha expression.
Wang
Xing-Xiang
XX
Department of Cardiology, Union Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022. wangxx19730312@yahoo.com.cn
Zhou
Li-Long
LL
Ding
Jia-Wang
JW
Feng
Yi-Bai
YB
Cheng
Long-Xian
LX
D000241:Adenosine / Q000494:pharmacology*; D000818:Animals; D000831:Animals, Newborn; D015687:Cell Hypoxia; D002478:Cells, Cultured; D015536:Down-Regulation / Q000187:drug effects; D032383:Myocytes, Cardiac / Q000166:cytology* / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D015427:Reperfusion Injury / Q000378:metabolism / Q000503:physiopathology / Q000517:prevention & control*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
D016328:NF-kappa B; D014409:Tumor Necrosis Factor-alpha; D000241:Adenosine