Allopurinol modulates reactive oxygen species generation and Ca2+ overload in ischemia-reperfused heart and hypoxia-reoxygenated cardiomyocytes.
Myocardial oxidative stress and Ca2+ overload induced by ischemia-reperfusion may be involved in the development and progression of myocardial dysfunction in heart failure. Xanthine oxidase, which is capable of producing reactive oxygen species, is considered as a culprit regarding ischemia-reperfusion injury of cardiomyocytes. Even though inhibition of xanthine oxidase by allopurinol in failing hearts improves cardiac performance, the regulatory mechanisms are not known in detail. We therefore hypothesized that allopurinol may prevent the xanthine oxidase-induced reactive oxygen species production and Ca2+ overload, leading to decreased calcium-responsive signaling in myocardial dysfunction. Allopurinol reversed the increased xanthine oxidase activity in ischemia-reperfusion injury of neonatal rat hearts. Hypoxia-reoxygenation injury, which simulates ischemia-reperfusion injury, of neonatal rat cardiomyocytes resulted in activation of xanthine oxidase relative to that of the control, indicating that intracellular xanthine oxidase exists in neonatal rat cardiomyocytes and that hypoxia-reoxygenation induces xanthine oxidase activity. Allopurinol (10 microM) treatment suppressed xanthine oxidase activity induced by hypoxia-reoxygenation injury and the production of reactive oxygen species. Allopurinol also decreased the concentration of intracellular Ca2+ increased by enhanced xanthine oxidase activity. Enhanced xanthine oxidase activity resulted in decreased expression of protein kinase C and sarcoendoplasmic reticulum calcium ATPase and increased the phosphorylation of extracellular signal-regulated protein kinase and p38 kinase. Xanthine oxidase activity was increased in both ischemia-reperfusion-injured rat hearts and hypoxia-reoxygenation-injured cardiomyocytes, leading to reactive oxygen species production and intracellular Ca2+ overload through mechanisms involving p38 kinase and extracellular signal-regulated protein kinase (ERK) via sarcoendoplasmic reticulum calcium ATPase (SERCA) and protein kinase C (PKC). Xanthine oxidase inhibition with allopurinol modulates reactive oxygen species production and intracellular Ca2+ overload in hypoxia-reoxygenation-injured neonatal rat cardiomyocytes.
Kang
Seok-Min
SM
Cardiovascular Research Institute, Cardiology Division, Department of Internal Medicine, Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, Seoul, 120-752, South Korea.
Lim
Soyeon
S
Song
Heesang
H
Chang
Woochul
W
Lee
Sunju
S
Bae
Sang-mee
SM
Chung
Ji Hyung
JH
Lee
Hakbae
H
Kim
Ho-Gyoung
HG
Yoon
Deok-Hyo
DH
Kim
Tae Woong
TW
Jang
Yangsoo
Y
Sung
Jae-Mo
JM
Chung
Nam-Sik
NS
Hwang
Ki-Chul
KC
D000493:Allopurinol / Q000494:pharmacology*; D000818:Animals; D000831:Animals, Newborn; D002118:Calcium / Q000378:metabolism*; D000252:Calcium-Transporting ATPases / Q000378:metabolism; D015687:Cell Hypoxia; D002478:Cells, Cultured; D005434:Flow Cytometry; D016166:Free Radical Scavengers / Q000494:pharmacology; D008297:Male; D018613:Microscopy, Confocal; D015428:Myocardial Reperfusion Injury / Q000503:physiopathology; D009206:Myocardium / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology; D032383:Myocytes, Cardiac / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D010100:Oxygen / Q000494:pharmacology; D011493:Protein Kinase C / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species / Q000378:metabolism*; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases; D015398:Signal Transduction / Q000187:drug effects; D014969:Xanthine Oxidase / Q000037:antagonists & inhibitors / Q000378:metabolism
D016166:Free Radical Scavengers; D017382:Reactive Oxygen Species; D000493:Allopurinol; D014969:Xanthine Oxidase; D011493:Protein Kinase C; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases; D000252:Calcium-Transporting ATPases; D010100:Oxygen; D002118:Calcium