[Mechanism of selenium defending against free radical damages during myocardial ischemia/reperfusion in human].
OBJECTIVE
To investigate the modulate mechanism of selenium (Se) on glutathione peroxidase expression in the myocardium by defending against free radical superoxidizing during myocardial ischemia/reperfusion (I/R) period.


METHODS
46 patients with ASD or VSD were separated into control (23 patients) and Se (23 patients) groups. Patients in the Se group received 400 micrograms Se supplementation each day for 7 days before heart surgery. Biochemical techniques, atomic absorption, RT-PCR, cDNA sequence testing were taken to evaluate and compare the changes in myocadial MDA level, GPX activity, GPX mRNA expression, GPX cDNA nucleotide sequence, and Se, Ca and Mg concentrations during I/R.


RESULTS
In Se group, Se supplementation by oral administration neither changed plasma Se content nor blood cells. At 30 minute of myocardial reperfusion, in Se group, Se content in the myocardium did significantly increase but decreased in RBCs, and the elementary rate of GPX activity was lower than that in control. Se group had higher myocardial GPX mRNA expression with a normal nucleotida sequence pre- and post-reperfusion.


CONCLUSIONS
Se supplement, which promotes the myocardial Se content and mainly improves GPX mRNA expression during I/R, can defend against free radical superoxidizing damages to the myocardium.
Huang
Y
Y
Beijing Institute of Heart Lung & Blood Vessel Disease, Beijing 100029.
Liu
Y
Y
Zhang
Z
Z
D000293:Adolescent; D000328:Adult; D002315:Cardiopulmonary Bypass; D002648:Child; D005260:Female; D005979:Glutathione Peroxidase / Q000096:biosynthesis* / Q000235:genetics; D006344:Heart Septal Defects, Atrial / Q000188:drug therapy / Q000378:metabolism / Q000601:surgery; D006345:Heart Septal Defects, Ventricular / Q000188:drug therapy* / Q000378:metabolism / Q000601:surgery; D006801:Humans; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D015428:Myocardial Reperfusion Injury / Q000378:metabolism*; D009206:Myocardium / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D012643:Selenium / Q000378:metabolism / Q000627:therapeutic use*
D012333:RNA, Messenger; D008315:Malondialdehyde; D005979:Glutathione Peroxidase; D012643:Selenium