Assessment of myocardial oxidative stress in patients after myocardial revascularization.
A homogeneous group of six patients, who underwent coronary artery bypass surgery, was studied to determine the presence of oxidative stress caused by oxygen-derived free radicals and its relationship with reperfusion cell damage. Biopsies were performed before ischemia and 10 minutes after reperfusion. The samples were assayed for hydroperoxide-initiated chemiluminescence and histochemical succinic dehydrogenase activity; the specimens were also studied by electron microscopy. The preischemic biopsy specimens showed chemiluminescence of 40 +/- 2 (cpm/mg protein) x 10(3), normal succinic dehydrogenase activity (grade 4), and generally preserved ultrastructure (necrotic/normal cells 5/100). However, the reperfusion biopsy specimens showed an increase in chemiluminescence to 91 +/- 19 (cpm/mg protein) x 10(3) (p less than 0.025), a partial loss of enzymatic activity (grade 2.6), and ultrastructural changes characterized by mitochondrial swelling and focal myofibrillar disorganization (necrotic/normal cells: 15/100; p less than 0.001). These observations seem to indicate the presence of oxidative stress during reoxygenation, a situation that may play a major role in the genesis of reperfusion injury. It appears to be the first observation relating free radical-induced oxidative stress to reperfusion injury in humans.
Ferreira
R
R
Section of Pathology, Institute of Cardiology, Buenos Aires, Argentina.
Llesuy
S
S
Milei
J
J
Scordo
D
D
Hourquebie
H
H
Molteni
L
L
de Palma
C
C
Boveris
A
A
D000328:Adult; D003326:Coronary Circulation; D005609:Free Radicals; D006801:Humans; D008163:Luminescent Measurements; D008854:Microscopy, Electron; D008875:Middle Aged; D008929:Mitochondria, Heart / Q000648:ultrastructure; D008933:Mitochondrial Swelling; D009204:Myocardial Revascularization; D009206:Myocardium / Q000378:metabolism* / Q000648:ultrastructure; D010477:Perfusion; D013385:Succinate Dehydrogenase / Q000378:metabolism*
D005609:Free Radicals; D013385:Succinate Dehydrogenase