Whole blood vitamin Q (ubiquinone), plasma vitamins Q and E (alpha-(alpha-)tocopherol) and free cholesterol (FC) were studied before (control or base-line value, sample I) and during open chest surgery and extracorporal circulation (samples II-IV) in 10 male IHD patients. Identity existed between control whole blood and plasma ubiquinone. During surgery an increased discrepancy with lower plasma vitamin Q levels were seen. Control plasma vitamins Q, E and FC averaged 0.88 +/- 0.16 (SE), 12.1 +/- 2.2 mg x l(-1) and 0.75 +/- 0.15 g x l(-1). Corresponding molar values were 1.02 +/- 0.17, 28.1 +/- 5.1 micromol x l(-1) and 1.94 +/- 0.74 mmol x l(-1). Vitamin Q and E decreased continuously and averaged 0.64 mg x l(-1) in sample IV (0.74 micromol x l(-1), p < 0.001) and 9.4 mg x l(-1) in sample III (21.8 micromol x l(-1), p < 0.001). Hemolysis in all sample IV vials, ruined all vitamin E determinations. When normalized for FC (NQ and NE), decreases were found to be 17 (IV) and 12% (III), respectively. Large interindividual variations existed. High control NQ and NE values allowed a larger antioxidant vitamin depletion. High NQ seemed also to be a prerequisite for NE depletion. In addition, signs indicated an active liver vitamin Q release for patients rich in control antioxidant values. It was suggested that the antioxidant vitamin depletion did not prevent from radical trauma to membrane structural lipids (especially omega-3 fatty acids or vitamin F1), less membrane fluidity, erythrocyte fragility and hemolysis.