HEART-MUSCLE UBIQUINONE AND PLASMA ANTIOXIDANTS FOLLOWING CARDIAC TRANSPLANTATION

Nine patients who underwent heart transplantation (one female; average age 48 +/- 11, range 19-58 years) were followed in respect to content s of right-sided heart septum, blood and plasma ubiquinone (UQ), plasm a alpha-tocopherol (alphaT), and plasma free cholesterol (FC). In cont rast to healthy persons, substantial inter- and intraindividual variat ions were observed; individually low values were seen with rejection. Heart muscle UQ in well-treated patients averaged 0.33 +/- 0.08, range 0.06-0.58 mug mg-1 (0.38 +/- 0.09 mumol g-1 dry weight) and was not d ifferent from healthy individuals. Plasma UQ, alphaT; and FC averaged 0.63 +/- 0.33 mug ml-1 (P < 0.05 versus sedentary controls), 8.1 +/- 4 .0 mug ml-1 (P < 0.01), and 0.52 +/- 0.23 mg ml-1 (P < 0.05). Correspo nding molar values were 0.73 +/- 0.37 (UQ), 2.0 +/- 1.1 mumol l-1 (alp haT), and 1.42 +/- 0.54 mmol l-1 (FC). Blood and plasma UQ values were identical. A saturationlike relationship was found between heart and blood UQ: blood contents below 0. 7 mug ml-1 (0.8 mumol l-1) correspon ded to markedly lowered heart contents. In four patients in whom blood samples were taken close to a fatal complication it averaged 0.42 mug ml-1 (0.49 mumol l-1, P < 0.01). When low heart muscle and blood ubiq uinone were present, other variables such as left ventricle cardiac ou tput or cycle ergometer performance was markedly impaired. Plasma UQ a nd alphaT covaried with a marker of the and alphaT over FC (N-UQ and N -alphaT) are alternative means for clinical evaluation. Mean N-alphaT was relatively more depleted than N-UQ. On an individual basis this wa s more pronounced for those with low N-UQ than for those with high val ues.