Heart muscle ubiquinone and plasma antioxidants following cardiac transplantation

Summary

Nine patients who underwent heart transplantation (one female; average age 48 ± 11, range 19–58 years) were followed in respect to contents of right-sided heart septum, blood and plasma ubiquinone (UQ), plasma α-tocopherol (αT), and plasma free cholesterol (FC). In contrast to healthy persons, substantial inter- and intraindividual variations 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 μg mg⁻¹ (0.38 ± 0.09 μmol g⁻¹ dry weight) and was not different from healthy individuals. Plasma UQ, αT; and FC averaged 0.63 ± 0.33 μg ml⁻¹ (P < 0.05 versus sedentary controls), 8.1 ± 4.0 μg ml⁻¹ (P < 0.01), and 0.52 ± 0.23 mg ml⁻¹ (P < 0.05). Corresponding molar values were 0.73 ± 0.37 (UQ), 2.0 ± 1.1 μmol l⁻¹ (αT), and 1.42 ± 0.54 mmol 1⁻¹ (FC). Blood and plasma UQ values were identical. A saturationlike relationship was found between heart and blood UQ: blood contents below 0.7 μg ml⁻¹ (0.8 μmol l⁻¹) corresponded to markedly lowered heart contents. In four patients in whom blood samples were taken close to a fatal complication it averaged 0.42 μg ml⁻¹ (0.49 μmol l^−t, P < 0.01). When low heart muscle and blood ubiquinone were present, other variables such as left ventricle cardiac output or cycle ergometer performance was markedly impaired. Plasma UQ and off covaried with a marker of the lipoidal deposit volume, plasma FC. The ratios UQ and αT over FC (N-UQ and N-αT) are alternative means for clinical evaluation. Mean N-αT was relatively more depleted than N-UQ. On an individual basis this was more pronounced for those with low N-UQ than for those with high values.