Protective role of coenzyme Q10 in two models of rat lung injury

Ischaemia-reperfusion injury is a life-threatening complication of lung transplantation. Attempts to ameliorate this injury have included optimization of donor management and improving techniques of lung preservation. However, few investigators have sought to pretreat potential recipients. Coenzyme Q(10) (CoQ(10)) is a potent antioxidant and cellular energizer that has been shown to protect the heart against injury. However, its protective effect in the lung is unknown. We therefore set out to study the impact of Coenzyme Q(10) pretreatment in a model of mild and severe lung injury.

We evaluated the impact of CoQ(10) in a two-stage laboratory study. In the first stage, in order to measure the magnitude of increase in tissue and plasma CoQ(10) following oral therapy we administered high-dose oral CoQ(10) to rats (n = 6). In the second stage we evaluated the impact of CoQ(10) in the rat lung (n = 10) that was subjected to 230 min of normoxic lung injury or 90 min of warm ischaemia and 120 min of reperfusion in a model of lung transplantation.

High-dose oral CoQ(10) for 7 days produced a 15-fold increase in plasma and a 3-fold increase in lung CoQ(10). In the normoxic lung, the injury-induced rise in peak airway pressure was reduced by CoQ(10) treatment at 90 min (P = 0.037) and at 120 min (P = 0.005) without any change in arterial oxygen. In the lung subjected to severe ischaemia-reperfusion injury, CoQ(10) did not reduce the injury-induced increase in peak airway pressure (P = 0.599) nor the decrease in arterial oxygen (P = 0.844). However, CoQ(10) markedly reduced the increase in tumour necrosis factor-alpha in ischaemic compared with normoxic lung (P = 0.027).

The effect of CoQ(10) pretreatment is insufficient to protect the lung against severe ischaemia-reperfusion as may occur in lung transplantation. However, in the setting of less severe pulmonary injury as in anaesthesia and non-transplant surgery, CoQ(10) may have a protective role.