Depression of liver mitochondrial complex II-linked respiration following cooling: Beneficial effects of using a prostacyclin analogue during hypothermia

The role of mitochondria in the storage and preservation of organs has not fully been investigated. We investigated the hypothesis that the addition of a prostacyclin analogue to preservation solution improved ATP regeneration profiles of stored liver by protecting mitochondrial function. Oxidative phosphorylation was investigated in isolated rat liver mitochondria following a period of cold ischaemic preservation with University of Wisconsin solution plus/minus the prostacyclin analogue, iloprost (10(-8)mol/l). In state 4 respiration (+ substrates -ADP) iloprost doubled oxygen consumption rates for both complex I and II. In state 3 (+ substrates + ADP), iloprost doubled the complex II linked respiration rate, with no significant effect on complex I. Enzyme activity of complex II, measured spectrophotometrically, showed no increase in the presence of iloprost. These results imply that iloprost protects complex II function within the inner mitochondrial membrane during cold ischaemia.