Inhibition of brain macrophage/microglial respiratory chain enzyme activity in experimental autoimmune encephalomyelitis of the Lewis rat.

We measured the activities of five respiratory chain enzymes in brain macrophages/microglial cells from Lewis rats with experimental autoimmune encephalomyelitis (EAE) and found a significant reduction of the activity of nicotinamide adenine dinucleotide-dehydrogenase (NADH-DH), succinate cytochrome c reductase (SCCR) and succinate dehydrogenase (SDH) when compared with age-matched healthy control animals. The inhibition of NADH-DH (complex I) was specific for EAE, while we also found a reduction of SCCR and SDH activities (complex II) in newborn rats and adjuvant-immunised rats. Activities of NADH cytochrome c reductase (NCCR) and cytochrome c oxidase (COX) were not significantly changed. These observations demonstrate an impairment of brain macrophage/microglial respiratory chain function in central nervous system inflammation.