Melatonin significantly improved H/RO-induced retardation of mitochondrial movement in 143B cells and NARP cybrids.

<p>(A, B) Red/green overlay of two consecutive confocal images (Δt = 2min) of 200 nM tetramethylrhodamine methyl ester (TMRM) fluorescence in NARP cybrids and 143B cells in response to H/RO treatment without and with 100 μm melatonin. H/RO (H: 6 h; RO: 2 h) reduced the velocity of mitochondrial movement in both 143B cells and NARP cybrids, so that the percentage of nonmoving mitochondria (overlapping mitochondrial area, in yellow color) to the entire mitochondria were 57 ± 1.4% in 143B cells and 76 ± 1.4% in NARP cybrids as compared to the cells and cybrids, respectively, without H/RO treatment. Adding melatonin 100 μm during H/RO improved mitochondrial movement in both 143B cells and NARP cybrids as compared with the groups without melatonin during H/RO, so that the percentage of nonmoving mitochondria to the all mitochondria was 48 ± 1.2% in 143B cells and 63 ± 2.2% in NARP cybrids. (C) Quantitative analyses of (A). *<i>P</i><0.05. n=6. Mln: melatonin.