Table 6.

Mitochondrial function in isolated leukocytes

Melatonin or 6-hydroxymelatonin ng/ml	Mitochondrial membrane potential Red/green fluorescence ratio	Oxygen consumption nMoles O2/min/mg protein	Total radical production ΔFluorescence x 103/min/106 cells	Mitochondrial superoxide production Fluorescence units ×103
Solvent control	23.9 [18.3–27.0]	17.9 [14.2–27.2]	56 [34–61]	260 [250–270]
Melatonin + LPS/PepG	P < 0.0001	P < 0.0001	P < 0.0001	P = 0.0029
0	28.6 [21.1–33.3] #	36.1 [23.0–56.2] #	88 [51–127] #	290 [270–310] #
0.01	21.6 [15.9–24.3]*	27.4 [18.6–38.6]*	59 [39–97]*	280 [270–300]*
0.1	19.9 [15.8–24.3]*	22.6 [16.3–32.4]*	62 [38–80]*	270 [250–300]*
1	21.0 [14.5–25.8]*	24.3 [18.2–41.5]*	62 [37–97]*	270 [260–300]*
10	19.6 [15.6–28.3]*	25.6 [20.5–36.8]*	60 [37–91]*	270 [250–300]*
100	23.2 [15.4–26.7]*	32.4 [25.7–43.4]	59 [35–111]*	270 [250–290]*
1000	24.5 [15.2–28.6]*	37.7 [28.1–48.4]	66 [43–105]*	270 [270–280]*
Solvent control	21.5 [16.1–23.3]	19.0 [14.9–30.9]	57 [41–70]	250 [230–280]
6-Hydroxymelatonin + LPS/PepG	P < 0.0001	P = 0.0037	P < 0.0001	P = 0.0035
0	29.2 [21.8–32.8] #	33.1 [21.1–53.4] #	89 [60–122] #	290 [260–300] #
0.01	21.1 [16.1–23.3]*	19.8 [13.8–26.7]*	76 [45–117]*	270 [250–300]*
0.1	20.4 [17.2–23.9]*	20.0 [12.9–25.2]*	61 [46–108]*	280 [270–300]*
1	21.5 [19.1–26.7]*	18.9 [15.1–25.2]*	68 [40–93]*	280 [260–300]*
10	18.9 [15.8–24.4]*	21.5 [14.8–25.9]*	64 [50–110]*	270 [250–300]*
100	22.2 [18.9–25.0]*	21.3 [15.3–26.7]*	70 [54–109]*	270 [260–300]*
1000	24.6 [16.6–27.8]*	19.4 [16.4–22.6]*	61 [47–72]*	270 [260–290]*

6-OH Melatonin = 6-hydroxymelatonin. Median [interquartile range], n = 20. P-value shown is Friedman's test across LPS/PepG groups.

^#Significantly different from solvent control (Wilcoxon signed ranks) and ^*significantly different from LPS/PepG alone (Dunn's test) P < 0.05.