TABLE 1.

Effect of temperature on mitochondrial metabolism and H₂O₂ production.

	Temperature (°C)			Statistical analysis
	20	25	30	F-values	P-values
Oxygen consumption rate (nmol O min –1 mg protein –1)
Basal state	3.90.4	5.20.7*	7.01.0†	15.7
Active state	12.81.7	16.52.5*	21.12.7†	38.2
Maximal ETS	18.22.5	20.92.6	25.63.6†	9.6
ATP synthesis rate (nmol ATP min–1 mg protein–1)
Active state	13.61.9	16.42.3*	20.73.3†	15.2	p < 0.01
H2O2 generation rate (pmol H2O2 min–1 mg protein–1)
Basal state	13316	17817*	24024†	38.8	p < 0.0001
Active state	738	939*	1558†	255.5	p < 0.0001
Free electron leak (%H2O2/O)
Basal state	3.30.2	3.50.2	3.50.3	n.s.	n.s.
Active state	0.590.04	0.600.06	0.770.08†	8.5	p < 0.05

The mitochondrial oxygen consumption rates and the H₂O₂ production were measured in isolated liver mitochondria fueled with succinate alone (basal state) or with ADP (active state) or with FCCP in the presence of oligomycin (maximal ETS, maximal activity of the electron transport system). Free electron leak is the percent of oxygen turned into H₂O₂ instead of H₂O (%H₂O₂/O). The values are expressed as means ± SEM (N = 5). *p < 0.05 versus 20°C; ^†p < 0.05 versus 25°C.