Fig. 2.

Chronic ethanol consumption decreases mitochondrial respiration. A: representative results from oxygen consumption studies from control (gray line) and ethanol (black line) mitochondria. Oxygen consumption was determined using succinate as the oxidizable substrate. ADP was added at the arrow to initiate state 3 respiration (dashed line marking). After all ADP is converted to ATP, mitochondria enter state 4 respiration (lower rate of respiration), which is marked on the trace (dashed line marking). B: state 3 respiration was significantly lower in ethanol mitochondria compared with controls, whereas there was no difference in state 4 respiration between groups. C: the respiratory control ratio (RCR; state 3/state 4 respiration) was significantly lower in ethanol mitochondria compared with controls. Data are expressed as the mean ± SE for 6 pairs of control- and ethanol-fed rats. *P < 0.05 compared with control.