Mechanism of the stimulation of respiration by fatty acids in rat liver.

The mechanism of stimulation of hepatic respiration by fatty acids was studied in isolated rat hepatocytes. Stimulation of respiration by fatty acids varied from about 35% to about 105% depending on chain length. The stimulatory effect of octanoate (1 mM) or oleate (0.5 mM) was prevented by oligomycin (2 micrograms/ml). With carboxyatractyloside (100 microM) and ouabain (2 mM) the stimulation of respiration was partially inhibited (by 50-70 and 50-60%, respectively). From these results it can be concluded that the increased rate of respiration after addition of fatty acids is coupled to ATP synthesis. A large part (50-60%) of this ATP is utilized by the (Na+ + K+)-ATPase.