Reserpine as an uncoupling agent
1. Reserpine, like the uncoupling agent, 2,4-dinitrophenol prevents oxidative phosphorylation but stimulates the rate at which oxygen is reduced. 2. Both reserpine and 2,4-dinitrophenol fail to stimulate oxygen uptake by isolated mitochondria in the presence of arginine. 3. Both 2,4-dinitrophenol and reserpine induce proton permeability in the mitochondrial membrane so that H+ is absorbed from the suspending medium. 4. When the reaction system contains reserpine, accumulation of Ca2+ by mitochondria is inhibited. 5. Reserpine decreases both ADP:O and P:O ratios which strongly suggest that reserpine is an uncoupling agent.