UNCOUPLING EFFECT OF DICARBOXYLIC ANALOGS OF STEARIC AND PALMITIC ACIDS IN HEART-MITOCHONDRIA

The uncoupling effect of 2-hexadecylmalonic acid (HDMA)(4) and 2-tetra decylmalonic acid (TDMA), the dicarboxylic derivatives of stearic and palmitic acids, were studied in heart mitochondria. The effects of the se substances and related fatty acids on Delta psi generated by ascorb ate oxidation with PMS (or TMPD) in the presence of oligomycin, phosph ate, and rotenone were compared. It was found that both HDMA and TDMA uncoupled mitochondria with a similar efficiency as the corresponding fatty acids, while the uncoupling effect of low concentrations of HDMA and TDMA was almost completely suppressed by carboxyatractylate.