Use of the fluorescent probe, 1-anilino-8-naphthalene sulfonate, to monitor the interaction of pesticide chemicals with mitochondrial membranes.

1. The interaction of mitochondrial and submitochondrial membranes with DDT, methoxychlor and kelthane as monitored by fluorescence changes of ANS was studied. 2. The three organochlorine pesticide chemicals reduced the succinate- and ATP-dependent quenching of ANS fluorescence of mitochondria in a concentration-dependent manner. The results suggest that they blocked the supply of energy to the inner membrane. 3. The reversal of the substrate-induced quenching of ANS by uncouplers was abolished by DDT and kelthane probably as a consequence of the inhibition of protonophoric activity of the uncoupler. 4. Both DDT and kelthane were relatively ineffective inhibitors of substrate-induced quenching of ANS fluorescence of submitochondrial particles. The results suggest an asymmetry of the inner membrane with respect to DDT-inhibition of substrate-induced energization. 5. The possible basis of this asymmetry as well as of inhibition of energy supply to the membrane is discussed.