Trialkyllead compounds induce the opening of the MPT pore in rat liver mitochondria

The interactions of the tributyl, triethyl and trimethyllead compounds with energized mitochondria have been investigated in this paper. It has been shown that the (alkyl)3Pb–Cl compounds induce swelling in mitochondria suspended in a sucrose medium. The phe- nomenon is more marked the higher the lipophilicity and occurs in the following order: (Bu)3Pb > (Et)3Pb > (Me)3Pb. As swelling is inhibited by cyclosporine, this suggests that the swelling is due to the opening of a trans-membrane pore (MTP pore) in the mitochondria. As this pore can be responsible for the inhibition of the ATP synthesis, and, consequently for cell death, the opening of the pore could be one of the reasons for the toxicity of the (alkyl)3Pb–X compounds.