ABSTRACT
This chapter reviews the existing knowledge of the reaction of the di- and triorganolead compounds with mitochondria, certain enzymes, and other macromolecules. In the diorganolead and diorganotin compounds, the major determinant of toxicity and biological activity is their affinity for dithiol groups to form a stable five-membered ring. Evidence is well established that dialkyltin compounds react with the pyruvate and a-oxyglutarate oxidase complex to cause inhibition. Triorganolead compounds influence mitochondrial functions, and several mechanisms can be distinguished experimentally. The mechanisms by which triorganoleads act on mitochondrial functions measured in a chloride-containing medium are not fully understood but probably are mainly the consequences of a decreased pH and an increased concentration of chloride ion within the mitochondrion. Triorganotins and triorganoleads cause a rapid and extensive swelling of mitochondria in a potassium isethionate medium. Other evidence indicates that certain enzymes located on membranes, such as the sodium/potassium-activated ATPase and the calcium-activated ATPase of muscle, are inhibited by triorganotin compounds.
