Lysis of normal and reduced glutathione-deficient sheep erythrocytes by tellurite and selenite [proceedings].

Mammalian erythrocytes normally contain high concentrations of the tripeptide GSH.* The major role of G S H in these cells is t o protect against oxidative damage, the GSH-GSSG coupleactingasaredox bufferingsystem. Sheepexhibit two distinct types of inherited erythrocyte GSH deficiency. One type is associated with a diminished activity of y-glutamyl-cysteine synthetase, the first enzyme of GSH biosynthesis (Young & Nimmo, 1975). The second type of GSH deficiency is due to the lack of availability of cysteine, a component amino acid of glutathione, resulting from the absence of a specific amino acid-transport system (Young et al., 1975,1976; Young & Ellory, 1977). Both lesions can be found in the same animal, and erythrocytes from such ‘double-low’ GSH sheep have a lower GSH concentration than that found with either type of deficiency alone (Tucker et al., 1976). Lysis of erythrocytes has been shown to occur in the presence of tellurite (Blais et al., 1972), and intracellular G S H appears t o be involved in the lytic process (DeMeio & Onischuk, 1974). We have investigated this phenomenon further by studying the effects of tellurite and the closely related selenite on normal and GSH-deficient erythrocytes from sheep.