Methaemoglobin formation in the koala and the possum

Measurements were made of glutathione (GSH) levels, catalase activity and the oxidant sensitivity of the erythrocytes from the koala (Phascolarctos cinereus) and the common brushtail possum (Trichosurus vulpecula). The oxidant sensitivity was tested by treating the haemolysates with either 0.55 him H^sub 2^O^sub 2^ or 1.4mm NaNO^sub 2^. The erythrocytes of the koala had greater levels of GSH and catalase and yet were found to be more susceptible to oxidation induced by both these oxidants.[PUBLICATION ABSTRACT]