Glucose-6-phosphate dehydrogenase and oxidant sensitivity of erythrocytes of three species of wombats

The investigations presented in this paper were undertaken to examine the antioxidant defence systems in the erythrocytes of three extant species of wombats: the common wombat (CW) (Vombatus ursinus), the southern hairy-nosed wombat (SHW) (Lasiorhinus latifrons) and the northern hairy-nosed wombat (NHW) (Lasiorhinus krefftii). Some of the important observations were: (1) the activity of glucose-6-phosphate dehydrogenase was 5.14 +/- 0.96 enzyme units/g haemoglobin (EU/gHb) in CW, 35.69 +/- 1.02 EU in SHW and 30.71 +/- 1.49 EU in NHW and the levels of glucose phosphate isomerase were 40.1 +/- 3.39, 93.2 +/- 1.96 and 74.9 +/- 4.9 EU/gHb, respectively and (2) the erythrocytes of CW were found to be more sensitive to oxidant stress as measured by the degree of lipid peroxidation, haemolysis, number of Heinz bodies, and the methaemoglobin formation in the intact cells and/or haemolysates treated with three different oxidising agents-acetylphenylhydrazine, sodium nitrite and hydrogen peroxide. The CW lives in a temperate environment and the SHW, and NHW live in arid to semi-arid environments. The consequences in terms of antioxidant defence requirements are discussed.