GLUCOSE-6-PHOSPHATE-DEHYDROGENASE AND OXIDANT SENSITIVITY OF ERYTHROCYTES OF 3 SPECIES OF WOMBATS

The investigations presented in this paper were undertaken to examine the antioxidant defence systems in the erythrocytes of three extant sp ecies of wombats: the common wombat (CW) (Vombatus ursinus), the south ern 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 dehydrogen ase 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 glu cose 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 t o be more sensitive to oxidant stress as measured by the degree of lip id peroxidation, haemolysis, number of Heinz bodies, and the methaemog lobin formation in the intact cells and/or haemolysates treated with t hree 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.