title: Comparative study of the antioxidant defence systems in the erythrocytes of Australian marsupials and monotremes.
abstract: A comparison of the erythrocyte (RBC) antioxidant metabolites and enzymes in nine marsupial and two monotreme species was carried out. Reduced glutathione (GSH) concentrations were comparable with those reported for other marsupial and eutherian species. An important finding was that the erythrocytes of the southern hairy nosed wombat regenerated GSH faster than the erythrocytes from its close relative, the common wombat. The activities of glutathione-S-transferase, NADH-methaemoglobin reductase, superoxide dismutase, and glutathione peroxidase (GSH-Px), showed similar levels and extents of variation as those observed in other marsupial and eutherian species. Catalase activities in the marsupials were lower than those measured in the two monotreme species and much lower than those reported in eutherian species. A negative correlation, significant at P < 0.05, was observed between GSH-Px and catalase activities in the RBC of the marsupials. Since both these enzymes "detoxify" H2O2, there appears to be a reciprocal relationship between the activities of these enzymes in marsupial RBC.
authors.affiliation: Department of Physiology, University of New England, Armidale, NSW, Australia.
authors.forename: A T
authors.initials: AT
authors.lastname: Whittington
authors.forename: A L
authors.initials: AL
authors.lastname: Parkinson
authors.forename: P B
authors.initials: PB
authors.lastname: Spencer
authors.forename: G
authors.initials: G
authors.lastname: Grigg
authors.forename: L
authors.initials: L
authors.lastname: Hinds
authors.forename: C H
authors.initials: CH
authors.lastname: Gallagher
authors.forename: P W
authors.initials: PW
authors.lastname: Kuchel
authors.forename: N S
authors.initials: NS
authors.lastname: Agar
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D001315:Australia; D002374:Catalase / Q000097:blood; D042966:Cytochrome-B(5) Reductase / Q000097:blood; D004798:Enzymes / Q000097:blood*; D004912:Erythrocytes / Q000201:enzymology* / Q000502:physiology; D005978:Glutathione / Q000097:blood; D005979:Glutathione Peroxidase / Q000097:blood; D005982:Glutathione Transferase / Q000097:blood; D006861:Hydrogen Peroxide / Q000097:blood; D008394:Marsupialia / Q000097:blood*; D009007:Monotremata / Q000097:blood*; D009243:NAD / Q000097:blood; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D013045:Species Specificity; D013482:Superoxide Dismutase / Q000097:blood
chemical_list: D000975:Antioxidants; D004798:Enzymes; D009243:NAD; D006861:Hydrogen Peroxide; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D042966:Cytochrome-B(5) Reductase; D005982:Glutathione Transferase; D005978:Glutathione