ABSTRACT
BACKGROUND: Antioxidant enzyme status changes in experimental models of chronic renal disease with glomerulosclerosis. Most of the studies are performed in rats. We now investigate whether a mouse model with more rapid development of glomerulosclerosis is suitable for the study of radical-associated renal disease. METHODS: Female BALB/c mice are injected intravenously with a single dose of adriamycin (10 mg/kg). The development of glomerular and interstitial injury is evaluated by means of renal function parameters and histology. Renal cortex activities of catalase, Cu/Zn and Mn superoxide dismutase and glutathione peroxidase are measured by enzymatic techniques, and their mRNA levels by Northern blot analysis. RESULTS: The mice develop proteinuria and hypercholesterolaemia; glomerulosclerosis is present 20 days after adriamycin injection. Involvement of reactive oxygen intermediates in the disease process is supported by an increased cortex level of glutathione (1.77+/-0.13 vs 1.31+/-0.12 micromol/g kidney; P = 0.021) and ferric iron deposition in the tubulointerstitial compartment. Glomerulosclerosis and tubulointerstitial lesions are accompanied by decreased cortex activities of catalase (0.19+/-0.01 vs 0.23+/-0.01 U/mg protein; P = 0.024), glutathione peroxidase (0.28+/-0.01 vs 0.32+/-0.01 U/mg protein; P = 0.049) and Mn superoxide dismutase (6.61+/-0.91 vs 9.25+/-0.99 U/mg protein, P = 0.020). We find decreased cortex mRNA levels only for glutathione peroxidase. CONCLUSION: The fast development of glomerulosclerosis combined with an altered antioxidant status makes this mouse adriamycin model a suitable alternative for the slower rat models.
Subject(s)
Antioxidants/metabolism , Glomerulosclerosis, Focal Segmental/enzymology , Animals , Catalase/genetics , Catalase/metabolism , Disease Models, Animal , Doxorubicin/toxicity , Female , Glomerulosclerosis, Focal Segmental/chemically induced , Glomerulosclerosis, Focal Segmental/genetics , Glomerulosclerosis, Focal Segmental/pathology , Glutathione Peroxidase/genetics , Glutathione Peroxidase/metabolism , Kidney Cortex/enzymology , Mice , Mice, Inbred BALB C , Oxidative Stress , RNA, Messenger/genetics , RNA, Messenger/metabolism , Rats , Reactive Oxygen Species/metabolism , Species Specificity , Superoxide Dismutase/genetics , Superoxide Dismutase/metabolism , Time FactorsABSTRACT
Excessive generation of reactive oxygen intermediates can induce changes in the cellular antioxidant defence system. In this study we examine the antioxidant enzyme status and the expression of fibrosis-related marker proteins in the Adriamycin model of chronic renal failure in the rat. Twenty weeks after Adriamycin treatment, rats have overt nephrotic syndrome and renal failure with development of tubulo-interstitial fibrosis and glomerulosclerosis. Lipids accumulate in blood and in both glomeruli and tubulo-interstitial tissue. Desmin and alpha-smooth muscle actin expression increases in glomeruli and in the tubulo-interstitial area. Renal cortex antioxidant enzyme activities are decreased 20 weeks after Adriamycin injection (to 41% for catalase, to 56% for total superoxide dismutase and to 69% for glutathione peroxidase). The mRNA levels of catalase, Cu/Zn-superoxide dismutase and glutathione peroxidase-1 evaluated by Northern blot are decreased by more than 50% for catalase, Cu/Zn-superoxide dismutase and glutathione peroxidase-1. We conclude that in the rat Adriamycin-induced model of chronic renal failure with fibrosis, the combination of decreased antioxidant enzyme status in renal cortex with high concentrations of lipids in blood and renal tissue facilitates oxidative damage. Development of fibrosis is paralleled by increased expression of desmin and alpha-smooth muscle actin.
Subject(s)
Catalase/metabolism , Doxorubicin/toxicity , Glutathione Peroxidase/metabolism , Kidney/enzymology , Kidney/pathology , Superoxide Dismutase/metabolism , Animals , Biomarkers/analysis , Blood Pressure/drug effects , Catalase/genetics , Desmin/analysis , Desmin/genetics , Fibrosis , Glutathione Peroxidase/genetics , Hemodynamics/drug effects , Kidney/drug effects , Kidney Cortex/enzymology , Male , Models, Animal , Nephrotic Syndrome/chemically induced , Nephrotic Syndrome/enzymology , Nephrotic Syndrome/pathology , Rats , Rats, Wistar , Reference Values , Renal Insufficiency/chemically induced , Renal Insufficiency/enzymology , Renal Insufficiency/pathology , Superoxide Dismutase/genetics , Time Factors , Transcription, GeneticABSTRACT
Reactive oxygen intermediates play a role in chronic renal injury and glomerulosclerosis. We investigate changes in renal cortex antioxidant enzyme gene expression in the rat remnant-kidney model of chronic renal failure and compare the new data to enzyme activities published earlier. Antioxidant enzyme gene expression is evaluated by Northern blot analysis of cortex mRNA, using cDNA probes for catalase, copper/zinc-containing superoxide dismutase, and glutathione peroxidase. Catalase gene expression decreases during development of renal failure; this decrease is accompanied by decreased catalase activity during the glomerulosclerosis phase of the remnant-kidney model. Copper/zinc superoxide dismutase and glutathione peroxidase gene expression remain at a normal level during progression of the model, whereas their activities show a temporary decrease in the early remnant kidney. In the remnant-kidney model, catalase seems to be more vulnerable to reactive oxygen intermediates than superoxide dismutase and glutathione peroxidase. Our results show that antioxidant enzyme activity and gene expression do not change in the same direction at all times during disease development and that all antioxidant enzymes do not respond in the same way.
