Phenotypes of mice lacking extracellular superoxide dismutase and copper- and zinc-containing superoxide dismutase.
Mice lacking the secreted extracellular superoxide dismutase (EC-SOD) or the cytosolic copper- and zinc-containing SOD (CuZn-SOD) show relatively mild phenotypes. To explore the possibility that the isoenzymes have partly overlapping functions, single and double knockout mice were examined. The absence of EC-SOD was found to be without effect on the lifespan of mice, and the reduced lifespan of CuZn-SOD knockouts was not further shortened by EC-SOD deficiency. The urinary excretion of isoprostanes was increased in CuZn-SOD knockout mice, and plasma thiobarbituric acid-reactive substances levels were elevated in EC-SOD knockout mice. These oxidant stress markers showed potentiated increases in the absence of both isoenzymes. Other alterations were mainly found in CuZn-SOD knockout mice, such as halved glutathione peroxidase activity in the tissues examined and increased glutathione and iron in the liver. There were no changes in tissue content of the alternative superoxide scavenger ascorbate, but there was a 25% reduction in ascorbate in blood plasma in mice lacking CuZn-SOD. No increase was found in the urinary excretion of the terminal metabolites of NO, nitrite, and nitrate in any of the genotypes. In conclusion, apart from the increases in the global urinary and plasma oxidant stress markers, our phenotype studies revealed no other evidence that the copper- and zinc-containing SOD isoenzymes have overlapping roles.
Sentman
Marie-Louise
ML
Department of Medical Biosciences, Clinical Chemistry, Umeå University Hospital, SE-901 85 Umeå, Sweden.
Granström
Micael
M
Jakobson
Håkan
H
Reaume
Andrew
A
Basu
Samar
S
Marklund
Stefan L
SL
D000818:Animals; D000975:Antioxidants / Q000737:chemistry; D001205:Ascorbic Acid / Q000737:chemistry; D001835:Body Weight; D003300:Copper / Q000737:chemistry; D005260:Female; D005838:Genotype; D005936:Glucans / Q000737:chemistry; D005978:Glutathione / Q000737:chemistry / Q000378:metabolism; D007501:Iron / Q000378:metabolism; D028421:Isoprostanes / Q000737:chemistry / Q000652:urine; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009569:Nitric Oxide / Q000737:chemistry; D016877:Oxidants / Q000737:chemistry; D018384:Oxidative Stress; D010641:Phenotype; D013482:Superoxide Dismutase / Q000235:genetics* / Q000378:metabolism; D013481:Superoxides / Q000737:chemistry; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism; D013997:Time Factors; D015032:Zinc / Q000737:chemistry
D000975:Antioxidants; D005936:Glucans; D028421:Isoprostanes; D016877:Oxidants; D017392:Thiobarbituric Acid Reactive Substances; C065495:rice bran saccharide; D013481:Superoxides; D009569:Nitric Oxide; D003300:Copper; D007501:Iron; C499090:Sod3 protein, mouse; D013482:Superoxide Dismutase; D005978:Glutathione; D015032:Zinc; D001205:Ascorbic Acid