Effect of chronic aurothioglucose treatment of rats on kidney catalase and cytochromes.
Catalase activity and cytochrome content were measured in kidneys of Fisher 344 rats injected with aurothioglucose (ATG) either daily for 3 days or 5 days a week for up to 8 wk. Catalase activity was decreased 39%, 59%, and 48% (all p less than 0.001) after 3 days, 2 wk, and 8 wk, respectively. Microsomal cytochrome P-450 levels decreased 71%, 86%, and 80% (all p less than 0.001) after 3 days, 2 wk, and 8 wk, respectively. In contrast, cytochrome b5 was significantly increased at 3 days and 2 wk, but not at 8 wk. Microsomal heme contents decreased 44% (p less than 0.001), 34% (p less than 0.001), and 22% (p greater than 0.05) at 3 days, 2 wk, and 8 wk, respectively. The content of mitochondrial cytochromes aa3, b, c1, and c were not affected after 8 wk of ATG treatment. In vitro inhibition of the heme-containing enzyme delta-aminolevulinic acid dehydratase by ATG was reversible in the presence of physiological concentrations of small thiols. Although the activity of this enzyme in kidneys of ATG-treated rats was not measured, its significant inhibition in vivo by ATG appears unlikely. This study demonstrates that there were differential effects of gold on the various cytochromes and that changes in catalase activity paralleled changes in cytochrome P-450 and heme contents in the kidneys of ATG-treated rats. The findings are relevant to nephrotoxicity during chrysotherapy.
D000818:Animals; D006051:Aurothioglucose / Q000494:pharmacology*; D001835:Body Weight / Q000187:drug effects; D002374:Catalase / Q000378:metabolism*; D003580:Cytochromes / Q000378:metabolism*; D006046:Gold / Q000494:pharmacology*; D007668:Kidney / Q000201:enzymology*; D008861:Microsomes / Q000201:enzymology*; D008928:Mitochondria / Q000201:enzymology*; D051381:Rats; D011916:Rats, Inbred F344
D003580:Cytochromes; D006051:Aurothioglucose; D006046:Gold; D002374:Catalase