Enhancement of gamma-glutamylcysteine synthetase mRNA in rat kidney by methyl mercury.
Glutathione (GSH), a major cellular antioxidant, is elevated 2- to 3-fold in kidneys of rats during prolonged treatment with mercury as methyl mercury hydroxide (MMH). Increased renal GSH is accompanied by a dose- and time-related elevation in the relative abundance of mRNA hybridizable to a cDNA probe which encodes renal gamma-glutamylcysteine synthetase (GCS), the rate-limiting enzyme in GSH synthesis. Renal GCS mRNA is maximally elevated 4.4-fold at 3 weeks following initiation of MMH treatment. Enhancement of GSH and GCS mRNA content corresponds to a relative sparing of renal cells from oxidative tissue damage during MMH exposure. These observations suggest that increased synthesis of GSH at the genetic level occurs as an initial adaptive response to mercury-induced oxidative stress in kidney cells.
Department of Environmental Health, School of Public Health and Community Medicine, University of Washington, Seattle 98195.
J S
JS
Woods
H A
HA
Davis
R P
RP
Baer
D000818:Animals; D015342:DNA Probes; D005721:Glutamate-Cysteine Ligase / Q000235:genetics* / Q000378:metabolism*; D005978:Glutathione / Q000378:metabolism; D007668:Kidney / Q000187:drug effects / Q000201:enzymology*; D007700:Kinetics; D008767:Methylmercury Compounds / Q000494:pharmacology*; D015347:RNA Probes; D012333:RNA, Messenger / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D051381:Rats; D011916:Rats, Inbred F344; D013997:Time Factors
D015342:DNA Probes; D008767:Methylmercury Compounds; D015347:RNA Probes; D012333:RNA, Messenger; D005721:Glutamate-Cysteine Ligase; C020771:methylmercury hydroxide; D005978:Glutathione