Rat liver glutathione S-transferase activity stimulation following acute cadmium or manganese intoxication.
The effect of cadmium or manganese administration on rat liver glutathione S-transferase (GST) has been investigated. The activity of this enzyme in liver cytosol, where almost all the cellular activity is present, had increased by more than 36% 24 h after a single i.p. injection of CdCl(2) (2.5 mg kg(-1) b.w.) or MnCl(2) (2.0 mg kg(-1) b.w.). After shorter and longer time intervals, a lower enzyme activity stimulation was observed in both cases. When liver cytosol was incubated for 10 min with 75 microM CdCl(2) or 40 microM MnCl(2), no effect was observed on enzyme activity. The increase in GST following cadmium or manganese administration was blocked by prior administration of actinomycin D, indicative of a possible transcription-dependent response. The liver soluble GST from both control and metal-treated rats was not at all affected by Vitamin E, in the range of 20-300 microM. By contrast, hematin was seen to be a competitive inhibitor of this liver enzyme from both types of rats by using CDNB as substrate and the K(i) value was equal to 0.22 microM. The possibility that under the conditions used class alpha GST isoenzymes are affected by cadmium or manganese is discussed.
Casalino
Elisabetta
E
Sezione di Chimica e Biochimica Veterinaria del Dipartimento Farmaco-Biologico, Università degli Studi di Bari, Str. Prov. per Casamassima, Km 3, 70010 Valenzano, Bari, Italy.
Sblano
Cesare
C
Landriscina
Vito
V
Calzaretti
Giovanna
G
Landriscina
Clemente
C
D000818:Animals; D019256:Cadmium Chloride / Q000633:toxicity*; D002712:Chlorides / Q000633:toxicity*; D003600:Cytosol / Q000187:drug effects / Q000201:enzymology; D004347:Drug Interactions; D004790:Enzyme Induction / Q000187:drug effects; D005982:Glutathione Transferase / Q000096:biosynthesis*; D006427:Hemin / Q000494:pharmacology; D015227:Lipid Peroxidation / Q000187:drug effects; D008099:Liver / Q000187:drug effects* / Q000201:enzymology; D008297:Male; D017895:Manganese Compounds; D051381:Rats; D017208:Rats, Wistar; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism; D014810:Vitamin E / Q000494:pharmacology
D002712:Chlorides; D017895:Manganese Compounds; D017392:Thiobarbituric Acid Reactive Substances; D014810:Vitamin E; D006427:Hemin; D005982:Glutathione Transferase; D019256:Cadmium Chloride; C025340:manganese chloride