Elevation of hepatic metallothionein in rats chronically exposed to dietary ethionine.
Following 30 weeks of exposure to 0.3% ethionine in the diet, male Fischer rats bearing liver cell tumors showed a marked increase (9.5 fold) in hepatic metallothionein (MT) concentrations relative to control, as assessed by the cadmium-hemoglobin assay. To confirm the presence of MT in the tumor-containing livers of ethionine-fed rats, biochemical analyses were performed. Spectral analysis of a purified protein from ethionine-treated livers revealed a UV absorption spectrum characteristic of MT. Gel filtration (Sephadex G-75) indicated a prominent copper (Cu) and zinc (Zn)-containing peak with a Mr (approx. 9 000) similar to that of MT. Concurrent with the elevation in hepatic MT in ethionine-fed rats there was an increase in the concentration of Cu and Zn in hepatic cytosol.
D000818:Animals; D002850:Chromatography, Gel; D003300:Copper / Q000378:metabolism; D004032:Diet; D005001:Ethionine / Q000633:toxicity*; D008099:Liver / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D008668:Metallothionein / Q000378:metabolism*; D051381:Rats; D011916:Rats, Inbred F344; D013054:Spectrophotometry, Atomic; D013056:Spectrophotometry, Ultraviolet; D013997:Time Factors; D015032:Zinc / Q000378:metabolism
D003300:Copper; D008668:Metallothionein; D015032:Zinc; D005001:Ethionine