[Protective effect of extra metallothioneins from rabbit liver induced by zinc on toxicity of lead in rat primary hepatocyte culture].
Metallothionein (MT), a low-molecular-weight, cysteine-rich, zinc-binding protein, has an important effect in the detoxification of various metals. However, extra Zn7-MT protects aginst the cellular toxicity of lead in rat primary hepatocyte (RPHC) culture has seldom been examined thoroughly. This study was therefore designed to determine the effects of extra Zn7-MT on the toxicity of lead in rat primary hepatocyte culture. Hepatocytes were grown in monolayer culture for 24 h and Zn7-MT was subsequently added for 24 h. RPHC were exposed to different concentration of lead for 24 h. Cytotoxicity was assessed by enzyme leakage and loss of intracellular K+. Meanwhile, the subcellular distribution and accumulation of lead was studied, and the protactive effect on the cellular toxicity of lead in RPHC culture in the present of Zn7-MT was investigated. The results showed that the toxicity of lead was significantly less in the presence of Zn7-MT. The hepatocelluar uptake and accumulation of lead have markedly altered. In the cytosol of control cells, the lead was bound mainly to high-molecular-weight proteins whereas the lead was mainly associated with MT in the presence of extra Zn7-MT.
Hao
Shoujin
S
College of Life Science, Peking University, National Laboratory of Protein Engineering and Plant Genetic Engineering, Beijing 100871, China.
Tian
Peiyao
P
Tang
Qingping
Q
Ru
Binggen
B
D000818:Animals; D002478:Cells, Cultured; D022781:Hepatocytes / Q000166:cytology*; D007854:Lead / Q000633:toxicity*; D008297:Male; D008668:Metallothionein / Q000494:pharmacology*; D011817:Rabbits; D051381:Rats; D017208:Rats, Wistar; D015032:Zinc / Q000494:pharmacology*
D007854:Lead; D008668:Metallothionein; D015032:Zinc