Zinc and copper accumulation and isometallothionein induction in mouse ascites sarcoma S180A cells.
To investigate Zn and Cu accumulation and isometallothionein (iso-MT) induction in ascites-sarcoma S180A cells, 5 micrograms of Zn2+ or Cu2+/g body weight was administered to tumour-bearing mice intraperitoneally. In the tumour cells the Zn or Cu concentration increased more than in the host liver, which is the target organ for those metals; the maximum Zn or Cu level was about 2-3 times that in the host liver. The amounts of Zn-MT or Cu-MT accumulated in the tumour cells and host liver were proportional to such dose accumulation levels in the each cytosol; the maximum level of Zn-MT or Cu-MT was 4 or 2 times higher than in the host liver. MT accumulated in the tumour cells showed two subfractions (MT-1 and MT-2); the ratio of Zn (or Cu) bound to MT-1 to that bound to MT-2 in the host liver and tumour cells was 1.0 (or 1.0) and 0.7 (or 0.25) respectively, suggesting that the induction level of MT-2 in the tumour cells is more than that of MT-1. The h.p.l.c. profiles (using an anion-exchange column) of the isolated MT-1 and MT-2 subfractions from Zn-treated normal-mouse liver showed a single peak (MT-1-1) and two peaks (MT-2-1 and MT-2-2) respectively; mouse MTs were separated into three isoforms. In the ascites cells, the MT fraction obtained by a gel filtration was also separated into three isoforms; however, the amount of MT-2-1 isoform was 3 times that in the Zn-treated normal-mouse liver.
Kobayashi
S
S
Department of Biology, Kyoritsu College of Pharmacy, Tokyo, Japan.
Sayato-Suzuki
J
J
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D003300:Copper / Q000378:metabolism*; D005260:Female; D008099:Liver / Q000378:metabolism; D008668:Metallothionein / Q000378:metabolism*; D051379:Mice; D009368:Neoplasm Transplantation; D012510:Sarcoma 180 / Q000378:metabolism*; D015032:Zinc / Q000378:metabolism*
D000596:Amino Acids; D003300:Copper; D008668:Metallothionein; D015032:Zinc