UPTAKE OF CHROMIUM BY RAT-LIVER MITOCHONDRIA
UPTAKE OF CHROMIUM BY RAT-LIVER MITOCHONDRIA
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DOI：
10.1016/0300-483x(82)90050-6
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发表时间：
1982-01-01
期刊：
影响因子：
4.5
通讯作者：
NORSETH, T
中科院分区：
文献类型：
--
作者：
ALEXANDER, J;AASETH, J;NORSETH, T
分离的大鼠肝线粒体迅速积累铬酸盐（1.2 μ M 51 CrO 42-）至约0.25-0.30 nmol Cr/mg蛋白。相对摄取随铬酸盐剂量增加而降低。当pH从7.0升高到7.5时，铬酸盐吸收降低。N-乙基马来酰亚胺（0.25 mM）和丙二酸丁酯（5 mM）分别将铬酸盐摄取抑制至对照值的70%和30%，而汞撒利（40 nmol/kg蛋白质）引起> 95%的抑制。硫酸盐和磷酸盐降低线粒体铬酸盐摄取，前者在较低剂量（5 mM）下更有效。铬酸盐的转运介导的二羧酸和磷酸载体。广泛的线粒体铬的积累被解释为捕获的铬，可能是通过减少铬酸盐的三价形式，在线粒体内。铬酸盐加载后释放的铬被视为15分钟后。加入铬酸盐加载后，汞撒利部分防止这种释放。以51 CrCl 3形式的Cr（III）被吸收的程度低于以51 CrO 42-形式的Cr（VI）。谷胱甘肽（[GSH] 5 mM）的存在下，51 Cr（III）和51 Cr（VI）的摄取减少，表明线粒体外还原Cr（VI）为Cr（III），随后结合到GSH。
Isolated rat liver mitochondria rapidly accumulated chromate (1.2 .mu.M 51CrO42-) to .apprx. 0.25-0.30 nmol Cr/mg protein. The relative uptake decreased with increased chromate doses. Chromate uptake decreased when pH was raised from 7.0 to 7.5. N-ethylmaleimide (0.25 mM) and butylmalonate (5 mM) inhibited chromate uptake to 70 and 30% of control values, respectively, whereas mersalyl (40 nmol/kg protein) caused an inhibition of > 95%. Sulfate and phosphate decreased mitochondrial chromate uptake, the former being more effective in lower doses (5 mM). Transport of chromate was mediated on the dicarboxylate and the phosphate carrier. The extensive mitochondrial Cr accumulation was explained by trapping of Cr, probably by reduction of chromate to the trivalent form, within the mitochondria. Release of Cr after chromate loading was seen after 15 min. Added after chromate loading mersalyl partly prevented this release. Cr(III) as 51CrCl3 was taken up to a lower degree than Cr(VI) as 51CrO42-. The presence of glutathione ([GSH] 5 mM) reduced the uptake 51Cr(III) and 51Cr(VI), indicating extramitochondrial reduction of Cr(VI) to Cr(III) and subsequent binding to GSH.