艾氏腹水癌细胞中氯离子和硫酸根离子的转运：共同机制的证据
Chloride and sulfate transport in Ehrlich ascites tumor cells: evidence for a common mechanism.
作者信息
Levinson C
出版信息
J Cell Physiol. 1978 Apr;95(1):23-32. doi: 10.1002/jcp.1040950104.
The effects of phloretin, H2DIDS (4,4'-diisothiocyano-1,2-diphenylethane-2,2'-disulfonate) and SO4-2 on anion transport in Ehrlich ascites tumor cells was studied in an effort to determine whether Cl- and SO4-2 share a common transport mechanism. Sulfate, in the presence of constant extracellular Cl- (100 mM), reduces Cl- self-exchange by 43% (40 mM SO4-2) and Cl--SO4-2 exchange by 36% (25 mM Cl-/O SO4-2 compared to 25 mM Cl-/50 mM SO4-2). Phloretin blocks without delay and to the same extent the self-exchange of both Cl- and SO4-2. For example, at 10(-4) M phloretin, anion transport is inhibited 28% which increases to 78% at 5 X 10(-4) M. Reversibly bound H2DIDS also inhibits the self-exchange of both Cl- and SO4-2. However, at all H2DIDS concentrations tested (0.5 - 10 X 10(-5) M) SO4-2 transport was far more susceptible to inhibition than that of Cl-. H2DIDS when irreversibly bound to the cell inhibits SO4-2 but not Cl- transport. The results of these experiments are consistent with the postulation that both Cl- and SO4-2 are transported by a common mechanism possessing two reactive sites.
为了确定氯离子（Cl⁻）和硫酸根离子（SO₄²⁻）是否共享一种共同的转运机制，研究了根皮素、H2DIDS（4,4'-二异硫氰基-1,2-二苯乙烷-2,2'-二磺酸盐）和硫酸根离子（SO₄²⁻）对艾氏腹水癌细胞中阴离子转运的影响。在细胞外氯离子（Cl⁻）浓度恒定为100 mM的情况下，硫酸根离子（SO₄²⁻）会使氯离子（Cl⁻）的自交换减少43%（40 mM SO₄²⁻时），使氯离子（Cl⁻）与硫酸根离子（SO₄²⁻）的交换减少36%（25 mM Cl⁻/0 mM SO₄²⁻与25 mM Cl⁻/50 mM SO₄²⁻相比）。根皮素能立即且同等程度地阻断氯离子（Cl⁻）和硫酸根离子（SO₄²⁻）的自交换。例如，在10⁻⁴ M根皮素时，阴离子转运被抑制28%，在5×10⁻⁴ M时增加到78%。可逆结合的H2DIDS也抑制氯离子（Cl⁻）和硫酸根离子（SO₄²⁻）的自交换。然而，在所有测试的H2DIDS浓度（0.5 - 10×10⁻⁵ M）下，硫酸根离子（SO₄²⁻）的转运比氯离子（Cl⁻）的转运更容易受到抑制。当H2DIDS不可逆地结合到细胞上时，它会抑制硫酸根离子（SO₄²⁻）的转运，但不抑制氯离子（Cl⁻）的转运。这些实验结果与氯离子（Cl⁻）和硫酸根离子（SO₄²⁻）通过具有两个反应位点的共同机制进行转运的假设一致。
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