Chauncey B, Schmid E C, Goldstein L
Division of Biology and Medicine, Brown University, Providence, Rhode Island 02912.
J Toxicol Environ Health. 1988;23(2):257-65. doi: 10.1080/15287398809531111.
The effects of mercurials and arsenicals on tyrosine absorption by the winter flounder Pseudopleuronectes americanus were studied using isolated intestinal strips mounted in Ussing chambers. The mercurials mercuric chloride (HgCl2), p-chloromercuriphenyl sulfonic acid (PCMBS), and phenylmercuric acetate (PMA) and the arsenicals oxophenylarsine and arsenamide were chosen for their different chemical properties. The transmural absorptive fluxes (mucosa to serosa, M----S) were inhibited by mucosal additions of 0.1 mM HgCl2 (64% inhibition), 1.0 mM PCMBS (41% inhibition), and 0.25 mM oxophenylarsine (48% inhibition). Tyrosine tissue accumulation was inhibited 68% by 0.1 mM HgCl2, 42% by 1.0 mM PCMBS, and 62% by 0.25 mM oxophenylarsine. Serosal addition of 1.0 mM PCMBS inhibited M----S flux by 45%. Transepithelial potential (TEP) was measured to monitor changes in ionic gradients across the epithelial membrane. Mucosal addition of 0.1 mM HgCl2, and of 0.25 and 0.05 mM oxophenylarsine significantly changed the TEP. Serosal additions of 0.1 mM HgCl2, 1.0 mM PCMBS, and 0.25 mM oxophenylarsine also altered the TEP significantly. These results indicate that Na+-dependent tyrosine uptake is inhibited by arsenicals and mercurials, but it is unclear whether the Na+-tyrosine cotransport system or the transmembrane ionic gradients were affected by these heavy metals.
利用安装在尤斯灌流室中的分离肠段，研究了汞化合物和砷化合物对美洲拟庸鲽（Pseudopleuronectes americanus）酪氨酸吸收的影响。选择汞化合物氯化汞（HgCl2）、对氯汞苯磺酸（PCMBS）和醋酸苯汞（PMA）以及砷化合物氧苯胂和砷酰胺，是因其具有不同的化学性质。向黏膜侧添加0.1 mM HgCl2（抑制64%）、1.0 mM PCMBS（抑制41%）和0.25 mM氧苯胂（抑制48%）可抑制跨膜吸收通量（从黏膜到浆膜，M→S）。0.1 mM HgCl2使酪氨酸组织蓄积抑制68%，1.0 mM PCMBS使其抑制42%，0.25 mM氧苯胂使其抑制62%。向浆膜侧添加1.0 mM PCMBS可使M→S通量抑制45%。测量跨上皮电位（TEP）以监测跨上皮膜离子梯度的变化。向黏膜侧添加0.1 mM HgCl2以及0.25 mM和0.05 mM氧苯胂可显著改变TEP。向浆膜侧添加0.1 mM HgCl2、1.0 mM PCMBS和0.25 mM氧苯胂也可显著改变TEP。这些结果表明，砷化合物和汞化合物可抑制Na+依赖的酪氨酸摄取，但尚不清楚这些重金属影响的是Na+ - 酪氨酸共转运系统还是跨膜离子梯度。
