Bondy S C, Agrawal A K
Arch Toxicol. 1980 Dec;46(3-4):249-56. doi: 10.1007/BF00310441.
The effect of various concentrations of several lead and mercury compounds upon various high affinity receptor sites within discrete brain regions has been measured. The specific binding of radioactive spiroperidol and quinuclidinyl benzilate to striatal and cortical membranes respectively, was much more severely inhibited in the presence of tri-n-butyl lead acetate than by lead acetate. This suggested that the hydrophobic organic lead derivative was able to interfere with receptor structure more readily than the lead acetate. On the other hand mercuric chloride was more effective in blocking these two neurotransmitter receptor sites than was the organic methylmercuric chloride. This implied that sulfhydryl groups may be within, or proximal to the allosteric binding site. The relative ineffectiveness of all heavy metal compounds studied in blocking the glycine. GABA or the diazepam receptors indicated that the mechanism of binding may not be similar with different receptor proteins. Since micromolar concentrations of some lead and mercury compounds suffice to severely inhibit neurotransmitter binding sites, such a direct interference with postsynaptic events may in part account for the neurological consequences of heavy metal poisoning.
已测定了几种铅和汞化合物的不同浓度对离散脑区中各种高亲和力受体位点的影响。放射性螺哌啶醇和喹核醇基苯甲酸酯分别与纹状体膜和皮质膜的特异性结合，在三正丁基醋酸铅存在下比在醋酸铅存在下受到的抑制要严重得多。这表明疏水性有机铅衍生物比醋酸铅更易干扰受体结构。另一方面，氯化汞在阻断这两个神经递质受体位点方面比有机甲基氯化汞更有效。这意味着巯基可能位于别构结合位点内或其附近。所研究的所有重金属化合物在阻断甘氨酸、γ-氨基丁酸或地西泮受体方面相对无效，这表明不同受体蛋白的结合机制可能不同。由于微摩尔浓度的一些铅和汞化合物足以严重抑制神经递质结合位点，这种对突触后事件的直接干扰可能部分解释了重金属中毒的神经学后果。
