铅接触者单胺类神经生化的改变

铅接触者暴露于0.56±0.46 mg/m~3空气铅180d,血铅达到3.57～3.98μmol/L时,FEP含量超过正常值上限4～6倍。外周血淋巴细胞DA受体含量降低,尿液HVA排泄量增加以及血小板主动摄取[~3H]5-HT能力下降。提示铅可影响人体单胺类神经元的生化过程,干扰DA神经递质,可能是铅中毒某些神经行为异常的原因。

Neurochemical changes of the monoaminergic neurones in lead-exposed workers

Platelet [3H] 5-HT uptake,lymphocyte dopamine receptors and urinary HVA concentration were measured in 70 workers with mild to moderate increase in blood-lead levels.A marked decrease in lymphocyte [3H] spiroperidol specific binding sites and a significant increase in urinary levels of the dopamine metabolite homovanillic acid(HVA)have been observed in the lead-exposed workers.If such a correlation really exists between lymphocytes and brain striatal DA receptors,our data will favor the role of presynaptic alterations in the mechanisms of the lead neurotoxicity.On the other hand,we observedthat the active uptake rate for [3H] 5-HT in platelets of the lead-exposed workers was significantly inhibited compared with that of the unexposure to lead indicating the inorganic lead-induced effect on the 5-HT uptake mechanism.The results reinforced the hypothesis that the DA and 5-HT neurons are sensitive to relatively moderate levels(The average blood-lead levels were 3.5-3.9μmol/L)of lead exposure in human.