Chin K, Lee C J, Seo K O, Ko K H, Kuroiwa Y
National Institute of Safety Research, Seoul, Korea.
J Toxicol Sci. 1993 Feb;18(1):11-9. doi: 10.2131/jts.18.11.
Selectivity of lead effect to phenylethanolamine N-methyltransferase (PNMT) activity in regions of brain from rats postnatally exposed to lead was tested. Three groups of animals were prepared; (1) Rats exposed to lead at a low dose (0.05% PbAcetate: PbAc); (2) Rats exposed to lead at a high dose (0.2% PbAc); (3) Age-matched normal control rats. At 2, 4, 6 and 8 weeks of age weight of whole brain and body in each group were measured. At the same ages activities of PNMT and Na+/K(+)-ATPase were examined on 4 brain regions of each animal. Exposure of rats to lead generally decreased activity of Na+/K(+)-ATPase and showed alternative change of those of PNMT. Brain regions where changes of PNMT activity were detected without concomitant changes of Na+/K(+)-ATPase activity, were telencephalon and pons/medulla at 2 weeks of age and telencephalon at 4 weeks of age in rats exposed to lead at a low dose, and those in rats exposed to lead at a high dose were pons/medulla at 8 weeks of age. These data imply that adrenergic nervous system in the brain regions described above could selectively be affected by lead.
测试了出生后暴露于铅的大鼠脑区中铅对苯乙醇胺N-甲基转移酶（PNMT）活性影响的选择性。制备了三组动物：（1）低剂量铅暴露组（0.05%醋酸铅：PbAc）；（2）高剂量铅暴露组（0.2%醋酸铅）；（3）年龄匹配的正常对照组大鼠。在2、4、6和8周龄时，测量每组动物的全脑和体重。在相同年龄，检测每组动物4个脑区中PNMT和Na+/K(+)-ATP酶的活性。大鼠暴露于铅通常会降低Na+/K(+)-ATP酶的活性，并使PNMT的活性发生交替变化。在低剂量铅暴露的大鼠中，在2周龄时检测到PNMT活性变化而Na+/K(+)-ATP酶活性无相应变化的脑区是端脑和脑桥/延髓，在4周龄时是端脑；在高剂量铅暴露的大鼠中，在8周龄时是脑桥/延髓。这些数据表明，上述脑区的肾上腺素能神经系统可能会被铅选择性地影响。
