Chin K, Ryu J H, Cheong J H, Ko K H, Kuroiwa Y
National Institute of Safety Research, Seoul National University, Korea.
J Toxicol Sci. 1992 Nov;17(4):197-210. doi: 10.2131/jts.17.197.
Alterations of tyrosine hydroxylase activity in various regions of brain from rats postnatally exposed to lead were tested. Three groups of animals were prepared; (1) Rats exposed to lead at a low dose (0.05% lead acetate, 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 brain and body, and concentrations of lead in whole brain of animals in each group were measured. Activities of tyrosine hydroxylase and Na(+)-K+ ATPase were also measured at the same ages in 4 brain regions of each animal. Body weight gain was decreased after 6 weeks of age in rats exposed to lead at a high dose. Concentrations of lead in whole brain were increased from 0.37 to 0.83 (ng/mg wet tissue) in these animals. Exposure of rats to lead generally increased tyrosine hydroxylase activity and decreased Na(+)-K+ ATPase activity. However, changes of tyrosine hydroxylase activity were detected without concomitant changes of Na(+)-K+ ATPase activity in pons-medulla at 2 weeks of age and telencephalon at 6 weeks of age in rats exposed to lead at a low dose, and in midbrain at 4 and 6 weeks of age in rats exposed to lead at a high dose. These data imply that catecholaminergic nervous system in the brain regions described above could be selectively affected by lead.
对出生后接触铅的大鼠大脑不同区域酪氨酸羟化酶活性的改变进行了检测。制备了三组动物：(1) 低剂量接触铅的大鼠 (0.05% 醋酸铅，PbAc)；(2) 高剂量接触铅的大鼠 (0.2% PbAc)；(3) 年龄匹配的正常对照大鼠。在2、4、6和8周龄时，测量每组动物的脑重和体重以及全脑铅浓度。还在相同年龄测量每组动物4个脑区的酪氨酸羟化酶和Na(+)-K+ ATP酶活性。高剂量接触铅的大鼠在6周龄后体重增加减少。这些动物全脑铅浓度从0.37增加到0.83（纳克/毫克湿组织）。大鼠接触铅通常会增加酪氨酸羟化酶活性并降低Na(+)-K+ ATP酶活性。然而，在低剂量接触铅的大鼠2周龄时脑桥-延髓和6周龄时端脑以及高剂量接触铅的大鼠4和6周龄时中脑，检测到酪氨酸羟化酶活性的变化而无Na(+)-K+ ATP酶活性的伴随变化。这些数据表明上述脑区的儿茶酚胺能神经系统可能受到铅的选择性影响。
