Kabuto M
Department of Environmental Health, Japan National Institute of Environmental Studies, Ibasaki.
Arch Toxicol. 1991;65(2):164-7. doi: 10.1007/BF02034946.
Five male Wistar rats were treated with methylmercury chloride (MMC) and compared with five age-matched control rats. A dose of 10 mg/kg was given three times. The chronic effects of the MMC administration on the urinary output of catecholamines [norepinephrine (NE), epinephrine (E) and dopamine (DA)] were measured for 50 days. On the 69th day after MMC administration, the rats were examined for insulin-induced hypoglycemic stress. On the 90th day, the animals were decapitated and various organs were weighed and serum thyroid hormones [thyroid stimulating hormone (TSH) and total and free thyroxine (T4)] were measured. Decreases in DA excretion and DA response to stress were observed in the MMC-treated group. Inflammation of the kidney was also found, suggesting MMC-induced damage to the renal tubular region, the apparent site of renal DA synthesis. The MMC group and the control group showed differential NE and E response patterns. The lowered baseline excretion of NE appeared to continue even 70 days after MMC administration, while the difference in E excretion between the two groups disappeared 1 month after MMC administration. Both NE and E showed normal responsiveness to hypoglycemic stress induced by insulin. All serum TSH and total and free T4 baseline levels showed slight increases, and the thyroid gland weights in the MMC group were slightly heavier. These findings suggest a rather hyperthyroid state after the initial acute phase suppression, as suggested by the previous examinations. Thus, these findings suggest long-lasting effects of methylmercury administration, especially on renal DA synthesis. Baseline urinary excretion of NE and thyroid function could also be affected for a long time.
五只雄性Wistar大鼠接受氯化甲基汞（MMC）处理，并与五只年龄匹配的对照大鼠进行比较。以10mg/kg的剂量给药三次。在50天内测量MMC给药对儿茶酚胺[去甲肾上腺素（NE）、肾上腺素（E）和多巴胺（DA）]尿量的慢性影响。在MMC给药后第69天，检查大鼠对胰岛素诱导的低血糖应激反应。在第90天，将动物断头，称量各种器官重量，并测量血清甲状腺激素[促甲状腺激素（TSH）以及总甲状腺素和游离甲状腺素（T4）]。在MMC处理组中观察到DA排泄减少以及DA对应激的反应降低。还发现了肾脏炎症，提示MMC对肾小管区域造成损伤，而肾小管区域是肾脏DA合成的明显部位。MMC组和对照组表现出不同的NE和E反应模式。NE的基础排泄降低似乎在MMC给药后70天仍持续存在，而两组之间E排泄的差异在MMC给药后1个月消失。NE和E对胰岛素诱导的低血糖应激均表现出正常反应性。所有血清TSH以及总T4和游离T4的基础水平均略有升高，MMC组的甲状腺重量略重。这些发现表明，如先前检查所示，在初始急性期抑制后存在相当程度的甲状腺功能亢进状态。因此，这些发现提示甲基汞给药具有长期影响，尤其是对肾脏DA合成。NE的基础尿排泄和甲状腺功能也可能在很长一段时间内受到影响。
