Lee J H, Han D H
Department of Industrial Health, College of Health Sciences, Inje University, Kimhae, Kyongnam-do, Republic of Korea.
J Toxicol Environ Health. 1995 Aug;45(4):415-25. doi: 10.1080/15287399509532005.
Various doses of methylmercuric chloride (MMC) were administered orally to pregnant Fischer 344 rats on d 7 of gestation. On d 20 of gestation the dams were laparotomized under ether anesthesia, and the fetuses were removed. Maternal body weights were decreased for 2 d and 6 d in rats given 10 and 20 mg/kg MMC, and were continuously decreased for those given 30 mg/kg MMC. Maternal weight gain of each group was decreased to 86.2%, 78.9%, and 61.9% of control group on d 20 of gestation. The reduction of litter weight was greatly enhanced with increasing MMC doses, presumably due to postimplantation loss, which was already increased at high treatment levels. The LD50 of MMC for fetuses was determined to be 16.5 mg/kg. Mercury content in maternal organs was highest in kidney, followed by blood, spleen, liver, and brain, while in fetal organs it was highest in liver. Fetal liver and brain contained more mercury than maternal liver and brain. However, fetal kidney retained less mercury than maternal kidney. Fetal ossification center was not completely formed in sternebrae, particularly in fifth and second bones, pelvic bones, and pectoral phalanges of fetuses in rats treated with 30 mg/kg MMC. The ossified lengths of skeletal bone stained with alizarin red S were developed least in fifth sternebrae, metacarpals in the pectoral girdle, and ischium in the pelvic girdle, and were severely retarded in development as position of the ribs goes from the sixth bone (center) to the first and 13th bone (each edge). These results indicate that MMC is embryotoxic in Fischer 344 rats.
在妊娠第7天，给怀孕的Fischer 344大鼠经口给予不同剂量的甲基氯化汞（MMC）。在妊娠第20天，将母鼠在乙醚麻醉下进行剖腹手术，并取出胎儿。给予10和20 mg/kg MMC的大鼠母体体重在2天和6天时下降，而给予30 mg/kg MMC的大鼠母体体重持续下降。在妊娠第20天，每组母体体重增加量降至对照组的86.2%、78.9%和61.9%。随着MMC剂量增加，窝仔体重的减少显著增强，这可能是由于着床后损失增加，在高剂量处理水平下这种损失已经增加。MMC对胎儿的半数致死剂量（LD50）测定为16.5 mg/kg。母体器官中的汞含量在肾脏中最高，其次是血液、脾脏、肝脏和大脑，而在胎儿器官中，肝脏中的汞含量最高。胎儿肝脏和大脑中的汞含量高于母体肝脏和大脑。然而，胎儿肾脏中的汞含量低于母体肾脏。在用30 mg/kg MMC处理的大鼠胎儿中，胸骨，特别是第五和第二块骨头、骨盆骨和胸指骨的胎儿骨化中心未完全形成。用茜素红S染色的骨骼骨化长度在第五胸骨、胸带中的掌骨和骨盆带中的坐骨中发育最少，并且随着肋骨位置从第六块骨头（中心）到第一和第十三块骨头（每个边缘），发育严重受阻。这些结果表明，MMC对Fischer 344大鼠具有胚胎毒性。
