大剂量三聚氰胺急性染毒大鼠泌尿系统损伤研究

Acute toxicity study on the damage of urinary system in the rats administered the large-dose melamine

目的探讨大剂量(3 000 mg/kg)三聚氰胺急性染毒24 h后大鼠泌尿系统损伤情况。方法将清洁级雄性Wistar大鼠随机分为3组,分别为空白对照组、溶剂对照组(1%羧甲基纤维素钠溶液)和实验组(三聚氰胺染毒剂量3 000mg/kg),每组10只。单次经口染毒,观察24 h。24 h后处死动物,取血清检测尿素氮、肌酐和尿酸,称量心、肝、脾、肾、膀胱并计算脏器系数,对心、肝、脾、肾、输尿管和膀胱进行病理学观察。结果大剂量三聚氰胺染毒24 h后,实验组大鼠出现血尿、少动、眼睑下垂、体重下降,无死亡;尿素氮、肌酐、尿酸值和肾脏器系数均高于空白对照组和溶剂对照组(P<0.05),肝、脾脏器系数低于两对照组(P<0.05)。肉眼观察实验组大鼠肾表面出现灰白色斑,膀胱充血,在输尿管和膀胱中有结晶样物质形成;显微镜下见输尿管和膀胱组织出现局部黏膜缺损和红细胞渗出。结论大剂量三聚氰胺染毒24 h后即可在泌尿系统形成结晶样物质,泌尿系统功能损伤严重。

Objective To explore the damage of urinary system in the rats exposed to melamine（3 000mg/kg） after 24 h.Methods Thirty clean male Wistar rats were randomized into three groups,10 in each,administered water（blank control group）,1% sodium carboxymethylcellulose（solvent control group） and 3 000 mg /kg melamine（experimental group）,respectively.After a single oral exposure of melamine,rats were observed the behavioral state during 24 h.After 24 h the animals were killed and detecting the serum levels of blood urea nitrogen,creatinine and uric acid,weighing the heart,liver,spleen,kidney and bladder,calculating the organ coefficient,and examining heart,liver,spleen,kidney,ureter and bladder for pathological.Results 24 h exposure to large-doses melamine,the experimental group was observed hematuria,lack of exercise,ptosis,weight loss and no death.And blood urea nitrogen,creatinine,uric acid levels and kidney coefficient were higher than the blank control group and solvent control group（P 0.05）,and both liver and spleen coefficient were lower than the control group（P〈 0.05）.In the experimental group,naked eye gray spots in renal surface and bladder congestion,and in the ureter and bladder found some crystals;microscopic examination showed local mucosal defect and red blood cell leakage of the urethra and bladder tissue.Conclusion After 24h exposure to large-doses melamine can form crystals in the urinary system,and cause severe urinary dysfunction.