[The experimental study of diquat on the half-Lethal dose and pothological injuny of related organs in wistor rats].

Objective: To explore the acute toxicity of Diquat in mice and to calculate the median lethal dose (LD(50)) of Diquat to rats and observe the pathological changes of tissues and organs in rats with different concentrations of Diquat. Methods: Diquat solution of 50 mg/kg was prepared freshly with 1 000 mg of Diquat and dilute the solution with water to a total of 20 ml. A total of 99 healthy adult male Wistar rats were randomly divided into part one, part two and control groups. In the first part, 36 rats were randomly divided into 4 groups: 100 mg/kg group, 200 mg/kg group, 300 mg/kg group and 400 mg/kg group, which were treated with 100 mg/kg, 200 mg/kg, 300 mg/kg and 400 mg/kg of Diquat solution by gavage, respectively. The death and symptoms of poisoning after intragastric administration were recorded, and the maximum tolerated dose and absolute lethal dose were measured. In the second part, 54 rats were randomly divided into 6 groups: 200 mg/kg group, 220 mg/kg group, 240 mg/kg group, 260 mg/kg、280 mg/kg group and 300 mg/kg group, whichwere treated with 200 mg/kg, 220 mg/kg, 240 mg/kg, 260 mg/kg, 280 mg/kg and 300 mg/kg of Diquat solution by gavage, respectively. The survival of rats in different concentration of Diquat was observed and the LD(50) was calculated by Excel processing the formula of Koch's method. The control group were given equal volume water under the same experimental conditions. And moreover, the lungs, kidneys, hearts, livers, and brain tissues were collected and fixed by formaldehyde, embedded by paraffin, and sectioned for histopathological light microscopy. Results: The maximum tolerated dose was 240 mg/kg and the absolute lethal dose was 300 mg/kg. The LD(50) of Diquat for Rats was 280.58 mg/kg. The high-dose group had significantly more organ damage than the low-dose group after diquat poisoning. Conclusion: The determination of the half-lethal dose of diquat, at the same time observed multiple organs damaged in rats after the diquat quickly poisoned. Kidneys, lungs and heart might be the main organ which was heavily damaged. With the extension of observation time, the organ damage of rats exposed to small doses gradually stabilized.目的： 探讨敌草快对大鼠的急性毒性，明确其对大鼠的半数致死量（LD(50)），观察不同浓度敌草快溶液染毒大鼠组织器官病理损伤变化。 方法： 取敌草快纯品1 000 mg，注射用水溶解稀释至20 ml，配成50 mg/ml溶液。将99只成年健康雄性Wistar大鼠随机分为实验1部分、实验2部分及空白对照组部分。实验1部分共36只大鼠，每组9只随机分为4个染毒组：100、200、300和400 mg/kg组，实验开始一次性分别给予100、200、300和400 mg/kg敌草快溶液，加注射用水稀释至3 ml灌胃。记录大鼠灌胃后死亡和中毒症状，测得最大耐受量和绝对致死量。实验2部分共54只大鼠，每组9只随机分为6个染毒组：200、220、240、260、280和300 mg/kg组，实验开始一次性分别给予200、220、240、260、280和300 mg/kg敌草快溶液，加注射用水稀释至3 ml灌胃。观察不同敌草快浓度时大鼠的存活情况。应用Excel软件利用寇氏法计算公式，计算半数致死量（LD(50)）。空白对照组在相同实验条件下给予等剂量注射用水灌胃。所有动物于实验结束后均留取部分肺脏、肾脏、心脏、肝脏、脑组织，甲醛固定，石蜡包埋，组织切片，行组织病理光镜观察。 结果： 对大鼠敌草快最大耐受量为240 mg/kg，绝对致死量为300 mg/kg，半数致死量为280.58 mg/kg，敌草快染毒后，高剂量组（300、400 mg/kg组）与低剂量组比较，脏器损伤明显，肺脏以炎性细胞浸润为主，肺泡间隔增厚，纤维条索形成很少；肾脏肾小管、肾小球水肿，肾小球毛细血管扩张，内皮细胞肿胀；心肌细胞肿胀，纤维间炎性细胞浸润；肝脏血管周围炎性细胞浸润，中央静脉扩张，肝细胞肿胀，结构紊乱；脑组织灶状炎性细胞浸润。 结论： 敌草快染毒大鼠全身多个脏器受损，主要受损器官为肾脏、肺脏和心脏。随着观察时间延长，小剂量染毒大鼠脏器损伤逐渐稳定。.