Verschuuren H G, Kroes R, Den Tonkelaar E M
Toxicology. 1975;3(3):349-59. doi: 10.1016/0300-483x(75)90036-0.
The herbicieds 2-methyl-4-chlorophenoxy acetic acid (MCPA) and 2-(2-methyl-4-chlorophenoxy) propionic acid (MCPP or mecoprop) were tested for 90 days in rats. The compounds were added to the diet at levels of 0, 50, 400, and 3200 ppm. Growth, food intake, mortality, haematology, blood and liver chemistry, organ weights and histopathology were used as criteria. The main effects of both compounds were growth retardation and elevated relative kidney weights at levels of 400 ppm and more. The 50 ppm dose level can be considered as a no-toxic-effect level in the 90-day study. In subacute dermal studies in rabbits during 3 weeks the dosages were 0, 0.5, 1.0 and 2 g MCPA or MCPP per kg body weight. Therafter followed a recovery period of 2 weeks. Growth, mortality, skin reaction, haematology, organ weights (MCPP) and histopathology were recorded and determined. Both compounds caused slight to moderate erythema at all dose levels, whereas elasticity of the skin was decreased. In both experiments the skin returned to normal during the recovery period. Weight loss was observed at all dose levels. In the MCPA experiment high mortality and histopathological changes in the liver, kidneys, spleen and thymus were recorded at the two highest dose levels. The cause of this could have been either the treatment with MCPA or a dysbacteria infection which developed during the experiment. Oral and intraperitoneal acute toxicity of MCPP for the rat were found to be 1210 and 402 mg/kg, respectively. After a single oral or dermal application of MCPA to the rabbit, the compound was excreted unchanged in the urine.
除草剂2-甲基-4-氯苯氧基乙酸（MCPA）和2-（2-甲基-4-氯苯氧基）丙酸（MCPP或甲羧除草醚）在大鼠中进行了90天的试验。这些化合物以0、50、400和3200 ppm的水平添加到饮食中。生长、食物摄入量、死亡率、血液学、血液和肝脏生化指标、器官重量和组织病理学被用作评判标准。两种化合物的主要影响是在400 ppm及以上水平时生长迟缓以及相对肾脏重量增加。在90天的研究中，50 ppm的剂量水平可被视为无毒性作用水平。在兔子的亚急性皮肤试验中，为期3周的剂量分别为每千克体重0、0.5、1.0和2克MCPA或MCPP。之后有2周的恢复期。记录并测定生长、死亡率、皮肤反应、血液学、器官重量（MCPP）和组织病理学。两种化合物在所有剂量水平下均引起轻微至中度红斑，而皮肤弹性下降。在两个实验中，皮肤在恢复期均恢复正常。在所有剂量水平下均观察到体重减轻。在MCPA实验中，在两个最高剂量水平记录到肝脏、肾脏、脾脏和胸腺的高死亡率和组织病理学变化。其原因可能是MCPA处理，也可能是实验期间发生的菌群失调感染。发现MCPP对大鼠的口服和腹腔急性毒性分别为1210和402毫克/千克。给兔子单次口服或经皮施用MCPA后，该化合物在尿液中未发生变化地排出。
