Fairbrother T E, Kerr L A, Essig H W
Vet Hum Toxicol. 1987 Aug;29(4):312-5.
Clinical signs, gross and histologic necropsy findings and dose response curves of 4-methylimidazole (4-MI) were determined in young Holstein calves. Three-day-old Holstein bull calves were given an oral dose of 0,25,50,100,200 or 400 mg 4-MI/kg body weight. Acute clinical signs were hypersalivation, mouth chomping, diarrhea, muscle fasciculations, tremors, hyperexcitability, convulsions, coma and death. Death occurred within 3 hr for calves given the highest dose of 400 mg/kg. Two of 3 calves dosed at 200 mg/kg died within 8 and 3/4 hr of dosing. Only 1 of 3 calves showed mild signs at the 100 mg/kg dose level and no effects were observed at the 50 or 25 mg/kg dose level. Signs due to 4-MI in this experiment were similar to signs observed in calves whose dams were consuming ammoniated hay. No pathological lesions attributable to 4-MI toxicosis were found during gross or microscopic necropsy examination. Blood chemistry values from calves treated with 4-MI were within normal ranges except for potassium, phosphorus and glucose which were elevated (P less than .05) at the time of death for those calves dosed at 400 mg/kg.
在年轻的荷斯坦犊牛中测定了4-甲基咪唑（4-MI）的临床体征、大体和组织学尸检结果以及剂量反应曲线。给3日龄的荷斯坦公牛犊口服0、25、50、100、200或400毫克4-MI/千克体重的剂量。急性临床体征为流涎过多、咀嚼、腹泻、肌肉束颤、震颤、过度兴奋、惊厥、昏迷和死亡。给予最高剂量400毫克/千克的犊牛在3小时内死亡。3头给予200毫克/千克剂量的犊牛中有2头在给药后8又3/4小时内死亡。在100毫克/千克剂量水平下，3头犊牛中只有1头表现出轻微体征，在50或25毫克/千克剂量水平下未观察到任何影响。本实验中4-MI引起的体征与母畜食用氨化干草的犊牛中观察到的体征相似。在大体或显微镜尸检检查中未发现归因于4-MI中毒的病理病变。除了钾、磷和葡萄糖外，4-MI处理的犊牛的血液化学值在正常范围内，对于给予400毫克/千克剂量的犊牛，在死亡时这些指标升高（P小于0.05）。
