Cambar J, Cal J C, Desmouliere A, Guillemain J
C R Seances Acad Sci III. 1983;296(20):949-52.
If circadian variations in tolerance to drugs have been often demonstrated, such observations about heavy metals are still very scarce. The present study proposes to determine if circadian variations occur in the tolerance of Mice to single lethal dose of cadmium sulphate. 400 female mice, kept in cages on a 8.00-20.00 L/D cycle, received IP a single cadmium sulphate injection at different doses (2.5, 3, 3.5 and 4 mg/kg) at different hours in the day (8.00, 14.00, 20.00 and 2.00 hrs.). Death number was determined each day during 10 consecutive days. The mortality percentage is a function of the time of the cadmium administration, varying between 3.3 and 21.7% for 2.5 mg/kg, between 16.7 and 43.3% for 3 mg/kg, between 33.3 and 71.7% for 3.5 mg/kg and between 73.3 and 96.7% for 4 mg/kg. The metal is the most toxic at 20.00 hr (mean: 58.3%) and the least at 2.00 hr. (mean: 33.7%). A circadian susceptibility to cadmium sulphate in Mice thus clearly appears, as has been recently described with mercury and platinum.
如果药物耐受性的昼夜变化已被多次证实，那么关于重金属的此类观察结果仍然非常稀少。本研究旨在确定小鼠对单次致死剂量硫酸镉的耐受性是否存在昼夜变化。400只雌性小鼠饲养在笼子里，光照/黑暗周期为8:00 - 20:00，在一天中的不同时间（8:00、14:00、20:00和2:00时）腹腔注射不同剂量（2.5、3、3.5和4毫克/千克）的单次硫酸镉。连续10天每天记录死亡数量。死亡率是镉给药时间的函数，2.5毫克/千克时在3.3%至21.7%之间，3毫克/千克时在16.7%至43.3%之间，3.5毫克/千克时在33.3%至71.7%之间，4毫克/千克时在73.3%至96.7%之间。该金属在20:00时毒性最大（平均：58.3%），在2:00时毒性最小（平均：33.7%）。因此，小鼠对硫酸镉的昼夜易感性明显显现，正如最近对汞和铂的描述一样。
