Masukawa T, Nakanishi K
Department of Clinical Biochemistry, Faculty of Pharmaceutical Sciences, Setsunan University, Osaka, Japan.
Jpn J Pharmacol. 1997 Feb;73(2):175-7. doi: 10.1254/jjp.73.175.
Susceptibility to enoxacin (80 mg/kg, p.o.)-induced convulsions was examined in mice coadministered with fenbufen (100 mg/kg, p.o.) over 24 hr at 3-hr intervals (light 7:00-19:00 hr). There was a marked circadian variation in the incidence of clonic and tonic convulsions and mortality. The susceptibility to enoxacin was higher around 15:00-18:00 hr and lower around 3:00-9:00 hr; the 50% clonic convulsive dose (CD50) at 9:00 and 15:00 hr was 95.0 and 56.5 mg/kg, respectively, its ratio being 1.64. Under these conditions, brain enoxacin level at 15:00 hr was increased 2.43-fold over that at 9:00 hr 30 min after enoxacin administration. Thus, the change of brain enoxacin may contribute to one of the causes of the above circadian variation.
在以3小时的间隔（光照时间为7:00 - 19:00时）连续24小时口服给予小鼠联苯乙酸（100 mg/kg）的同时，检测小鼠对口服依诺沙星（80 mg/kg）诱发惊厥的敏感性。阵挛性和强直性惊厥的发生率及死亡率存在显著的昼夜变化。小鼠对依诺沙星的敏感性在15:00 - 18:00时左右较高，在3:00 - 9:00时左右较低；9:00时和15:00时的50%阵挛性惊厥剂量（CD50）分别为95.0和56.5 mg/kg，两者比值为1.64。在此条件下，依诺沙星给药30分钟后，15:00时脑内依诺沙星水平比9:00时升高了2.43倍。因此，脑内依诺沙星的变化可能是上述昼夜变化的原因之一。
