氟喹诺酮类药物对大鼠肝微粒体细胞色素P450酶系的影响

Effects of quinolones on liver microsome cytochrome P450 in rats

目的比较4种氟喹诺酮类药物[左氧氟沙星(LVFX)、加替沙星(GTFX)、莫西沙星(MXFX)、帕珠沙星(PZFX)]对大鼠肝微粒体细胞色素P450(CYP450)酶系的影响。方法 30只雄性Wistar大鼠随机分为空白对照组、LVFX组(LV组)、GTFX组(GT组)、MXFX组(MX组)、PZFX组(PZ组),每组6只,给药方案为120mg/(kg.d),尾静脉注射给药,连续7d。末次给药后24h处死动物,差速离心法制备肝微粒体混悬液,Lowry法测定肝微粒体蛋白浓度,分光光度法检测肝微粒体CYP450酶系的含量及活性,并采用单因素方差分析进行统计。结果与空白对照组比较,MX组和GT组大鼠肝重明显降低(P<0.01,P<0.05),LV组、GT组和MX组大鼠肝微粒体蛋白浓度明显增加(P<0.01),LV组和GT组CYP450含量增加(P<0.05,P<0.01),GT组细胞色素b5(Cytb5)含量增加(P<0.05)。肝微粒体NADPH-CytC还原酶活性测定结果显示,给药组与空白对照组差异无统计学意义(P>0.05)。氨基吡啉-N-脱甲基酶活性测定结果显示,LV组、GT组和MX组酶活性与空白对照组比较差异均有统计学意义(P<0.01)。红霉素-N-脱甲基酶活性测定结果显示,与空白对照组比较,GT组酶活性降低,MX组酶活性升高,差异有统计学意义(P<0.01)。大鼠肝微粒体CYP450酶系亚家族活性检测结果显示,与空白对照组比较,LV组、MX组和PZ组7-苄基香豆素脱烃酶(BROD)活性升高(P<0.01),GT组7-甲氧基香豆素脱烃酶(MROD)活性降低(P<0.05)、7-苯基香豆素脱烃酶(PROD)活性增加,PZ组PROD活性降低(P<0.01),4种药物均可使乙氧基香豆素脱烃酶(EROD)活性增加(P<0.01)。结论 4种氟喹诺酮类药物对CYP450酶系均有肯定作用,对不同的酶其作用效果不同,从影响范围来看,GTFX、MXFX、LVFX和PZFX的作用依次减小。

Objective To study and compare the effects of fluoroquinolones （levofloxacin, gatifloxacin, moxifloxacin and pazufloxacin） on the enzyme system of liver microsome cytochrome P450 in rat. Methods Thirty male Wistar rats were equally assigned into five groups： control group, levofloxacin （LV） group, gatifloxacin （GT） group, moxifloxacin （MX） group and pazufloxacin （PZ） group. Each drug was consecutively administered by tail vein injection for 7 days in a dosage of 120 mg/（kg.d）. Liver microsomes were prepared by differential centrifugation, the concentration of protein in the liver microsome was measured by Lowry method, the content and activity of cytochrome P450 were detected by spectrophotometric determination, and the results were analyzed by one-way ANOVA. Results Compared with control group, the weight of liver in MX group and GT group was significantly reduced （P〈0.01 or P〈0.05）; microsomal protein content of liver in LV group, GT group and MX group significantly increased （P〈0.01）; the content of CYP450 in LV group and GT group increased （P〈0.05 or P〈0.01）; the content of cytochrome b5 （CytbS） in GT group increased （P〈 0.05）. Assessment of NADPI-I-CytC reductase activity in the liver microsomes showed that there was no statistically significant difference between drug groups and control group （P〉0.05）. Assay of aminopyrine-N-demethylase activity showed that the difference in enzyme activity was statistically significant between the control group and groups LV, GT and MX （P〈0.01）. Erythromycin-N-demethylase activity measurement revealed that the enzyme activity was lowered in GT group and slightly elevated in MX group, and the difference was statistically significant compared with that of control group （P〈0.01）. Measurement of activity of rat liver microsomal CYP450 enzyme system subfamily showed that the BROD activity increased in LV, MX and PZ groups （P〈0.01）, and slightly decreased in GT group as compared with control group （P〈0.05）. The PROD activity increased in GT group, but decreased in PZ group （P〈0.01）. The EROD activity increased in all the four groups （P〈0.01）. Conclusions The four fluoroquinolones have some effects on the enzyme system of liver microsome cytochrome P450 in rats, but the effects may be different （enhancement or attenuation of the enzymatic activity） depending on the enzymes, and the extent of the decrease of effect is in the following order： gatifloxacin, moxifloxacin, levofloxacin and pazufloxacin.