Study Of The Effects Of Enrofloxacin On Mice Hepatic CYP450

Cytochrome P450(CYP450) is the most important enzymes in the microsomal mixed function oxidase, which involved in many endogenous and exogemous compounds’ biotransformation in vivo. CYP450has important significance to maintain the body’s homeostasis, to study the metabolic between the drugs and to guide rational use the clinical drugs. CYP450has extremely wide metabolic substrates and plays an important role in the metabolic of drugs. As the same time, many drugs could also inhibit or induce the CYP450, which could affect the metabolic of other drugs in vivo. So it is very necessary to research the drug metabolic effect of the CYP450. It will help us to reveal the drug interaction in vivo and to guide reasonable application the clinical drugs.To study the effects of enrofloxacin (EF) on the mice hepatic CYP450s and EF combined with CTX, RFP, PB on the mice hepatic CYP450s in vitro and vivo. EF single use test:in vivo test, the experimental mouse were intraperitoneal injected EF (mg·kg-1):5(low dose group)、25(middle dose group) and125(high dose group), continuously for5days; in vitro test, the different concentration of EF (mmol·l-1):5(low dose group)、25(middle dose group) and125(high dose group), were added to the mice hepatic microsome incubation system and incubated at37℃for1h. EF drug combination test:in vivo test, the mouse were randomly divided into four groups and respectively intraperitoneal injection of25mg·kg-1EF, then were respectively given SPSS、25mg·kg-1CTX、10mg·kg-1RFP、40mg·kg-1PB continuously for5days; in vitro test,25mmol·l-1EF was first mixed to the mice hepatic microsome incubation system, then SPSS、20mmol·l-1CTX、10mmol·l-1RFP、30mmol·l-1PB were respectively added in the system and incubated at37℃for1h.The mouse liver microsome was extracted by low temperature differential centrifugation. The contents of CYP450and b5were detected by CO reducing differential spectroscopy and b5scanning spectra. The activities of CYP1A2、CYP2B6、CYP2C9、CYP2E1and CYP3A4were detected by fluorescence method. The expression of mice CYP450s’(CYP1A2、CYP2B6、CYP2C9、CYP2E1and CYP3A4) protein was detected by Western-Blot.Both in vivo and vitro, the result of EF single use test showed:compared with control group, low dose EF had no effect on the content of mice hepatic microsomal P450and b5(P＞0.05), middle and high dose EF had significant inhibition effect on the content of mice hepatic microsomal P450and b5(P＜0.01). Compared with control group, low、middle and high dose EF had significant inhibition effect on the activities of mice CYP1A2、CYP3A4、 CYP2C9(P＜0.05); low dose EF had significant inhibition effect on the activities of mice CYP2E1(P＜0.05), middle and high dose EF had extremely significant induced effect on the activities of mice CYP2E1(P＜0.01); middle dose EF had extremely significant induced effect on activity of CYP2B6(P＜0.01). Compared with control group, low、high and middle dose EF had extremely significant inhibition effect on the protein of CYP1A2、 CYP2C9、CYP2E1、CYP3A4(P＜0.01); middle and high dose EF had extremely significant induced effect on the protein of CYP2E1(P＜0.01); middle dose EF had extremely significant induced effect on the protein of CYP2B6(P＜0.01). Consolution:both in vivo and vitro, EF had affected on the content of mice micromomal protein、CYP450and b5、 activities and expression of protein on CYP1A2、CYP2B6、CYP2C9、CYP2E1、CYP3A4. This affection showed inhibition or induced. This affection was intently related to the dose of EF and kind of enzyme.Both in vivo and vitro, the result of EF drug combination test showed:compared with EF group, EF+CTX、EF+RFP group had no significant effect on the content of mice hepatic microsomal P450and b5(P＞0.05), EF+PB group had significant induced effect on the content of mice hepatic microsomal P450and b5(P＜0.05).Compared with EF group, EF+CTX group had extremely significant inhibition effect on CYP1A2、CYP3A4activities (P＜0.01), while had extremely significant or significant induced effect on CYP2B6、 CYP2E1activities (P＜0.05), and had no effect on the activity of CYP2C9(P＞0.05); EF+RFP group had extremely significant induced effect on CYP1A2、CYP2B6、CYP2C9、 CYP3A4activities (P＜0.01), while had no effect on the activity of CYP2E1(P＞0.05); EF+PB group had extremely significant induced effect on the activities of CYP1A2、 CYP2B6、CYP2C9、CYP2E1、CYP3A4(P＜0.01). Compared with EF group, EF+CTX group had no effect on the protein of CYP1A2、CYP2C9(P>0.05), while had significant inhibition effect on the protein of CYP3A4(P＜0.01) and had significant induced effect on the protein of CYP2B6、CYP2E1(P＜0.01); EF+RFP group had extremely significant induced effect on the protein of CYP1A2、CYP2C9、CYP2E1、CYP3A4(P＜0.01);EF+PB group had extremely significant induced effect on the protein of CYP1A2、CYP2B6、 CYP2C9、CYP2E1、CYP3A4(P＜0.01). Consolution:both in vivo and vitro, EF+CTX group had affected on the mice micromomal activities and expressions of protein on CYP1A2、CYP2B6、CYP2C9、CYP2E1、CYP3A4. This affection showed inhibition. EF+RFP、EF+PB group had affected on the mice micromomal activities and expressions of protein on CYP1A2、CYP2B6、CYP2C9、CYP2E1、CYP3A4. This affection showed induced.