| This study tested the influence factors on bioavailability of acetylisovaleryltylosin tartrate in chicken primary hepatocytes cells,Caco-2 cells and intestinal;determined the effect of acetylisovaleryltylosin tartrate on CYP1A,CYP3A and P-gp in both cell lines and intestinal;investigated the effect of CYP1A,CYP3A and P-gp on bioavailability of acetylisovaleryltylosin tartrate in broiler chicken.The details are divided into eight parts as follows:1 The study on bioavailability of acetylisovaleryltylosin tartrateIn order to study on oral bioavailability of acetylisovaleryltylosin tartrate,the processing method and HPLC(HPLC)detection method of acetylisovaleryltylosin was established in the plasma,medium and buffers.AA broilers a day of age were fed diet without any drugs to 28 days and selected 20 healthy male broilers into the oral group and intravenous group with 10 per group.One group were fed 10 mg·kg-1.b.w of acetyl-isovaleryltylosin tartrate solution,while the other one was intravenous.Given acetyl-isovaleryltylosin tartrate within 24 h,all broilers were bleeding collection from the wing vein,and then plasma concentration was measured by HPLC and concentrations-time date was analyzed by 3P97.The results showed,HPLC method was fit for the requirements of quantitative detection.The pharmacokinetics process of single dose oral and intravenousr acetylisovaleryltylosin tartrate on the broiles consistents with the two-compartment open model.The area under the plasma concentration-time curve(AUC)of acetylisovaleryl tylosin after oral administration was 0.82 ?g·mL-1·h,time to peak concentration(Tmax)was 0.72 h;while area under the plasma concentration-time curve(AUC)was 6.47?g·mL-1·h after intravenous acetylisovaleryltylosin.It suggested that acetylisovaleryl tylosin tartrate is absorbed rapidly after oral administration,but the oral bioavailability(F)is only 12.67%.2 Located and quantitative research of affected area of acetylisovaleryltylosin tartrate oral bioavailabilityAA broilers a day of age were fed to 42 days,and then 40 healthy male broilers were selected randomly to divide into oral administration group,duodenal administration group,portal vein administration group and vein administration group with 10 per group.After beinganesthetized,all broilers were given acetylisovaleryltylosin tartrate solution with 10 mg·kg-1 dose by the above administration.Given acetylisovaleryltylosin tartrate within 24 h,all broilers were bleeding collection from the wing vein,and then plasma concentration was measured by HPLC and the concentrations-time data was analyzed by 3P97.The results showed that after all broilers were given drug with a single dose by different routes of administration,the pharmacokinetics progress of acetylisovaleryltylosin consistents with the two-compartment open model.Area under the plasma concentration-time curves(AUC)of the portal vein administration group and intravenous administration group were higher significantly than that of the oral administration group,the area under the plasma concentration-time curve(AUC)of intravenous administration group was significantly higher than the portal administration group.It suggested that the oral bioavailability of acetylisovaleryltylosin tartrate is about 10%with the influence of intestinal and liver mainly.The intestinal is amounted to 87.2%,followed by the liver is16.2%.3 Study on metabolism and elimination and absorption and transport of acetyl isovaleryltylosin tartrate in vitroThe use of chicken primary hepatocytes cells metabolism model in vitro?Caco-2 cell monolayers transport model in vitro and intestinal perfusion model,to study the metabolism eliminate and transport absorption in vitro of acetylisovaleryltylosin tartrate respectively.In chicken primary hepatocytes primary cells metabolism model in vitro,metabolism eliminate characteristics was examined by adding acetylisovaleryltylosin tartrate concentration,while the metabolism influence of CYP1A and CYP3A on acetylisovaleryl tylosin tartrate was examined by inhibiting the CYP1A and CYP3A activity.In Caco-2 monolayers cells transport model in vitro,absorption characteristics was examined by adding acetylisovaleryltylosin tartrate concentration and EGTA,and the transport influence of P-gp was investigated by inhibiting P-gp.In intestinal perfusion model,duodenum?jejunum and ileum were unidirectional perfusion respectively by adding EGTA and inhibiting P-gp for studying the major absorption bowel of acetylisovaleryl-tylosin tartrate and the transport influence of P-gp.The results showed that acetylisovaleryltylosin tartrate had metabolism elimination with a concentration-dependent manner and consistents with the enzymatic kinetics.After CYP3A was inhibited,its metabolism elimination has a reduction significantly.Paracellular transport and transport across cell were coexistence in Caco-2 cells.Transfer coefficient could increase with EGTA's presence,and existed efflux phenomenon of P-gp mediated.In the process of perfusion in the small intestine,the duodenum absorbed rapidly with transcellular transport mainly.EGTA was difficult to improve the absorption efficiency;meantime verapamil reduced significantly the efflux of P-gp mediated.The duodenum absorbed well by transport coefficients of the bowel presumably,while the absorptionin the jejunum and ileumis general.It suggested that CYP3A has participated metabolic elimination of acetylisovaleryltylosin tartrate,suggesting that CYP3A can reduce the oral bioavailability with the first-pass effect caused by metabolic elimination.The effect of intestinal is caused by the intestinal malabsorption and metabolic efflux by P-gp mediated and metabolism in the mesentery.4 The effect of CYP3A and P-glycoprotein on pharmacokinetics of acetylisovaleryl tylosin tartrate in broilersAA broilers a day of age were fed to 42 days,and then 60 healthy male broilers were selected to divide into control group,ketoconazole-treated group and verapamil-treated group.AA broilers in Ketoconazole-treated group were fed ketoconazole with 60 mg kg-1.b.w,1 time/day for three days.0.5 h after the last drenching,broilers were treated with acetylisovaleryltylosin tartrate at 10 mg·kg-1.b.w by gavage and intravenous.Verapamil-treated group and the control group have the same operation with ketoconazole treated group,were continuously fed with 9 mg verapamil and the same volume of NS respectively.0.5 h after drenching on the third day,broilers were treated by gavage and intravenous acetylisovaleryltylosin tartrate solution with 10 mg·kg-1.b.w.After administration,all broilers were bleeding collection from the wing vein within 24 h,then plasma concentration was measured by HPLC and the concentrations-time data analyzed by 3P97.The result showed that the pharmacokinetics process of single dose oral and intravenousr acetylisovaleryltylosin tartrate on the broiles corresponded with the two-compartment open model.The area under the plasma concentration-time curve(AUC)of acetylisovaleryl tylosin in the control group and the apparent clearance(CL/F)was 0.96?g·mL-1·h and 15.3 L·kg-1·h-1 respectively.CYP3A activity in the body was specifically inhibited by ketoconazole.The area under the plasma concentration-time curve(AUC)of acetyl-isovaleryl tylosin rose to 1.17 times(1.12 ?g·mL-1·h),the apparent clearance rate was 14.8 L·kg-1·h-1,When P-glycoprotein was inhibited specifically in the broilers body,the area under the plasma concentration-time curve was 1.29?g·mL-1·h,increased significantly.It suggested that the metabolism elimination influence of CYP3A on acetylisovaleryl tylosin tartrate in vivo of broilers is not obvious,while P-gp has influential significantly. |
PDF Full Text Request