Study On Antibiosis, Growth Promotion Effect And Pharmacokinetics Of Quinocetone In Common Carp(Cyprinus Carpio Linnaeus) And Channel Catfish(Ictalurus Punctatus)

In this paper, The vitro antibacterial activity of quinocetone against aquatic pathogenic bacteria was studied; The growth effect of quinocetone in carp(Cyprinus carpio Linnaeus), channel catfish(Ictalurus punctatus) under condition of pond culture was researched; A high performance liquid chromatography method was developed to determine the residues of quinoacetone and metabolin of quinoacetone simultaneously in muscle tissues of fish; The pharmacokinetics and tissue distribution of quinocetone in carp(Cyprinus carpio Linnaeus) and channel catfish(Ictalurus punctatus) was investigated.1.The vitro antibacterial activity of quinocetone and the control drug olaquindox against Aeromonas hydrophila and the other six kinds of aquatic pathogens was studied. The results showed that:Quinocetone against Aeromonas hydrophilia and other two kinds of bacteria's minimal inhibitory concentration (MIC) is the same as olaquindox, is 32mg/L, against Vibrio anguillarum, the antimicrobial effect of quinocetone is better than olaquindox,against dot Aeromonas subspecies (A.punctata subsp.punctata) and other two kinds of bacteria,the bacteriostatic effect of quinocetone is slightly worse than olaquindox.2.Gradient test method was used to study growth-promoting effect of feed adding different quinocetone levels (0,50,75, 100mg/kg) in carp(Cyprinus carpio Linnaeus) and channel catfish(Ictalurus punctatus) under condition of pond culture,and the breeding period was 60d. The results showed that:Compared with the control group, all dosing groups in faster growth and lower mortality rates, feed conversion rates declined; when the additive amount of 75mg/kg feed, the effect was the most obvious, growth rates of carp(Cyprinus carpio Linnaeus), channel catfish(Ictalurus punctatus) were significantly higher than the control group (P<0.05), feed conversion rate was significantly lower than the control group (P<0.05), survival rate was significantly higher (P<0.05).3. A high performance liquid chromatographic method was developed to determine simultaneously the residues of quinoacetone and metabolin of quinoacetone in muscle tissues of Ictalurus punctatus, Cyprinus carpio Linnaeus and Ctenopharyngodon idellus samples.The samples were extracted with acetonitrile. The extracts were defatted with hexane,concentrated by rotary evaporation, then dried under nitrogen gas at 50℃and redissolved with mobile phase. The target compounds were detected by Waters 515 liquid chromatography with detection wavelength of 320 nm and flow rate of 1.0mL/min. The quantitation analysis was performed with external standard method. The result indicated that the standard curves were linear in the ranges of 0.08～2.50mg/L for quinocetone with a correlation coefficient r was 0.9997, and 0.02～0.50mg/mL for desoxyquinocetone with a correlation coefficient of 0.9997.The recoveries of quinocetone were 75.4%～83.4% at spiked levels of 40.0～300μg/kg and the detection limit was 3.48～7.35μg/kg. The recoveries of desoxyquinocetone were 74.5%～82.7% at spiked levels of 40.0-300μg/kg and the detection limit was 5.67～16.23μg/kg.4. In order to study the pharmacokinetics and tissue distribution of quinocetone in carp and channel catfish, quinocetone has been investigated by determining its concentration in plasma and tissues of carp and channel catfish at 15±1℃water temperature. The results indicated that both of the concentration-time course of quinocetone in the plasma of carp and channel catfish can be described as a two-compartmental open model, model equation were C=0.5012e-0.4342t +0.4876e-0.0193t -0.9888e-0.0193t, C=1.4970e-0.1451t +36.3033e-0.0222t-37.8003e-0.0222t respectively.The concentration of quinocetone in the plasma of carp amounted to the largest(0.436μg/mL) at 5h,and in liver,kidney,muscle at 8h,16h,16h respectively, concentrations were 71.832μg/g,22.307μg/g and 0.675μg/g respectively,the main pharmacokinetic parameters (T1/2(ka)),(T1/2β),AUC were 1.263h,35.866h,24.585(μg.ml-1).h respectively;the concentration of quinocetone in the plasma of channel catfish which amounted to the largest(22.097μg/mL) at 15h and in liver,kidney,muscle at 16 h,48 h,72 h respectively, concentrations were 0.852μg/g,1.324μg/g and 0.262μg/g respectively,the main pharmacokinetic parameters (T1/2(ka)),(T1/2β),AUC were 4.669h,31.164h,1387.915 (μg.ml-1).h respectively. The results showed that quinocetone was distributed quickly in both kinds of fish,which mainly metabolized by liver and kidney. Quinocetone was absorbed more quickly in carp than in channel catfish.Compared with pigs and chickens, the absorption rate and elimination rate of quinocetone in carp and channel catfish were slower.