The Toxicity Of Abamectin Effects On Macrobrachium Nipponense And The Pharmacokinetics In MacrobrachiumNipponense

The Yangtze River Delta region is the main culture zones of Macrobrachium nipponense in China, because of breeding pollution, raising technology in recent years,the production of Macrobrachium nipponense fell sharply and couldnot meet the market demands. The fish and shrimp polyculture model can be up to 1 to 2 times per mu. It has been opened a new road. Abamectin drugs (Avermectins AVMs) is a kind of big ring lactone class antibiotic, which produced by retinoids chain through natural fermentation mold. Abamectin drugs are a class of biological pesticides, and have characteristics of chemical novel structure, unique function mechanism, strong insecticidal activity,broad insecticidal spectrum.Abamectin drugs have been widely used in aquaculture, can be used to fish in the fish, shrimp and crab polyculture pond, treated Gyrodactylus ,crab worm and ring worm, lice, etc parasites. Combined with the current breeding condition, we studied the toxicity of abamectin effects on Macrobrachium nipponense and the pharmacokinetics in Macrobrachium nipponense.In order to provide more scientific medicine basis in aquaculture.The toxicity of abamectin on Macrobrachium nipponense has been studied with the method of changing solution for 24 hours to determine the AVM effect on Macrobrachium nipponense, The concentration of 96h LC50 was 0.0533 ug/ml, 95% confidence interval was 0.0495 ~ 0.0573 ug/ml, SC was 0.0053 ug/ml.A reversed phase high performance liquid chromatography method for determination of avermectin in Macrobrachium nipponensis(muscle,hepatopancreas and hemolymph)and water was developed. The samples were drawed by ethl acetdte, evaporated to dryness by nitrogen-blowing at 45℃,daffed with hexane,extracted with C18 reversed-phase chromatography column Hypersil. Mobile phase: methanol-water (86+14), velocity of 1.0mL/min, ultraviolet detector wave length 245nm,sample weight of l0uL chromatographic conditions reversed phase high performance liquid chromatography with ultraviolet detection.The calibration curve of avermectin at the concentration range of 0.005～2μg/mL was linear.The average recovery of avermectin in muscle,hepatopancreas and hemolymph respectively ranged from 89.4%～102.4%,95.3%～98.9%,86.7～100.6%, The intra-day coefficient of variation respectively was 2.1%～7.2%,2.0～4.3%,3.9～7.9%,The inter-day coefficient of variation respectively was 5.5%～8.4%,6.4～8.0%,5.3～8.9%, and the limit of detection (3S/N) respectively was 0.002ug/ml,0.004ug/ml,0.004ug/ml. The average recovery of water sample ranged from, 88.8%～95.7%, The intra-day coefficient of variation was 3.3%～5.4%,The inter-day coefficientAccording to the experiment of the toxicity of abamectin on Macrobrachium nipponense,we determined the dosage of AVM on Macrobrachium nipponense pharmacokinetic experiment, the concentration was 0.005 ug/ml, developed the pharmacokinetic study based on this. Under the 22 ~ 25℃water temperature of the experiment, the method of using medicine bath per 24h change potions once,change constant half, maintain liquid drug concentration, lasting 21d; After 21d per 24h change not adding abamectin experimental water until the 40d. Results showed that the AVM concentration in Macrobrachium nipponense descendeded order of highest concentration of hepatopancreas, hemolymph, muscles. when the concentration of muscle, hepatopancreas, hemolymph of Macrobrachium nipponense have reached the highest value of the AVM and maintained stable in 20d. Among them, the highest concentration in the hepatopancreas was 98.60ug / l, followed by the haemolymph and muscle tissue were 28.68ug / l and 15.44ug / l. After21days stop to drugs, the AVM concentration in each tissue gradually declined, each tissue can't detect AVM till 40 days. Due to the species differences, physiological differences, certifacate administration dosage, give medicine way diameter, salinity, temperature, pH value of such factors as all can affect aquatic organisms pharmacokinetic residue, the same drugs in different aquatic organisms pharmacokinetic parameters are different. Therefore be care of choosing a hydrobiological clinical administration dosage and Hugh medicine period to another application of aquatic creatures. the concentration of AVM to 0.005 ug/ml for medicine for 20 days in this experiment , advised its Hugh medicine period 20 days for the shortest. Studied pathological changes of Macrobrachium nipponense exposed to different concentrations of abamectin, the results showed that Macrobrachium nipponense exposed to the AVM concentration of 0.005mg / l or more continuous dipping 27days ,The hepatopancreas, antennal gland, gill of Macrobrachium nipponense began to appear in varying degrees tissue damages, including hepatopancreas in the 0.01mg/l concentrations were observed to significantly swelling, liver and ltubler between the closely arranged, tube lumen fused and blurred,there was a serious hepatopancreas pathology,hepatopancreas vacuolar degeneration , nuclear swelling, dissolution or even disappear, also appeared in the shrimp partial body that hepatopancreas cell necrosis till 27days; Antennal gland exposed to the concentration of 0.01mg/l AVM for 23days, we found that the cells of acrocyst, nephridium and labyrinthine emerged many of the cell nucleus concentration, cell swelling, membrane rupture, tissue fluid out of the nucleolus to the cytoplasm scattered space, also found that some cell death, tissue of a large number of voids; nucleus concentration, cell swelling, membrane rupture, tissue fluid out of the nucleolus to the cytoplasm scattered space, also found that some cell death, tissue of a large number of voids; gill exposed to the concentration of 0.01mg/l AVM for 23days, part of epithelial cells in gills of enrichment , telangiectasia, basement membrane hypertrophy, significant swelling of gill filaments at the end, Gill filaments epithelial hyperplasia, nuclei enlargement cause epithelial cells jams, filaments acknowledged by the orderly 2-3 layers of cells into no regularly arranged multi-layered cells.We also can observed when the gill arch cartilage degeneration till 27 days, some nuclei were spindle-shaped cartilage, some cells off into the cytoplasm; intestine exposed to the concentration 0.01mg/l for 23days, intestinal epithelial cells can be observed swelling, vacuolar degeneration of some single cell necrosis, telangiectasia within the intestinal villi, congestion. Therefore, the normal habitat of Macrobrachium nipponense safe concentration in the AVM can not be higher than 0.005 mg / L.Reported the status of AVM residues in Macrobrachium nipponensis muscle in parts of shanghai pudong new area. The result shows that the four test markets the AVM residues in Macrobrachium nipponensis muscle meet the national food safety requirements, citizens can be safe to eat.