Amide Class Module Medicine Apap In Silkworm Body Metabolic Pathways Of Study

Acetaminophen (APAP) is an operative medicine widely used for the treatment offever and analgesia, and is a pattern drug of amide class widely used for liver injury model,too. Along with the conversion of medicine research pattern, the alternatives to animaltesting have become an important aspect of toxicology development. For drug toxicity test,the experimental animals used are mostly mammals such as mice. The drug administeredby orally exposure stays in the stomach for a relatively long period, and are easily digestedby gastric fluid, making the observation of the influence of drug on digestive tract difficult.In this study, Bombyx mori as an invertebrate, was used as the experimental animal.1Appropriate dose of APAP in Bombyx larvaeOne of the topic problems for alternatives to animal testing is the conversion of dose.Before, there is no reliable formula for the dose of clinical drugs from mice and human tosilkworm. According to the experiment the LD50of APAP in silkworm is2450.3~3226.85mg/kg, over50%more than1664.7mg/kg which got by the empiricalformula. Our results showed that a safe dose for day2of5th instar larvae of haoyue strainis600mg/kg, while the damage dose is3600mg/kg and the critical dose is1800mg/kg.2The metabolites of APAP in multiple tissues of Bombyx larvaeThe HPLC results showed that the products of glycosylation and sulfation are the twomain metabolites of APAP in multiple tissues of Bombyx larvae after orally explosion on2d of5thinstar. The metabolites are similar with the mice. There are tissue metabolismdifferences of APAP in Bombyx larvae, the glycosylation metabolic target organ might bedigestive tract while sulfation target organ might be haemolymph.The silkgland is a special organ in Bombyx larvae instead of in mice or human. Thesilkworm larvae are able to transfer the original medicine of APAP to the silkgland viahaemolymph from digestive tract, and the physiological effect might be store the redundantAPAP and the critical concentration could be0.2mg/ml at this stage. This phenomenon isuseful for the long-term toxicology studies.3Changes of activities of UGTs and its gene expression levelsThe activity of UGTs in digestive tract is higher than that in fat body on a2d of5thinstar larva of silkworm. However, this activity increased in digestive tract andhaemolymph start at24min and16min, respectively, after oral exposed to600mg/kg APAP.While the active is rapid rised in fat body, showed2times higher than its positive control at8min, and5times at24min, and suggested that the fat body is very sensitive to APAPbut might not been a main metabolic tissue.The results of gene expression patterns showed that Ugt30, Ugt86and Ugt89are allupregulated expression level in digestive tract and fat body. A peek level of Ugt30andUgt89gene mRNA in digestive tract presents to30min later, while they slowly increasedin the fatbody, supported the above results and guess.4The injury in silkmorm tissues caused by APAPAfter oral injected APAP of3600mg/kg, the larvae showed behaviors of sluggish andfeeding disturbance, accompanied by vomiting and body poisoning symptoms such asshrinkage even melanism at2hours later. The results from morphology and sectionsshowed that there were local fester in digestive tract. The structure of tunica intima wasseverely damaged, and the microvilli distinguish and cytomembranes of mast and gobletcells were damaged gravely. Follow the cells of fat body shorten then become a circle at12hours later, while the intracellular cavitations increased and the cytomembrane thickenedor damaged, the even losed nuclei, indicated that the fat body was suffered serious damageby APAP.ROS was temporary increased in digestive tract at8min after oral injected3600mg/kg of APAP, nevertheless the ROS was almost disappeared at the quite late of12h-18h,and even the tissue was serious injured, suggested that the damage of APAP may not been aoxidative damage pathway as a common drug in the digestive tract. The ROS inhematopoietic organs was been increasing in32min and was recovered gradually after12h,meanwhile, the hematocyte has not been cut significantly than control. These resultsindicated that the blood cell injury in vivo induced by APAP is different from that in mice.