Toxokinetics Of Scopolamine In Rats

Objective(s)Using scopolamine hydrobromide monomer,the metabolism of scopolamine in rats was studied by toxicokinetics,tissue distribution,blood biochemical tests,metabolites,metabolomics and pathology tests.Method(s)1.Toxicokinetics:Twelve SD rats were randomly divided into two groups,namely high-dose group(100mg/kg)and low-dose group(25mg/kg),with 6 rats in each group.Tail venous blood(about 400 μ L)was collected at 3min,10min,20min,30min,1h,2h,4h,8h,12h,24h and 48h after single gavage.HPLC-MS/MS was used for detection,and a series of pharmacokinetic parameters were obtained by combining with pharmacokinetic analysis software.2.Tissue distribution:Eighteen SD rats were randomly divided into 3 groups,namely 10min administration group,30min administration group,and 2h administration group,with 6 rats in each group.All the 3 groups were given 100mg/kg,and the rats were anesthetized with ether at 10min,30min and 120min after single intragastric administration.The blood,heart,liver,spleen,lung.kidney.stomach,intestine,brain and other tissues of the rats were dissected quickly.HPLC-MS/MS was used to detect the scopolamine content in the tissues of the rats in each group,and the distribution pattern of the tissues was obtained.3.Blood Biochemistry:Blood samples were collected from 10 SD rats before administration as the blank group.Blood samples were collected as the administration group after 7 days of remission after single intragastric administration.The automatic blood biochemistry instrument was used for detection,combined with statistical software to screen out theDifferential blood biochemical indicators.4.Metabolites and metabolomics:Forty SD rats were divided into control group and 3 different dose groups.The long-term poisoning model was established after continuous administration for 30 days.The endogenous metabolites and toxic metabolites in serum and urine of different groups of rats were analyzed by GC/MSD and UPLC-MS/M S detection combined with multivariate analysis and database retrieval.Screening and identifying potential endogenous differential metabolites and toxic metabolites;Metabolic pathway enrichment was performed by Metaboanalyst software.5.Pathological examination:The heart,liver,spleen,lung,kidney,stomach,intestine,brain and other tissues of rats in the long-term poisoning model group were taken to make paraffin sections for HE staining and then observed by microscope and photographed by pathological color map.Result(s)1.Toxicokinetics:The peak time(Tmax)of high and low administration groups were 0.528h and 0.472h.respectively,and the maximum plasma drug concentrations(Cmax)were 7766.665ng/mL and 964.250ng/mL,respectively.2.Tissue distribution:The tissue distribution characteristics of scopolamine content at 0.17h were stomach>,intestine>,liver>,kidney>,spleen>,lung>,heart>,brain>,blood.The tissue distribution characteristics of scopolamine content at the time point of 0.5h were stomach>kidney>intestine>lung>spleen>liver>blood>heart>brain.The tissue distribution characteristics of scopolamine content at the time point of 2h were roughly stomach>,kidney>,heart>,intestine>,spleen>,lung>,liver>,brain>,blood.3.Blood biochemistry:the content of triglyceride(TG)was up-regulated,and the content of low density lipoprotein cholesterol(LDL-C)was down-regulated,P<0.05,and the difference was statistically significant.There were no statistical changes in other blood biochemical indexes.4.Metabolites:Scopolamine nitrogen oxides,dehydrated scopolamine and tropic acid were identified in serum of low-dose group of rats with long-term poisoning,but no scopolamine metabolites were found in other groups and urine.None of the above metabolites were detected in blank serum and urine.5.Metabolomics:a long-term drug poisoning model set of serum and urine of the communist party of China selected glutamic acid,glycine,proline,creatine,the difference of alanine 17 kinds of metabolites,mainly involving alanine-aspartic acid,glutam ic acid metabolism,glycine,serine and threonine metabolism,glutamine-nine metabolic pathways,such as glutamic acid metabolism.6.Pathological examination:mainly nerve cell degeneration.Conclusion(s)Toxicokinetics,tissue distribution,blood biochemistry,metaboli tes,metabolomics and pathological tests revealed that the distribution characteristics of scopolamine in blood at different toxic doses were consistent with the two-compartment model,and the peak time of blood concentration(Tmax)was 0.528h and 0.472h,respectively.The maximum plasma drug concentrations(Cmax)were 7766.665ng/mL and 964.250ng/mL,respectively.In the main tissues,it was m ainly distributed in the stomach and intestine at the absorption stage,and mainly distributed in the stomach and kidney at the equilibrium and elimination stage.At higher doses,oxidation,dehydration and hydrolysis products were identified in serum as scopolamine NOx,dehydrated scopolamine and tropic acid,respectively.It also revealed the toxic effect of scopolamine on the central nervous system,causing changes in blood biochemical indexes,metabolic pathways and degeneration of nerve cells.Based on the above research,it provides reference and theoretical basis for the extraction of samples,the screening of poisoning markers,the judgment of poisoning degree,the judgment of poisoning time,the clinical rational drug use,the treatment of poisoning patients,and the research and development of antidote..