Objective To study toxicokinetic characteristics of metamitron in rat plasma and tissuse.
Methods High performance liquid chromatography coupled with ultraviolet detector method was used to determine the concentration of metamitron in rat blood, tissues, and excrement samples, and toxicokinetic parameters were analyzed.
Results The serum drug-time curves were consistent with first-order models of both male and female rats. The main toxicokinetic parameters for female and male rats were:t1/2 (Ka), 0.77 h and 0.69 h; t1/2(Ke), 7.34 h and 2.12 h; CL, 0.78 L/(h& #183;kg) and 2.59 L(/h& #183;kg); Vd, 10.75 L/kg and 8.33 L/kg; AUC, 1 594.07 mg/(L& #183;h) and 975.36 mg/(L& #183;h). The kinetic equations for male and female rats were C=8.79 (e-0.39t-e-1.04t) and C=4.96 (e-0.13t-e-2.01t), respectively. Concentrations of metamitron in liver, heart, and fat tissue were higher than those in plasma at the 4th hour after stomach lavaging with metamitron to the rats. The order of peak metamitron concentrations in rat tissues was:liver > heart > brain > spleen > fat > muscle > lung > kidney > testicle. The 7-day cumulative meramitron in feces and urine were 71.44% and 8.91%, respectively.
Conclusion Quick gavage absorption, wide distribution to varied tissues and organs, and elimination via feces and urine of metamitron are observed under the reported experimental settings.
DownLoad: