ABSTRACT
To study the dynamic process of myocardial uptake of thiopentai in the isolated rabbit hearts. Method: Thiopental at doses of 500?mol, 1500?mol and 500?mol was given sequentially to the perfused rabbit heart in a total time of 15 min. The outflow concentration of thiopental was measured with high performance liquid chromatography and the left ventricular +dp/dtmax served as a effective parameter. Resuh: The disposition and elimination of thiopental can be best described hy a two-compartment open model. It can disposed into myocardium rapidly (T_(1/2)?=0.5?0.1 min), but elimination was relatively slow (T_(1/2)?=25.3?10.1 min). The transfer rate was slower from peripheral to central compartment than from central to peripheral compartment. The tbeoritical maximum depressant effect of thiopental on + dp/dt (Emax) was 19.0 4-11.2 kPa.s~(-1) corresponding to 1/10 E_0. Conclusion: The myocardial uptake of thiopental can be fitted to a two-compartment open model with rapid disposition and relative slow elimination process.