Thiopental-
35S having a specific radioactivity of 13.2 mCi/mmole was synthesized from H
235SO
4 as the starting material through H
235S and thiourea-
35S. Radiochemical and chemical yields from H
235SO
4 were 80.3 and 85.7%, respectively. The isotope dilution analysis for the determination of commercial thiopental sodium preparations was investigated with the
35S-labeled thiopental, and it gave the mean recovery of 99.60±0.68%. This method was advantageous over other known official methods such as ultraviolet absorptiometry and gravimetric analysis in the precision and selectivity of the method. As the metabolites of thiopental in the liver of male rats, methionine, thiourea, inorganic sulfate, and several unidentified
35S-containing compounds were recognized by radiopaperscannography or reverse isotope dilution method. Metabolic rates of thiopental-
35S in rat liver were 0, 49.7, 59.2, and 60.2% at 15, 30, 90, and 120 minutes after its intraperitoneal injection, respectively. It was proved that a considerable amount of radioactivities arising from the injected
35S-labeled thiopental was distributed in rat brain within 15 minutes after its intraperitoneal adminstration, and that the rapid reduction in radioactivities was found to three-fifths of the original during the following 15 minutes.
抄録全体を表示