医薬品の生体内変化に関する研究(第66報) : Pantethineの生体内変化について

抄録

The metabolic fate of pantethine was studied with rabbits and rats using ¹⁴C-labeled compound. When it was injected subcutaneously to rabbits, the radioactivity was excreted into 24 hr urine in the amount varying from 40 to 90% of the dose administered, and almost nothing into feces. Rats also excreted most of the radioactivity rather quickly into urine. The radioactivity was distributed almost uniformly over all of the tissues of rats examined one hour after the drug administration. Two major radioactive metabolites were isolated from the urine of rabbits injected a large amount of ¹⁴C-pantethine (500mg/kg), and they were proved to be pantothenic acid and unchanged drug by comparison of their Rf values in thin-layer chromatogram and IR absorption spectra with those of the authentic samples. β-Alanine was also detected as a minor urinary metabolite by paper and thin-layer chromatographies. When injected 20mg/kg of ¹⁴C-pantethine, rabbits excreted unchanged pantethine, pantothenic acid, and β-alanine which accounted for about 15, 50, and 0.2% of the radioactivity in 24 hr urine.