[The pharmacokinetics and metabolism of heptapeptide--a prospective synthetic analog of tuftsin with psychostimulating action in rats].

The pharmacokinetics of a new heptapeptide with psychotropic activity was studied in rats in experiments in vitro and in vivo by means of high-performance liquid chromatography. The heptapeptide was detected in its natural form in rat blood plasma for 7-10 min; its T1/2 exceeded that of other oligopeptides of similar structure. The structure of the main pharmacologically active heptapeptide metabolite was identified by high performance liquid chromatography; it proved to be tetrapeptide Thr-Lys-Pro-Arg (taphtsin). The heptapeptide was distributed in well vascularized organs of rats: liver > kidneys > heart.