Studies on the Distribution and Degradation of ³⁵S-Labeled Penicillin G in the Body

Abstract

Several biological assay methods have been used usually to investigate the pharmacology of penicillin. Even though biological methods of penicillin assay are sensitive and very useful, however, they have somehow limitations inherent to themselves. Recently many radioisotope techniques have been used for the investigations of antibiotics with pharmacological and biochemical respects. Rowlands et al.¹⁾ (1948) reported the excretion of biosynthetized radioactive penicillin in the unne. Sebek²⁾ also reported the method of biosynthesis of ¹⁴C-labeled benzylpenicillin. Radioactive antibiotics, ¹⁴C-oxytetracycline,^{3,4,5) 3}H-tetracycline⁶ , ³H-dehydrostreptomycin6l and ¹⁴C-chloramphenicol etc., have been studied by several investigators. These research works by use of the radioactive tracers can be devided into two ways, to study the distribution of antibiotics in the body tissue quantitatively on one side, and to illustrate the tissue distribution with autoradiographically on the other side. More detailed informations can be yielded by autoradiography in terms of histological site of distribution. Ullberg⁷ reported the tissue distribution of ³⁵S-labeled penicillin (³⁵S-PC) by use of autoradiographical method in detail.

In this paper, studies on the pharmacology of ³⁵S-PC compared with bioassay, the degradation of penicillin in the body and protein binding will be presented.