FUNDAMENTAL STUDIES ON TRANSFER OF ANTIBIOTICS INTO ERYTHROCYTES. PART 1 THE IN VIVO EXPERIMENT IN MICE

Abstract

Distribution of penicillin G and other 7 antibiotics to the erythrocytes of male mice was investigated 1 and 4 hours after subcutaneous injections.
Their transfer into the erythrocytes was almost proportional to their concentrations and the drugs used were arranged in order of decreasing transfer : chlorabulin, chloramphenicol, tetracycline, streptomycin, penicillin G, erythromycin and aminobenzylpenicillin.
Concentrations of penicillin G and aminobenzylpenicillin which are water-soluble and weak acids in plasma, red cell membranes and intracellular materials of red cells were decreased in order of that in plasma, membranes and intracellular materials.
Concentrations of streptomycin and kanamycin which are water-soluble and weakly alkaline were decreased in order of that in plasma, membranes and intracellular materials. However, concentration in the membranes was almost equal to that in intracellular materials in the case of application of a small dose.Concentrations of tetracycline which is fat-soluble and a weakly acidic were decreased in order of that in plasma, intracellular materials and membranes.
Concentrations of erythromycin which is fat-soluble and a weakly alkaline were almost equal in plasma, membranes and intracellular materials.
Concentratoins of chloramphenicol and chlorabulin which are fat-soluble and neutral were decreased. in order of that in intracellular materials, plasma and membranes or in order of that in plasma, intracellular materials and membranes.
Although blood levels after 4 hours were lower than those after 1 hour, concentrations in red blood cells after 4 hours fell only slightly.