1987 Volume 2 Issue 5 Pages 497-507
The machanism of intestinal absorption of amino-β-lactam antibiotics was studied using 125I labelled cefatrizine of high radioactivity in rat by in situ ligated loop method and in vitro intestinal segment method. Iodocefatrizine (125I-CFT) retained the same antimicrobial activity and intestinal permeability as cefatrizine.
125I-CFT was taken up by the tissue against a concentration gradient. The tissue accumulation of 125I-CFT was highly temperature dependent and was inhibited by metabolic inhibitors. The rate of 125I-CFT uptake was decreased in the presence various amino-cephalosporins, amino-penicillins and dipeptides in the medium, but not affected by mono-carboxyl cephalosporins and amino acids. These results demonstrate that 125I-CFT is absorbed through the intestinal tissue by the carriermediated transport system.
In addition, the usefulness of application of 125I-labelled compounds, which can be easily prepared with very high specific radioactivity, in the biochemical pharmacology studies was also exemplified.
