STUDIES ON METABOLISM OF14C-LABELED CEFTEZOLE

• Published in: CHEMOTHERAPY Vol. 24; no. 4; pp. 655 - 670
• Main Authors: TOHIRA, YASUO, KAMIYAMA, HIROSHI, HINOHARA, YOSHIKAZU, SUZUKI, HIDETAKA, HARADA, YUSUKE, SUZUKI, SHIGEO, TAKANASHI, SHIGERU
• Format: Journal Article
• Language: Japanese
• Published: Japanese Society of Chemotherapy 20.04.1976
• ISSN: 0009-3165; 1884-5894
• DOI: 10.11250/chemotherapy1953.24.655

Absorption, excretion, tissue distribution and bio-transformation of ceftezole (CTZ), a new semisynthetic cephalosporin antibiotic, were investigated in rats and rabbits following intravenous or intramuscular injection of 14C-CTZ. Those of cefazolin (CEZ) were investigated similarly in order to compare with CTZ, farther metabolic differences in sex were studied in rats. In whole-body autoradiograms of rats 15 minutes after injection, considerable radioactivity was observed throughout the body and high radioactivity was distributed in kidneys, urinary bladder and intestinal contents, whereas no radioactivity was found at all in fetuses. Blood half-life of CTZ in rats and rabbits given intravenously was 22 minutes, and when given intramuscularly, that in both animals was prolonged. On the other hand, blood half-life of CEZ after intravenous injection was 36 minutes in rats and 46 minutes in rabbits. Within 24 hours 5.6% of the administered radioactivity of CTZ was recovered in bile of rats given intravenously and the biliary excretion of CEZ was higher than that of CTZ. Within 1 hour after injection_55.7% of the intravenously administered CTZ was excreted in urine of rats, 66.4% in urine of rabbits, indicating a rapid excretion of this antibiotic via urine. The studies on metabolites by autoradiography, radioscanning and autobiography of thin layer chromatograms of urine and bile revealed that no radioactive and biologically active metabolite was present both in urine and bile. Reverse isotope dilution analysis showed that CTZ was scarcely metabolized in the body. Disapearance of radioactivity was observed to be rapid in all tissues analyzed and no significant difference in sex was found between female and male rats.