SUPPRESSION OF TRITIUM GAS OXIDATION IN RAT BY NORFLOXACIN AND CLINDAMYCIN

To determine whether intestinal anaerobes are the principal agents res ponsible for oxidation of tritium gas (HT) in the intestine, the suppr essive effects of an antibacterial drug, norfloxacin, and an antibioti c, clindamycin, on tritium uptake in rat exposed to HT were investigat ed. The administration of norfloxacin or clindamycin to rat was starte d 1, 2, 3 or 4 days prior to exposure and continued until just before exposure to HT. Following exposure to HT for 2 h, the tritium concentr ation of tissues and blood was determined. Tritium concentration in bl ood decreased in proportion to the period of drug administration. In t he case of clindamycin, the tritium concentration in the body of the r at decreased to 12% that in control rat. Norfloxacin was less effectiv e than clindamycin. When the administration of clindamycin was begun o n the day of exposure and continued for 4 days, the biological half li fe of urinary tritium in the treated rat was shortened to 53% that in the control rat.