抄録
When streptomycin (10mg) was injected every other day, urinary excretion of vitamin B_<12> for 45 to 46 hours after injection increased considerably for about two weeks, but the administration of chloramphenicol caused a prompt decrease. In the case of injection of both streptomycin (10mg) and vitamin B_<12> (1μg) every other day, the excretion of vitamin B_<12> in the 45 hours urine increased markedly on the 12th-14th day and decreased again on and after the 18th day. When streptomycin was injected intramuscularly every other day for three weeks, a marked increase of vitamin B_<12> content in liver tissue and blood was observed. The results of these experiments suggest changes in the balance of intestinal bacterial flora by the antibiotics.
