Effects of multiple dosing of phenacetin in the micronucleus test.
As a part of the international cooperative study to identify the most sensitive regimen in the micronucleus test, phenacetin was given i.p. to male CD-1 mice at doses of 37.5, 75, 150, 300, 400, and 600 mg/kg once, twice, thrice or four times and the bone marrow cells were harvested 24 h after the final dosing. Positive responses were seen at 600 mg/kg after single and triple dosing and at 400 and 600 mg/kg after double dosing. No dose level gave a positive response after quadruple dosing. A repeated-dosing effect was detected at double and triple dosing. Although triple dosing gave the highest magnitude of micronuclei at 600 mg/kg, double dosing showed a sufficient sensitivity and was more convenient from the viewpoint of selecting a suitable test dose and carrying out the micronucleus test.
Sutou
S
S
Itoham Central Research Institute, Ibaraki, Japan.
Kondo
M
M
Mitsui
Y
Y
D000818:Animals; D001853:Bone Marrow / Q000187:drug effects*; D001854:Bone Marrow Cells; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D004912:Erythrocytes / Q000187:drug effects / Q000648:ultrastructure; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D048629:Micronuclei, Chromosome-Defective / Q000187:drug effects*; D015162:Micronucleus Tests / Q000379:methods; D010615:Phenacetin / Q000008:administration & dosage / Q000494:pharmacology*; D012016:Reference Values
D010615:Phenacetin