title: Effect of treatment protocol and sample time on the frequencies of micronucleated polychromatic erythrocytes in mouse bone marrow and peripheral blood.
abstract: Studies were conducted to evaluate the effect of experimental protocol on the ability of benzidine (BZD), dimethylbenzanthracene (DMBA) and mitomycin C (MMC), administered by intraperitoneal injection, to induce micronuclei in polychromatic erythrocytes (PCE) of B6C3F1 mice. Three different treatment/sampling protocols were used, involving from one to three consecutive daily treatments and from three to one, respectively, consecutive daily samplings beginning 24 h after the last injection. DMBA and MMC elicited a significant micronucleus response in all three experimental protocols, while BZD induced a significant response only in the multiple injection protocols. Of the three protocols, the 3-day injection/single sample time protocol offers the greatest efficiency in minimizing the number of animals required in a study, in decreasing the time needed for scoring and in simplifying the statistical analysis. In addition, a comparison of the frequency of micronucleated PCE in peripheral blood and bone marrow following the treatment of mice with either BZD or DMBA suggests that, following a three injection protocol, either tissue can be used with equal efficacy.
authors.affiliation: Integrated Laboratory Systems, Research Triangle Park, NC 27709.
authors.forename: R R
authors.initials: RR
authors.lastname: Tice
authors.forename: G L
authors.initials: GL
authors.lastname: Erexson
authors.forename: C J
authors.initials: CJ
authors.lastname: Hilliard
authors.forename: J L
authors.initials: JL
authors.lastname: Huston
authors.forename: R M
authors.initials: RM
authors.lastname: Boehm
authors.forename: D
authors.initials: D
authors.lastname: Gulati
authors.forename: M D
authors.initials: MD
authors.lastname: Shelby
mesh_terms: D015127:9,10-Dimethyl-1,2-benzanthracene / Q000008:administration & dosage / Q000633:toxicity*; D000704:Analysis of Variance; D000818:Animals; D001560:Benzidines / Q000008:administration & dosage / Q000633:toxicity*; D001853:Bone Marrow / Q000187:drug effects; D001854:Bone Marrow Cells; D002869:Chromosome Aberrations; D004912:Erythrocytes / Q000187:drug effects; D007274:Injections, Intraperitoneal; D008297:Male; D051379:Mice; D015162:Micronucleus Tests; D016685:Mitomycin; D008937:Mitomycins / Q000008:administration & dosage / Q000633:toxicity*; D012044:Regression Analysis
chemical_list: D001560:Benzidines; D008937:Mitomycins; C029876:benzidine; D016685:Mitomycin; D015127:9,10-Dimethyl-1,2-benzanthracene