Sister Chromatid Exchange in Murine Alveolar Macrophages, Regenerating Liver and Bone Marrow Cells--a Simultaneous Multicellular in Vivo Assay

Differential labeling of sister chromatids was achieved simultaneously in murine alveolar macrophages, regenerating liver, and bone marrow cells of partially hepatectomized mice as well as in alveolar macrophages and bone marrow cells of nonhepatectomized mice. The mean frequency of SCE/cell +/-S.D. and the percentage of second division cells for each cell type were determined. No significant differences in mean frequencies of SCE/cell were observed among the cell types or between hepatectomized (alveolar macrophages--3.6+/-2.2, bone marrow--3.4+/-2.2; regenerating liver--3.6+/-2.4) and nonhepatectomized (alveolar macrophages--3.4+/-1.9; bone marrow--2.9+/-1.8). Although the percentage of second division cells was dependent upon cell type, no significant differences were apparent between hepatectomized (alveolar macrophages--57+/-8%; bone marrow--37+/-6%; regenerating liver--65+/-6%) and nonhepatectomized mice )alveolar macrophages--53+/-6%; bone marrow--36+/-4%). Comparisons between BrdU treated and nontreated nonhepatectomized mice revealed no significant alteration in mitotic yields.