1998 Volume 23 Issue 3 Pages 189-195
The usefulness of cellular size measurement for differentiating erythroid and myeloid cells was investigated using rat and canine bone marrow film prepared by the Cytospin method and Wright-Giemsa staining. 1.In the erythroid series, basophilic and polychromatic erythroblasts were distinguishable in terms of cellular diameter;i.e., 99% of rat and 95% of canine polychromatic erythroblasts were distributed in a range≤9.5μm, at which basophilic erythroblasts did not exist. 2.In the myeloid series, myelocytes and metamyelocytes were to some extent distinguishable by their diameters;in rats, myelocytes(75% of the population)were≥13.5μm, and metamyelocytes(61%)≤11μm;and in dogs, myelocytes(45%)were≥16μm, and metamyelocytes(66%)≤12μm. 3.With regard to the metamyelocytes and myelocytes existing in the same range, their nuclear sizes(width)allowed further differentiation;in rats, the nuclear width of myelocytes(87%)was≥5μm, and that of metamyelocytes(84%)<5μm;and in dogs, myelocytes(96%)≥7μm, and metamyelocytes(88%)<7μm. The present results indicate that cellular size, together with nuclear size, contribute to distinguish the active mitotic group from less-or non-mitotic group in erythroids and myeloids, thus being helpful for toxicological evaluation on chemicals.