Effects of Antitumor Agents on Ultrastructure of the Splenic White Pulp of the Mouse Implanted with Ehrlich Carcinoma Cells

Ko, Jeong Sik; Lee, Joo Han; Ahn, E Tay; Park, Kyung Ho; Kim, Jin Gook

Abstract

This experiment was performed to study the morphological responses of the splenic white pulp, the lymphatic tissue of the spleen, of Ehrlich carcinoma cell-implanted mice to three different anticancer drugs (5-fluorouracil, mitomycin C and AG60). Healthy adult ICR mice weighing 20 g each were divided into normal and experimental groups. In the experimental groups, each of mice was inoculated with 1X10(7) Ehrlich carcinoma cells subcutaneously in the inguinal area. From next day, 0.2 ml of saline solution, 5-fluorouracil (30 mg/kg), mitomycin C (400 microgram/kg) or AG60 (30 mg/kg, Taerim Pharm. Co., Seoul, Korea) were injected subcutaneously every other day, and animals were sacrificed at 14th day following the f irst injection. Pieces of the tissues were taken from the spleen, and prefixed with phosphate buffered 2.5% paraformaldehyde-1.5% glutaraldehyde solution (pH 7.3) followed by post-fixation with phosphate buffered 1% osmium tetroxide solution (pH 7.3). Fixed tissue blocks were dehydrated, and embedded in araldite mixture. Ultrathin sections stained with uranyl acetate and lead citrate were observed with a JEM 100CX-II electron microscope. In the experimental control group (carcinoma cell-inoculated mouse), splenic white pulp did not show pronounced morphological alterations, but myelin figures were frequently observed in the cytoplasm of some lymphocytes and reticular cells than those of normal control mice. In the AG60 treated group, splenic white pulp did not show specific morphological defect, but nuclear bodies and severe invaginations of the nuclear envelope of the lymphocytes and reticular cells were observed occasionally. In the mitomycin C treated group, myelin figures, severe invaginations of the nuclear envelope, nuclear protrusions, nuclear bodies and interchromatin granules were frequently observed in the lymphocytes and reticular cells of the white pulp. In the 5-f luorouracil treated group, myelin f igures, severe invaginations of the nuclear envelope, nuclear protrusions, nuclear bodies and interchromatin granules were observed more frequently in the lymphocytes and reticular cells of the white pulp, as compared with those of mitomycin C treated mice. From the above results, 5-f luorouracil or mitomycin C may suppress the splenic immune function of cancerinoculated mice, since they suppress the process of differentiation and maturation of splenic lymphocyte and reticular cells, and 5-fluorouracil was more harmful on the spleen than mitomycin C. Whereas AG60 does not affect remarkably the process of differentiation and maturation of lymphocytes and reticular cells in the splenic white pulp.