Effects of Antitumor Agents to DNA Synthesis in the Gastric Epithelia of Mice Implanted with Ehrlich Carcinoma Cells: An Autoradiographic Study

Ko, Jeong Sik; Choi, Pil Cho; Ahn, E Tay; Park, Kyung Ho; Park, Dae Kyoon

Abstract

This experiment was performed to evaluate the morphological responses of the gastric epithelium of the mouse, inoculated with Ehrlich carcinoma cells, following administration of 5-fluorouracil, adriamycin or mitomycin C. Healthy adult ICR mice weighing 25 gm each were divided into normal control and experimental groups (tumor control group, 5-fluorouracil treated group, adriamycin treated group, and mitomycin C treated group). In the experimental groups, each mouse was inoculated with 1 x 10(7) Ehrlich carcinoma cells subcutaneously in the inguinal area. From next day after inoculations, 0.2 mL of saline, 5-fluorouracil (30 mg/kg), adriamycin (2 mg/kg) or mitomycin C (400 microgram/kg) were injected subcutaneously to the animals every other day, respectively. The day following the 7th injection of anticancer drugs, each mouse was injected with a single dose of 0.7 microCi/gm of methyl-3H-thymidine (25Ci/mmol, Amersham Lab., England) through tail vein. Seventy minutes after the thymidine injection, animals were sacrificed. The number of labeled epithelial cells in the gastric mucosae (mean number of labeled epithelial cells per 3.5 mm length of mucosa) were observed and calculated. On histological study, in the gastric mucosae of adriamycin-treated groups, denatured surface epithelial cells, expanded lumen of the gastric gland, and congested lamina propria were observed. But in the 5-fluorouracil or mitomycin treated groups, severe morphological changes of the gastric mucosae were not observed. On autoradiographic study, numbers of the labeled cells in the gastric mucosae per 3.5 mm length of normal control, tumor control, 5-fluorouracil-treated, adriamycin-treated and mitomycin C treated groups were 267.3 (+/-48.86), 273.6 (+/-59.41), 375.3 (+/-83.36), 15.3 (+/-9.66) and 124.0 (+/-32.66), respectively. In the adriamycin and mitomycin C-treated group, poorly-labeled cells containing only a few silver grains of 3H-thymidine were observed more frequently as compared in those of the normal control group. But in the 5-fluorouracil-treated group, number of the heavy labeled cells were observed more frequently than in those of the normal control group. From the above results, adriamycin and mitomycin C may severely suppress the DNA synthesis of the epithelial cells of the gastric mucosae. But some amount of the 5-fluorouracil (30 mg/kg) may not suppress the DNA synthesis of gastric epithelial cells.