Effects of ionizing radiation on argyrophil cells of murine small intestine

The dose-effect relationship of enteroendocrine cells of mouse small intestine and their dynamic changes after irradiation have been investigated. One series of experiment was done on 43 groups of male LACA mice, which were subjected to whole-body 60Co γ-irradiation of 1 ∼ 160 Gy. All animals were sacrificed 72 hours after irradiation. Their whole small intestines were removed for preparing longitudinal histological sections, which were stained with modified Grimelius' method and the number of argrophil cells (AC) was counted. Another series of experiment was done on mice irradiated with 8, 10, 15, 20, and 30 Gy, which were sacrificed at different internals after irradiation. The average number of AC per each longitudinal section was 2942 +- 105.15 in the controls. After 1 ∼ 7 Gy irradiation the number of AC increased gradually, the highest level being 180% of the normal (7 Gy), then it began to decrease. In 160 Gy group, the number was only 11.52% of the normal. The number of AC fell by 40 ∼ 60% on the 1st day after 8 and 10 Gy irradiation, it rose again on the 2nd to 3rd days, overshot on the 4th to 7th days and recovered to normal level between 2 ∼ 4 weeks. After 15 and 20 Gy γ-exposure the number decreased by about 60% on the 1st day and increased slightly on the 2nd, but reduced again on the 3rd to 5th. With 30 Gy irradiation no recovery was observed at all. Based on the obtained results, the AC of small intestine was considered to be sensitive to radiation. On the other hand, it also has rather high repair capacity for radiation injury