Abstract:
Fourty mice, twenty male and twenty females were divided into five groups and given whole-day exposure of different levels of gamma radiation : 0, 150, 300, 600 and ‘750 rads. Two males and two females from each level were sacrificed after 24 hours, while the rest were sacrificed after one week. The testes and ovaries were studied histologically. This study aims to compare the effects of different levels of gamma radiation after 24 hours and to determine whether a regeneration or repair has occurred after one wee or not. It was found out that the spermatogonia were the most sensitive among the spermatogenic cells while the spermatozoa were the most resistant. At 150 and 300 rads, the spermatogonia were the most affected. At 600 rads, the spermatogonia were very few and some spermatocytes have disappeared. At 750 rads, only a few spermatocytes but much spermatids and spermatozoa were present. After one week, all levels showed a decrease in the number of cells, particularly the spermatogonia. At 600 rads, a new type of cell, having large, compact, dark-staining nucleus was observed. In the ovaries, it was observed that the most sensitive were the primordial and primary follicles while the Graafian follicles were more resistant. In the 300 rads, a cyst surrounded by columnar epithelium was observe. Perimordial and primary follicles decrease continuously as the dose increased. Likewise, many secondary follicles showed atresia. After one week, the ovaries showed many empty spaces within the organ, signifying great degeneration of the follicles. The follicles, especially the primordial and primary ones showed a decrease in number. It was concluded that after one week, regeneration has not yet taken place in all the doses used here. But if regeneration were to occur after one week, it can be said that the gonads exposed to the higher doses, 600 and 750 would need longer time to recover because here, the stem cells were almost totally wipe out.
