The growth effects of gamma-ray irradiation on third-stage larvae of Angiostrongylus cantonensis in snail.

In order to clarify growth effects of gamma-ray irradiation on the third-stage larvae of Angiostrongylus cantonensis, snails naturally infected with larvae of A. cantonensis were irradiated with a cobalt-60 source, and the total dosage of exposure was 0.1 kGy. Third-stage larvae were collected from each group of irradiated and non-irradiated snails and then administered to rats. A significant reduction was observed in the number of recovery worms from rats sacrificed at 45 days after infection compared with the control group. Moreover, there was an increase in the percentage of female worms, and the body length of the irradiated group's worms was significantly shorter than that of the control group. In ultrastructural observations by transmission electron microscope, the cuticle was thickened and the subcuticle showed partial vacuolization and separation from muscle in the irradiated group. In addition, the muscles myofibril became shorter, the microvilli of intestinal mucosa were shorter and irregular, the terminal web disappeared, and the phagocytic vesicles, mitochondria, lysosomes and secretion granules decreased in number, respectively. Focusing on the mitochondria of the epithelial cells of the intestine, there were degenerative changes in the irradiated group showing vacuolization. The gonads of female worms recovered from the irradiated group revealed degenerative vacuolization, and the gonads of male worms could not be found.