Study of the ultrastructural changes in the thyroid gland of rats exposed to pulsed electromagnetic wave(PEMW)

摘要

Objective To observe the effects of exposure to PEMW (Pulsed electromagnetic wave) on function and morphology of the Thyroid gland of rats. Methods At different time points (24h, 48h, 96h, 8d) after exposure to PEMW (E=l15 kV·m~(-1),12000pulses), radioimmuno-assay was performed to observe the levels of thyroid-stimulating hormone (TSH), thyroxine (T4) and triiodothyronine(T3) in sera of those male SD rats; the optics microscope and the transmission electron microscope were used to observe the structural changes of thyroid gland as the indicated time points respectively. Results The T_3、T_4 and TSH in sera all increased significantly to the peak at 24 h, then gradually decreased. Although there were no obvious changes under the optics microscope, some ultrastructral changes had been found under the transmission electron microscope in thyroid gland. Ultrastructures were obviously changed at 12h and aggravated after 12 h until 48 h. In these rats, dilatated endoplasmic reticulum gathered with lots of protein excretion, lipid droplet and the heterochromatin gathered under the nucleus membranes were observed in follicular epithelial cells. These changes were palliated at 96 h but not recovered.Conclusion PEMW can affect levels of hormones in sera and the hazard ultrastructual changes of thyroid gland. Endoplasmic reticulum is the main injured organelle.