Effect of iodine excess on morphology of mouse thyroid follicle and pancreatic acinar cells

Abstract

Objective To explore the effect of different levels of iodine excess on morphological changes of mouse thyroid follicle and pancreatic acinar cells. Methods Sixty female mice (BALB/c) were selected and their body weight were 18-22 g. The mice were divided into 6 groups according to body weight via the random number table method, 10 mice in each group. Potassium iodate was added to drinking water in exposure groups with iodine contents of 300, 600, 1 200, 2 400, and 4 800 μg/L, while normal group (control) was given normal levels of iodine (5 μg/L) tap water. After feeding for one month, the thyroid and pancreas of the mice were harvested, and the morphology of thyroid follicle and pancreatic acinar cells were observed through light microscope and ultrastructural changes of pancreas were observed through electron microscope. Results After one month of feeding, mice in the high iodine drinking water groups, starting from the 1 200 μg/L group, thyroid follicular cavity gradually enlarged and cells became flat; swollen and vacuolar-like deformation were observed in the mouse pancreas acinar cells under light microscope. Under the electron microscope, the ultrastructure of pancreatic acinar cells changed significantly starting from the 600 μg/L group, the number of zymogens decreased, organelle degeneration and necrosis, and endoplasmic reticulum expanded. Conclusion Iodine excess can cause damage to pancreatic acinar cells in mice. Key words: Iodine; Mice; Pancreatic acinar cells; Thyroid gland; Endoplasmic reticulum stress