Effects Of Different Dose Potassium Iodide And Potassium Iodate On Blood Antioxidant Capacity, Blood Lipid Level And Thyroid Function In Rats

PurposesTo prove the effect of different dose of potassium iodide and iodate on antioxidant ability, lipid metabolism and thyroid function in rats; and to compare the effect between the two kinds of iodine additives.The results could provide reference to choose safe iodine additives for Universal Salt Iodization.Methods104of SPF Wistar rats, weaning two weeks and weighing120g-140g,were randomly divided into eight groups according to their sex and body weight, There were14rats in each group, the control group with10. The potassium iodate groups included normal iodine group(KO)、10times dose group (10K0)、50times dose group (50K0)和100times dose group (100K0); The potassium iodide groups with the same4doses. All groups got prospective iodine intake respectively.By controlling food and drinking water, The amouts of KI and KIO3were as follows:normal iodine group with6μ g/d,10times dose group with60μ g/d,50times dose group with400μ g/d and100times dose group with800μ g/d, Every2months, urinary iodine of the rats was tested.After6months, collecting blood samples of the rats by abdominal aortic, separating serum and plasma to detect the following items:1. Antioxidant capacity of blood, including superoxide dismutase (SOD), glutathione peroxide physical activity (GSH-Px), and malondialdehyde (MDA).2. Lipid metabolism, including triglycerides (TG), total cholesterol (TC), high density lipoprotein cholesterol (HDL), low density lipoprotein cholesterol (LDL), apolipoprotein A1(apoA1),apolipoprotein B (apoB) and lecitnin cholesterolacyltransferase(LCAT)Thyroid function including Triiodothyronine (T3), free triiodothyronine three (FT3), thyroxine (T4) and free thyroxine (FT4).This experiment is a6months results, a part of the National Natural Science Fund Project.Results1. The rat blood antioxidant capacityThe blood GSH-Px activity of group10KI and group50KI increased, group100KI decreased. MDA content of group50K1and group100KI was lower than that of KI group.The GSH-Px activity of group10KO and group50KO were higher than that of group KO and the differences were statistically significant, but GSH-Px activity of group100KO was lower than that of group10KO and group50KO. SOD activity of Group10KO increased, but group100KO significantly reduced. MDA content of group100KO was significantly higher than that of group KO.The same dose of KI and KIO3on rat blood antioxidant capacity: GSH-Px activity, SOD activity between KI group and KIO3group had no significant difference. With the same dose (50times and100times), compared to the KI, activity of antioxidant enzymes of KIO3decreased, lipid peroxidation products increased.2. The rats blood lipid levelsIn the iodine dosage, serum lipid and lipid metabolism related enzyme had no difference. TC, TG, HDL, LDL, ApoAl, ApoB content between the high KI groups and KI group were no significant differences.TG content of group10KO, group50KO and group100KO increased significantly. LDL content of group100KO was higher than that of group KO significantly.3. The rat thyroid function of the ratsT3, T4content of100KI were higher than those of group KI, and the differencese were statistically significant, the FT3content of group10KI and group100KI decreased. FT4content of group10KI wad lower than group KI and the difference was statistically significant.T3, FT3, T4contents of group10KO, group100KO were significantly higher than those of group KO, but T4contents of group100KO and group50KO were less than group10KO.In10times and50times High iodine dose, T3、FT3content between KI and KIO3had significant differences. In100times high iodine dose, T4content between KI and KIO3had a significant difference. Conclusion1. The effect of KIO3on antioxidative activity was obvious than KI.100times of KI can decrease the blood antioxidant enzyme activities, there was no oxidative damage;50times and100times KIO3decreased blood antioxidant activities, increased lipid peroxides content(MDA).2. Excessive KI and KIO3increased TC content. In high KI groups,blood lipid metabolic parameters had no obvious changes;100times dose of potassium iodate made TC, TG, LDL contents increased significantly. Potassium iodide and iodate on lipid metabolism had no significant difference.3. The effects of excessive potassium iodide and iodate on thyroid function of rats were complicated.100times dose of potassium iodide and iodate increased T3, T4levels significantly, the effect of potassium iodide were significantly higher than that of potassium iodate.4. According to the experimental results:excessive potassium iodide and iodate affected the rat of blood antioxidant capacity, lipid metabolism and thyroid function, but two kinds of iodine agent had no significant difference, at the present stage, we can’t give a clear conclusion on the safety of potassium iodide and iodate.