Effects Of Different Doses Of Potassium Iodide And Potassium Iodate On Plasma Antioxidant Capacity, Blood Lipid Metabolism And Thyroid Function In Rats

PurposesTo study the effects of different dose of potassium iodide and iodate on antioxidant ability of the blood plasma, lipid metabolism of the blood and thyroid function in rats; and to compare the effects between the two kinds of iodine additives.The results could provide reference to choose the appropriate iodine additives for Universal Salt Iodization.Methods116Wistar rats of the clean grade were chose. The rats were weaned two weeks and their weight were120g-140g. They were randomly divided into8groups according to their sex and body weight.4groups of them were given by different dosages of potassium iodide, and other4groups were given by different dosages of potassium iodate. The groups were1time dosage group with the iodine intake of6μ g/d per rat (KI group and KIO3group),10times dosage group with the iodine intake of60μ g/d per rat (10KI group and IOKIO3group),50times dosage group with the iodine intake of300μ g/d per rat (50KI group and50KIO3group) and100times dosage group with the iodine intake of600μ g/d per rat (100KI group and100KIO3group). There were10rats in each of the1time dosage groups, and there were16rats in each of the rest dosage groups. All groups got prospective iodine intake respectively, by controlling food and drinking water. Every1or2months, urinary iodine of the rats was tested.After12months, blood samples of the rats were collected through abdominal aortic, and blood plasma and serum were separated to detect the following items: antioxidant capacity of blood plasma, including superoxide dismutase (SOD), glutathione peroxide physical activity (GSH-Px), and malondialdehyde (MDA); lipid metabolism, including triglycerides (TG), total cholesterol (TC), high density lipoprotein cholesterol (HDL), low density lipoprotein cholesterol (LDL), apolipoprotein A1(apoAl), apolipoprotein B (apoB) and lecitnin cholesterolacyltransferase (LCAT); thyroid function, including Triiodothyronine (T3), free triiodothyronine three (FT3), thyroxine (T4) and free thyroxine (FT4).This study funned by the National Natural Science Fund Project (Contract No.81072246).Results1. Antioxidant capacity of the blood plasma in ratsDifferences between the groups with the same drug and different dosages:groups of potassium iodide:SOD activity,50KI group was lower than the rest groups; GSH-Px activity,100KI group was higher than the rest groups; MDA content, KI group was higher than the rest groups; groups of potassium iodate, SOD activity decreased in the50times and100times dosage groups.Differences between the groups with the different drugs and the same dosage: SOD and GSH-Px activity of the100KIO3group were both less than they in the100KI group.2. Lipid metabolism of the blood in ratsDifferences between the groups with the same drug and different dosages:groups of potassium iodide, the contents of TC, TG, HDL, LDL and Apoal in the1time the group were higher than the rest groups; groups of potassium iodate, content of LCAT in10KIO3group is higher than the rest groups.Differences between the groups with the different drugs and the same dosage:no statistical difference of the TC, TG, HDL and LDL levels was found between the groups of potassium iodide and potassium iodate with the same dosage; LCAT in10KI group was lower than it in10KIO3group; ApoAl content in KI group was above it in KIO3group, and ApoAl content in10KI was below it in10KIO3group, and ApoAl content in50KI was below it in50KIO3group; no statistical difference of ApoB levels was found between groups of potassium iodide and iodate potassium with the same dosage.3. Thyroid function in ratsDifferences between the groups with the same drug and different dosages:groups of potassium iodide, serum T4and FT4in1time group was lower than the rest groups; serum FT3level rose in the ten times and50times groups. Groups of potassium iodate, serum contents of T3and FT3in the10times the group was higher than the rest groups; Serum T4content in the10times group and50times were higher than1time group; Serum FT4content rose in the10times and50times groups.Differences between the groups with the different drugs and the same dosage:T3content in100KI group was below100KIO3group; T4level in100KI group was higher than it in100KIO3group; FT4content in KI group was below it in KIO3group.Conclusion1. Antioxidant capacity of the blood plasma:potassium iodide and iodate potassium with the dosage above300μ g/d per rat can affect the antioxidant capacity of the blood plasma. When the dosage reached600μ g/d per rat, peroxidation damage arose by the potassium iodate was stronger than potassium iodide.2. Lipid metabolism of the blood:lipid levels were significantly influenced by the different dosages of iodine, and it was not significantly influenced by the different forms of iodine.3. Thyroid function:when the iodine intake was6μ g/d per rat, the iodine deficiency caused the lack of thyroid hormone synthesis. Other than the potassium iodide, potassium iodate with the dosage of600μ g/d per rat could cause the inhibitory effect of thyroid hormone synthesis.4. Rats with iodine intake of6μ g/d per rat were in the state of iodine deficiency. When iodine intake of rats was60u g/d per rat, we did not see the phenomenon of iodine deficiency or iodine excess. Relative to the iodine deficiency, the tolerance of rats was stronger with the intake of high dosage iodine.5. It has the disadvantages, when the result is inferred from the animal experiment to human beings. The epidemiology investigations are needed for the final conclusion.