Study On DNA Damage Induced By High Fluoride And Low Iodine In Aged Rats

[objective] Single cell gel electrophoresis (SCGE) was practiced in the study on DNA damage induced by high fluoride, low iodine or both high fluoride and low iodine in aged rats ,with an attempt to explore the mechanism of fluorosis and the relationship between high fluoride and low iodine. [Method] The experimental models were set up by treating Wistar albino rats with water fluoride (100mgNaF/L), diet from the area of low iodine (0.0855mg/kg), or both water fluoride and low iodine respectively. The samples of brain, thyroid gland, liver, spleen, lung and kidney were obtained by rats'decapitation at 20 months old and were made into unicellular liquid respectively for SCGE. [Results] ⑴The DNA damage happened in all organ cells of aged rats treated with high fluoride at different degree. The hang-tail rates of all sample cells were above 80%, except for kidney cell (66.43%). DNA damage of Brain and kidney cell mainly showed Ⅱgrade damage, but Ⅲgrade damage in lung be in the ascendant. Ⅱand Ⅲgrade damage were nearly equal in thyroid gland, liver and spleen cell respectively. The tail lengths of comet cell of all organs in group treated with high fluoride were increased compared with that of control group (P< 0.05). ⑵The lack or rupture of single-chain DNA of all experimental samples were induced by low iodine and Ⅱgrade damage were observed. The hang-tail rate of all sample cells was above 83.03%.