Study On A Rat Model Of Experimental Autoimmune Thyroiditis With Liver Depression And Spleen Deficiency

Purpose:To observe the changes of thyroid function and the effect of high iodine on thyroid function in model rats during the construction of experimental autoimmune thyroiditis(EAT)liver depression and spleen deficiency syndrome combined model,and evaluate the EAT disease and syndrome combined model.Material and method:In this part of the study,female SPD SD female rats weighing180-220 g were selected and fed adaptively for 1 week after purchase.The rats were randomly divided into normal and model groups.Rats in the normal group were raised naturally without any stimulation.The model group rats were modeled by "immunization-mediated + high iodine water induction combined with chronic restraint stress+ excessive fatigue + diet loss" method.From the 8th day,except for normal group rats fed with distilled water,the rest of the rats were drinking concentrations 500 mg / L of iodine.On the 22 nd day,rats were immunized for the first time,and multiple points of subcutaneous injections of fully Freund's adjuvant(CFA)fully emulsified porcine thyroglobulin(Tg)were injected subcutaneously on the back,each injection of 100 ?g Tg,twice a week.On the 29 th to56th days,booster immunization was performed.Multiple points of subcutaneous injection of incomplete Freund's adjuvant(IFA)Tg were injected subcutaneously on the back of rats,each injection was 100?g Tg,once a week.At the same time,the rats are restrained in a restraint tube for 3 hours every day at 8:00 in the morning,and the rats are put into a large plastic bucket filled with warm water to swim until exhaustion at 1:00 in the afternoon.And fast every other day and give plenty of food every other day.On days 57-84,12 rats were fed with500 mg / L iodized water,and the remaining rats were fed with non-iodized water.During the modeling process,rats were sacrificed at 4 weeks,6 weeks,8 weeks,10 weeks,and 12 weeks,and the following indicators were tested:(1)thyroid weight index;(2)five functions of Jiagong;(3)liver depression and spleen deficiency Related indicators.Results:1.Changes in the five items of serum nail function(FT3,FT4,TSH,TG-Ab,TPO-Ab):The levels of serum TPOAb and TGAb in the model group were higher than those in the normal group at 4 weeks,6 weeks,8 weeks,10 weeks and 12 weeks(P<0.05),and the levels of serum TPOAb and TGAb in the model group at 8 weeks,10 weeks and 12 weeks,it was significantly more than 2 times higher than the normal group,and the difference was statistically significant(P<0.05).The level of serum FT3 and FT4 in the model group showed an increasing trend compared with the normal group at the 4th week,but the difference was not statistically significant(P>0.05);At the 6th week,the levels of FT3 and FT4 in the model group were higher than those in the normal group,and the difference was statistically significant(P<0.05);At 8 weeks,10 weeks,and 12 weeks,the levels of FT3 and FT4 in the model group were significantly higher than that of the normal group by more than two times,and the difference was statistically significant(P<0.05).The levels of serum TSH in the model group were lower than those in the normal group at 4 weeks,6 weeks,8 weeks,10 weeks,and12 weeks,and the difference was statistically significant(P<0.05).The serum FT3,FT4,TPOAb,and TGAb levels of the rats in the high iodine water group were significantly higher than those in the non-iodine water group at the 4th week after EAT modeling.The TSH level was significantly lower than the non-iodine water group,and the difference was statistically significant(P<0.05).2.Changes in thyroid weight index:The thyroid weight index in the model group continued to increase.At the 4thweek,the thyroid weight index of the model group was higher than that of the normal group,but the difference was not statistically significant(P>0.05).At 6th,8th,10 th,and 12 th week,the thyroid weight index of the model group was significantly higher than that of the normal group,and the difference was statistically significant(P<0.05);The thyroid mass index of rats in the iodine group was significantly higher than that in the non-iodine group at 4weeks after EAT modeling(P<0.05).3.Liver stagnation and spleen deficiency related indexes: Compared with normal group rats,the total exercise distance of 5 min and the number of penetrating cells,weight,food intake,and gastric emptying rate in the model group were significantly smaller than those in thenormal group,and the difference was statistically significant(P<0.05).The fecal water content was significantly larger than that in the normal group,and the difference was statistically significant(P<0.05).Conclusion:1.Immune-mediated + high iodine-water induced combined chronic restraint stress +excessive fatigue + diet loss method is successfully established at the 8th week of modeling.2.During EAT modeling,subclinical hyperthyroidism occurr at 4 weeks and clinical hyperthyroidism occur at 8 weeks.3.Rats that continued to be fed high iodine for 4 weeks after modeling have worsened thyroid function compared to rats that did not continue to be fed high iodine.