Establishment of a subclinical hypothyroidism rat model during pregnancy by total thyroidectomy and subcutaneous injection of L-T4 and its stability evaluation
Objective To explore the establishment of a subclinical hypothyroidism(SCH)rat model during pregnancy using total thyroidectomy and L-T4 subcutaneous injection method and evaluate the stability of the model.Methods A total of 26 female SD rats weighing 180-200 g were randomly divided into the con-trol group(n=10)and the model group(n=16).The control group was treated with total thyroidectomy,while the model group was treated with total thyroidectomy and postoperative subcutaneous injection of L-T41.0 μg/(100 g·d).The levels of TSH,TT4 and body weight were observed at three time points:one month after operation,after total thyroidectomy+L-T410 d after operation and 13 d after pregnancy.Results One month after operation,the serum TSH level of the rats in the model group was significantly higher than that of the control group,and the difference was statistically significant(P＜0.01).After total thyroidectomy+L-T410 d,the serum TSH level of the rates in the model group was higher than that in the control group,and the difference was statistically significant(P＜0.01).At the 13th day of pregnancy,the serum TSH level of the rates in the model group was significantly higher than that in the control group(P＜0.01).The serum TT4 level in the model group was lower than that in the control group one month after operation,and the difference was statistically significant(P＜0.01).There was no statistically significant difference in serum TT4 levels of the rats in two groups after total thyroidectomy+L-T410 d(P＞0.05).At the 13th day of pregnancy,there was no statistically significant difference in TT4 levels between the two groups(P＞O.05).There was no sig-nificant difference in preoperative weight between the two groups(P＞0.05).The weight of the model group was significantly lower than that of the control group after non-pregnancy surgery and drug administration,and the difference was statistically significant(P＜0.01).At 13th day of pregnancy,the weight of model group was significantly lower than that of control group,and the difference was statistically significant(P＜0.01).There was no significant difference in the average number of offspring between the two groups(P＞0.05).Conclusion The method of subcutaneous injection of L-T4 can successfully establish a SCH rat model during pregnancy,with good stability.
万方数据
