甲状腺全切+L-T_(4)皮下注射建立孕期亚临床甲减大鼠模型及稳定性研究

Establishment of a subclinical hypothyroidism rat model during pregnancy by total thyroidectomy and subcutaneous injection of L-T_(4) and its stability evaluation

目的探讨采用甲状腺全切+L-T_(4)皮下注射方法建立孕期亚临床甲状腺功能减退症(SCH)大鼠模型及模型稳定性评价。方法选取26只体重180~200 g雌性SD大鼠作为研究对象,将其随机分为对照组(10只)及模型组(16只)。对照组采用甲状腺全切术,模型组采取甲状腺全切+术后L-T_(4)1.0μg/(100 g·d)皮下注射。观察2组大鼠术后1个月、甲状腺全切+术后L-T_(4)10 d后、妊娠13 d 3个时间点促甲状腺激素(TSH)、游离甲状腺素(TT4)水平和体重情况。结果模型组大鼠术后1个月血清TSH水平高于对照组,差异有统计学意义(P<0.01)。甲状腺全切+L-T_(4)10 d后,模型组大鼠血清TSH水平高于对照组,差异有统计学意义(P<0.01)。妊娠13 d时,模型组大鼠血清TSH水平明显高于对照组,差异有统计学意义(P<0.01)。模型组大鼠术后1个月血清TT4水平小于对照组,差异有统计学意义(P<0.01)。甲状腺全切+L-T_(4)10 d后2组大鼠血清TT4水平比较,差异无统计学意义(P>0.05)。妊娠13 d时,2组大鼠TT4水平比较,差异无统计学意义(P>0.05)。2组大鼠术前体重比较,差异无统计学意义(P>0.05)。术后1个月、甲状腺全切+L-T_(4)10 d后,模型组大鼠体重明显低于对照组,差异有统计学意义(P<0.01)。妊娠13 d时,模型组大鼠体重明显低于对照组,差异有统计学意义(P<0.01)。2组大鼠平均产子数比较,差异无统计学意义(P>0.05)。结论采用甲状腺全切+L-T_(4)皮下注射可以成功建立孕期SCH大鼠模型,且稳定性良好。

Objective To explore the establishment of a subclinical hypothyroidism(SCH)rat model during pregnancy using total thyroidectomy and L-T_(4) 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 control 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-T_(4)1.0μg/(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-T_(4)10 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-T_(4)10 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-T_(4)10 d(P>0.05).At the 13th day of pregnancy,there was no statistically significant difference in TT4 levels between the two groups(P>0.05).There was no significant 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-T_(4) can successfully establish a SCH rat model during pregnancy,with good stability.