孕期亚临床甲减大鼠模型的建立

Establishment of pregnant rat models with subclinical hypothyroidism

目的建立可靠的孕期亚临床甲减大鼠动物模型。方法将60只成年雌性Wistar大鼠随机分为三组:1完全甲减组:手术完全切除甲状腺;2亚临床甲减组:手术完全切除甲状腺后,予L-T4微渗泵1.0μg/(100 g·d)浓度持续皮下泵入,自怀孕第15 d剂量改为1.05μg/(100 g·d);3正常对照组:行甲状腺假手术。各组大鼠在基础状态、孕前和怀孕后第10、13、17 d和分娩当天采血测定甲状腺功能。结果各组大鼠在基础状态时,血清TSH和TT4水平差异无统计学意义(P>0.05)。完全甲减组大鼠在孕前和整个怀孕过程中及分娩当天血清TSH水平始终明显高于亚临床甲减组和正常对照组(P均<0.01),血清TT4水平始终明显低于其他两组(P均<0.01)。亚临床甲减组大鼠在孕前和整个怀孕过程中及分娩当天血清TSH水平始终明显高于正常对照组(P均<0.05),血清TT4水平始终与正常对照组相当(P均>0.05)。结论应用手术完全切除甲状腺,再予微渗泵皮下持续输入合适剂量的L-T4可以成功建立孕期亚临床甲减大鼠模型。

Objective To establish the animal models of pregnant rats with subclinical hypothyroidism. Methods Sixty fe- male adult Wistar rats were randomly divided into 3 groups, overt hypothyroidism （OH） group （total removal of the rats＇ thy- roid）, subclinical hypothyroidism （SCH） group （after total removal of the rats＇ thyroid, levothyroxine was given to the rats by miniosmotic pumps at 1.0μg/ 100g-dand then at 1.05μg/100g. d from thd 15th gestational days） and normal control group （false thyroid surgery was carried out）. The serum samples were collected from all rats of the 3 groups at baseline, preconception, 10th, 13th and 17th gestational days and at delivery, and thyroid function was detected at all the time points. Results At baseline, no statistically significant differences were found in the serum levels of TSH and TI＇4 among the 3 groups （P 〉0.05）. After thyroid surgery, the serum levels of TSH from preconception to delivery were all significantly higher in the OH group than in the SCH group and the normal control group （all P〈0.01）, while the serum levels of TT4 were all significantly lower than thosee of the abovementioned two groups （all P 〈 0.01 ）. The serum levels of TSH from preconception to delivery were all significantly higher in the SCH group than in the normal control group （all P〈0.05）, while the serum levels of TT4 were all similar to those of the normal control group （all P 〉 0.05）. Conclusions Total removal of thyroid and optimal dose of levothyroxine infusion with miniosmotic pump can successfully establish the animal model of pregnant rat with subclinical hypothyroidism.