PCNA在PTU致大鼠甲状腺增生效应中的表达规律

The Expression Rule of Proliferating Cell Nuclear Antigen in Rat Thyroid of Hyperplasia Induced by Propylthiouracil

目的分析增殖细胞核抗原(PCNA)在甲状腺素干扰物丙硫氧嘧啶(propylthiouracil,PTU)致大鼠甲状腺增生效应中的表达规律。方法雄性SD成年大鼠,PTU(5.0mg/kg.d)灌胃染毒,分别设染毒3d、染毒6d、染毒9d、染毒12d组和对照组,每组5只大鼠,在染毒期满后处死动物,取甲状腺组织进行PCNA的免疫组化染色和RT-PCR检测。结果与对照组相比,免疫组化染色和RT-PCR均检测到PCNA在染毒3d组明显增高(P<0.05),染毒6d组达到最高,染毒9d、染毒12d组呈现下降的趋势。结论PCNA在甲状腺增生中存在先增高后降低的表达规律,提示甲状腺激素干扰物甄别试验的动物试验期可明显缩短为6d。

Objective To study the expression rule of proliferating cell nuclear antigen （PCNA） in thyroid when the hyperplasia of male rat thyroid is induced by propylthiouracil （PTU）. Methdos PTU was administered to rats by gavage at a dose of 5.0 mg/kg B. W for 0,3,6,9 and 12 days respectively. All animals were sacrificed after the last dosage, and the expression of PCNA in thyroid was detected by immunohistochemistry and RT-PCR. Results Compared with the control group, the PCNA level in the thyroid of rats given PTU for 3 days significantly increased（P〈0. 05） ,and reached the highest expression when it was 6 days, but then when it was 9 days and 12 days, the PCNA expression showed a descending tendency. Conclusion PCNA has a expression rule in hyperplastic thyroid： expression increase first but then decrease. This rule confirms the histological change of thyroid in earlier stage. The experimental time of assessment test to thyroid hormone disruptors will be shortened to six days.