抗血管紧张素Ⅱ1型受体抗体阳性孕鼠模型的制备

Pregnancy in the rat with positive anti-angiotensin Ⅱtype 1 receptor antibody： a model for investigating the preeclampsia

目的制备抗血管紧张素Ⅱ1型受体（AT1R）抗体阳性的孕鼠模型，为先兆子痫疾病的自身免疫机制研究提供重要工具。方法以合成的人AT1R细胞外第二环肽段（AT1R—ECⅡ）为抗原主动免疫雌性Wistar大鼠，待雌鼠体内抗AT1R抗体达高峰后，将其与正常雄鼠（未免疫）交配，从而建立抗AT1R抗体阳性的孕鼠模型。用SA—ELISA法检测孕鼠妊娠中期血清中抗AT1R抗体的水平、免疫球蛋白类型及亚类。结果免疫雌鼠体内抗AT，R抗体滴度在4周时明显升高，8周时达高峰（A值为2．89±0．21，同期对照组A值为0．44±0．06，P〈0．01）；与正常雄鼠交配怀孕后14d时，免疫孕鼠血清中的抗AT1R抗体仍维持高滴度。该抗体属于IgG类免疫球蛋白，而非IgM及IgA类，在大鼠IgC的4个亚型（IgG1、IgG2a、IgG2b和IgG2c）中，该血清抗体主要属于IgG2b亚型（A值为0．32±0．04，同期对照组A值为0．08±0．01，P〈0．01），尚有极少部分属于IgG2a亚型（A值为0．10±0．01，同期对照组A值为0．07＋0．01，P〈0．05）。结论用主动免疫法可使孕鼠体内产生高滴度的抗AT，R抗体，且该抗体的亚型与先兆子痫患者体内的AT1受体自身抗体（AT1-AA）具有良好一致性，所以该造模方法可以作为从免疫学角度研究先兆子痫的一种工具。

Objective This study was designed to build a pregnant model in anti-angiotensin Ⅱ 1 receptor （AT1R）antibody-positive rat for studying the autoimmune mechanisms of preeclampsia. Methods Adult female Wistar rats were actively immunized with the synthetic peptide corresponding to the sequences for the second extracellular loop of AT1R （AT1R- ECⅡ）. When the titer of anti-AT1R antibody reached a peak, the immunized female rats were mated with health male rats to establish a long-term antibody-positive pregnant rat models. The titers, types and subtypes of anti-AT1R antibody in the medium-term of pregnancy were detected by SA- ELISA. Results The titers of serum anti-AT1R antibody in immunized group were increased at 4th week and attained a peak value at 8th week as compared with the control group at the same time point （2.89±0.21 vs 0.44± 0.06, P〈0.01 ）. The titer of antibody still maintains a high level at 14th day after mating with health male rats. It was shown that anti-AT1R antibody was IgG type immunoglobulin. Meanwhile, the antibody was mainly determined as IgG2b subtype （A 0.32±0.04 vs A 0.08±0.01 of control group at the same time point,P〈0.01）, and a few parts belonged to 1gG2a subtype （A 0.10±0.01 vs A 0.07±0.01 of control group in the same time point, P〈0.05）. Conclusion The anti-AT1R antibodies in pregnant rats had high similarities with the AT1 receptor autoantibodies （AT1-AA）in preeclamptic patients. Therefore, the rat model would be a powerful tool for investigation of the immune mechanism of preeclampsia.