初步探讨过敏性紫癜兔模型的构建

Preliminary study to establish a rabbit model of allergic purpura

目的通过构建过敏性紫癜动物模型,为该病治疗方法的评价和新药研发提供可能。方法通过对日本大耳白兔热性药物的喂饮、腹腔注射卵白蛋白和弗氏完全佐剂生理盐水的混合液,持续抗原刺激后,耳缘静脉和背部皮内注射卵白蛋白生理盐水,激发过敏反应来构建过敏性紫癜模型。实验过程中分别进行一般症状观察;平均每天饮食,饮水量、体温、血常规、尿常规、便潜血等测量;皮肤、肾脏等脏器病理检测,并与人类疾病患者症状、实验室检查及病理改变相比较。结果与对照组相比,模型组兔表现为皮肤瘀斑;每天进食减少、饮水增多(P<0.01),体温升高(P<0.05);血WBC增多(P<0.01),RBC减少(P<0.01),HGB、MCHC均降低(P<0.01),NEU、NEU%、EOS、EOS%均升高(P<0.01);67%尿蛋白、尿红细胞阳性,70%便潜血阳性;病理表现为皮下血管扩张充血、出血,真皮水肿,炎细胞浸润;肾小球局灶性慢性肾炎,囊腔蛋白渗出,血管扩张充血,系膜基质增多,系膜增厚,红细胞管型,炎细胞浸润等;关节腔淤血,结缔组织坏死,炎细胞浸润等;皮肤、肾IgA免疫球蛋白大量沉积等;胃黏膜出血,坏死脱落;小肠绒毛血管扩张充血,上皮细胞脱落;肺淤血,肥大细胞似有脱颗粒现象;肝灶性炎细胞浸润等,这些改变与人过敏性紫癜患者病变基本相似。结论大耳白兔通过热性药物的喂饮,连续抗原刺激,静脉和皮内抗原冲击后,其症状、病理改变和实验室检查结果与人类过敏性紫癜病变基本相似,有望构建良好的过敏性紫癜兔模型。

Objective To establish a rabbit model of allergic purpura, and to provide a helpful measure for evaluation of the treatment and drug development for this disease. Methods Twenty-four 1.5 month-old Japanese white ear rabbits （male： female = 1 ： 1 ） were used in this study. The rabbit models were generated by oral administration of ＂thermal＂ drugs （traditional Chinese medicine）, and intraperitoneal injection of mixture of ovalbumin, Freund＇s complete adjuvant and saline. Then ovalbumin saline was intravenously injected into the ear marginal vein and intradermally injected into the skin on the back to stimulate allergic reactions. The rabbits in the control group received equal amount of normal saline in the same way. During the experimental process, several evaluations were performed ： observation of general symptoms, recording the average intake of daily diet and drinking water, body temperature, routine blood test （RBT） , routine urine test （RUT） , feces occult blood （FOB） test, and pathological examination of skin, kidney and some other organs was performed. All the data of laboratory tests, histopathology and symptoms of the rabbit models were compared with those of clin- ical patients. Results Compared with the control group, the rabbits of model group showed skin ecchymosis, less eating and more drinking （ P 〈 0. O1 ） , elevated temperature （ P 〈 0.05 ） , increased WBC and decreased RBC （ P 〈 0. 01 ） , reduced content of HGB and MCHC （P 〈 0.01 ） and increased NEU, NEU% , EOS, EOS% （P 〈 0. 01 ）. The urine protein （PRO） and urine erythrocytes were positive in 67% of the model rabbits, and feces occult blood （FOB） in 70% of the model rabbits. Pathological examination revealed subcutaneous vascular dilatation and congestion, hemorrhage, dermal edema, and inflammatory cell infiltration; focal chronic glomerulonephritis, glomerular sac protein exudation, vascular dilatation and congestion, increased mesangial matrix, mesangial thickening, erythrocyte cast, and inflammatory cell infiltration; blood extravasation, connective tissue necrosis and inflammatory cell infiltration in the joint synovial tissue; extensive IgA deposit in the skin and renal tissues; gastric mucosal hemorrhage, necrosis and exfoliation; vascular dilatation, congestion,and shedding of epithelial cells in the small intestinal villi; lung congestion and mast cells degranulation; and focal inflammatory cell infiltration in the liver tissue, etc. The above findings were quite similar to those in clinical patients with allergic purpura. Conclusions The rabbits after oral administration of ＂thermal＂ drugs, continuous antigenic stimulation, and intravenous and intradermal antigen impact, show symptoms, pathology and laboratory test results of allergic purpura, quite similar to the changes in patients with allergic purpura. It is promising to establish appropriate animal models of allergic purpura by this method to serve further studies in future.