大鼠阴道炎模型的建立与评价

Establishment and evaluation of a rat model of vaginitis

目的建立大鼠阴道炎模型,为阴道炎治疗药物的开发与评价提供新模型。方法临床阴道加德纳菌、白色链球菌及B族链球菌患者阴道样品中分离和纯化阴道加德纳菌、白色链球菌及B族链球菌株。26只雌性大鼠上午分别给予苯甲酸雌二醇(20 mg/kg)和链霉素(每只10μg)预处理,下午大鼠阴道内接种混合菌株,另选10只雌性大鼠皮下注射苯甲酸雌二醇(20 mg/kg)作为正常组,每天1次,连续3 d。分组前采集阴道分泌物和阴道冲洗液观察大鼠阴道混合菌感染情况,选取感染成功20只大鼠按体重和菌株负荷量随机分为模型组和药物验证组(复方甲硝唑阴道栓每只54 mg,每天1次,连续5 d),每组10只动物。正常组和模型组经阴道给予等量的0.9%氯化钠注射液。末次给药后采集阴道灌洗液检测菌株负荷情况,并采集阴道分泌物进行阴道涂片、清洁度以及p H检查。取阴道组织经HE染色观察其病理组织学改变。结果模型组大鼠阴道壁变厚,复层扁平上皮细胞变性坏死脱落,固有层充血水肿明显,以中性粒细胞为主细胞,淋巴细胞和单核细胞炎细胞浸润,散在点状出血,乳突区成纤维细胞增生明显,网状纤维轻度增生。模型组阴道灌洗液混合菌数目、p H值及清洁度评分均显著大于正常组(P<0.01),且转阴率显著减少(P <0.01);复方甲硝唑阴道栓组能显著降低阴道灌洗液混合菌数目、p H值及清洁度评分,且增加阴道转阴率,同时能显著改善阴道组织病变程度。结论对大鼠进行雌激素和注射用硫酸链霉素预处理后,接种混合菌可成功建立大鼠混合性阴道炎模型,为女性生殖系统的药物筛选与评价提供有效的动物模型。

Objective A rat model of vaginitis was established to provide a model for developing and evaluating therapeutic drugs for vaginitis. Methods Gardnerella vaginalis,Streptococcus albus and Group B Streptococcus were isolated and purified from clinical vaginal samples. Twenty-six female rats were treated with 20 mg/kg estradiol benzoate and 10 μg/kg streptomycin in the morning,and mixed strains were inoculated into the vagina in the afternoon. Ten female rats serving as the control group were subcutaneously administered 20 mg/kg estradiol benzoate once daily for 3 days. Mixed bacterial infections in the vaginas of the rats were observed by collecting vaginal discharge and lavage fluid,then the rats were grouped according to body weight and strain load. Twenty rats were randomly divided into either the model group( 54 mg/day compound metronidazole vaginal suppository once daily for 5 days) or the drug validation group,with 10 animals per group. The control and model groups were injected vaginally with 0. 9% sodium chloride. After the last drug administration,the bacterial strain loads were detected via vaginal lavage,and the vaginal smears,cleanliness and p H were examined from the vaginal discharge. The vaginal tissue was performed to observe the histomorphological changes by HE staining. Results In the model group,the vaginal walls became thickened,the stratified squamous epithelial cells became denatured and necrotic,and the lamina propria became engorged and edematous. Neutrophils were the primary cells,and lymphocyte and monocyte infiltration occurred,with scattered punctiform hemorrhaging,obvious fibroblast proliferation in the mastoid region,and slight reticular fiber proliferation. The mixed bacterial numbers,p H values and cleanliness scores were significantly higher in the model group than in the normal group( P < 0. 01),and the negative conversion rate was significantly reduced( P < 0. 01). A compound metronidazole vaginal suppository significantly reduced the numbers of mixed bacteria,p H values and cleanliness scores;increased the negative rate for vaginal bacteria and significantly attenuated the degree of the vaginal lesions. Conclusions After pretreatment with estrogen and streptomycin sulfate injections,a rat model of mixed vaginitis was successfully established by inoculating mixed bacteria,thus providing an effective animal model for drug screening and evaluation of female reproductive system.