【摘要】 目的观察组胺H2 受体抑制剂西米替丁对大白鼠抵抗华支睾吸虫再感染的拮抗作用 ,探讨大白鼠抵抗华支睾吸虫再发生感染的可能机制。方法30只SD(Sprague-Dawley)系雄性大白鼠分成5个实验组 ,A、B组分别为初感染和再感染对照组 ;C组为再感染组 ,不给任何药物 ;D组为强的松龙处理再感染组 ,从再感染前1周起每周肌注强的松龙10mg/kg,共5次 ;E组为西米替丁处理再感染组 ,从再感染前1天起用西米替丁100mg/kg/d灌胃 ,共4周。初感染时每鼠接种囊蚴100个 ,感染后4周用吡喹酮100mg/kg连续灌胃治疗3天。再感染时每鼠接种囊蚴100个 ,每周采外周血进行嗜酸性粒细胞计数。4周后回收虫体计算回收率和保护率 ,并观察比较各组虫体发育情况。结果对照A、B组虫体回收率分别为60.7%和58.3 % ,虫体发育良好 ;C、D组和E组虫体回收率分别为4.3 % ,62.2 %和33.7% ;保护率分别为92.5% ,-13.3%和45.8 % ;C组虫体小 ,虫体及生殖系统发育明显受阻 ;D组虫体比对照组大 ,发育良好 ;E虫体发育界于C组与D组之间。结论大白鼠抵抗华支睾吸虫再感染表现为降低虫体回收率和抑制虫体发育 ,与强的松龙能完全消除这一保护作用不同 ,组胺H 2 受体抑制剂西米替丁只表现为部分拮抗作用。更多还原

【Abstract】 Object To observe the effect of histamine H 2 receptor inhibitor cimetidine on the resistance to reinfection with Clonorchis sinensis in rats for probing the mechanism of the resistance.Methods Thirty SD male rats were divided into5groups.Group A and B represented primary and reinfection control,respectively.Group C was reinfected group with no immunosuppression.Group D and E were reinfected group with administration of methylprednisolone10mg/kg/wfor5times and cimetidine100mg/kg/d for4weeks,respectively.Each rat was primarily infected with100metacercariae and4weeks after and infection treated with100mg/kg of praziquentel for3days.The cured rat was challenged with another100metacercariae in4weeks post-treatment in reinfection and the kinetics of eosinophils in peripheral blood was checked weekly.Rats were scarified in4weeks post-in-fection for comparing the worm recovery rates and worm development among5groups.Results Worm recovery rate of Group A and B was60.7%and58.3%,respectively.The worms in these two groups fully developed.The worm recovery rate in Group C,D and E was3%,62.2%and33.7%,respectively.And the protective rate in each group was92.5%,-13.3%and45.8%,respectively.The worm size of Group C was very small and the development of reproductive organs was inhibited.Worms from group D were larger than those from control groups and the organs developed very well.The worm development in Group E was in the middle level among the rein-fection groups.Conclusion After clearance of the primary infection rats developed very strong resistance to rein-fection with Clonorchis sinensis,which was characterized as low worm recovery rate and retarded development in reinfection.Unlike methylprednisolone completely impairing the resistance cimetidine partly antagonized the resis-tance and the mechanism of this phenomenon need to be clarified further.更多还原