弓形虫RH株在实验感染小鼠体内分布的研究

STUDY ON THE DISTRIBUTION OF RH STRAIN TOXOPLASMA GONDII IN EXPERIMENTAL INFECTED MICE

目的 以间接免疫酶法观察弓形虫 (RH株 )感染时的急性期病变特点及虫体在主要脏器的动态分布 ,以期为弓形虫病的病理诊断提供依据 ,并对弓形虫致病机理加深理解。方法 用弓形虫 RH株速殖子 10 3个经腹腔感染昆明小鼠 ,于感染后第 2、4、6和 8d,取肝、脾、肺和脑进行间接免疫酶染色。结果 虫体首先在肝脏内被发现 (第 2 d) ,其次是脾和肺 (第 4d) ,最后是脑 (第 8d)。感染早期 ,肝与脾边缘均可见虫体且较多 ;随时间延长 ,肝、脾与肺组织内部逐渐发现少量虫体 ,分布均匀 ;随病程延长 ,各脏器内虫体由少增多 ;脑内发现虫体最晚 ;小鼠体内虫体大量增殖 ,病变严重 ,最终死亡。结论 间接免疫酶染色方法可清楚显示弓形虫感染急性期的组织内弓形虫速殖子及抗原成份。小鼠多脏器被累及如肝、脾、肺和脑。间接免疫酶染色观察结果提示 ,经腹腔感染小鼠时 ,虫体播散途径为 :虫体首先直接侵入腹腔内的器官 ,再通过血液循环播散 。

Aim In order to observe the pathological features and the dynamic distribution of RH strain T.gondii in main organs of infected mice, using indirect immunoenzymatic technique. To provide pathological diagonsising reference of toxoplasmosis and increase to understand the pathologensis of Toxoplasmosis. Methods Mice were infected intraperitoneally with 10 3 tachyzoites of T.gondii RH strain,and the parasites were detected using indirect immunoenzymatic technique in the liver, spleen, lungs and brain at 2,4,6 and 8 days postinfection. Results The liver was the first organ parasitized at D2, followed by spleen and lungs at D4, the brain at D8. At the early phase of infection, parasites were found on the edge of the liver and spleen. A few parasites were detected within the liver, spleen and lungs with time being. But parasites increased progressively and distributed well during the whole phase. The brain was the last organ to be parasitized. Parasites multiplicated rapidly so that the mice were seriously ill and died. Conclusions The indirect immunoenzymatic technique can demonstrate tachyzoites and Toxoplasma antigen clearly in infected mice during acute stage. Many organs were infected such as liver,spleen,lungs and brain. The results suggest that the organs in the peritoneal cavity were infected directly by tachyzoites as IP infection, then the parasites disseminate through a blood way, and in the end, tachyzoites cross the blood-brain barries to reach the brain.