体外培养的伯氏疟原虫红外期超微结构及其药物敏感性观察

OBSERVATION OF ULTRASTRUCTURE AND DRUG SENSITIVITY OF IN VITRO CULTURED EXOERYTHROCYTIC FORM OF PLASMODIUM BERGHEI

用透射电镜观察体外培养的伯氏疟原虫红外期(Exoerythrocytic stage of Plasmodiumberghei;P.b.EE)的超微结构并测定了P.b.EE的体外药物敏感性。P.b.EE培养于单层宿主细胞内并原位固定和包埋,常规切片,观察。电镜图片显示体外培养的P.b.EE微细结构与Meis等描述的在大鼠体内发育的肝细胞内P.b.EE相似。虫体位于纳虫空泡中,虫体内可见核、线粒体、内质网、高尔基体等结构。将培养24h的P.b.EE在含一系列不同浓度的伯氨喹或氯喹的培养液中孵育48h,然后在光镜下检查,计算异常原虫的百分率。结果表明体外培养的P.b.EE对伯氨喹和氯喹的敏感性有显著差别,如在浓度1×10^(-5)mol/L时,异常原虫百分率分别为38.5±3.9％和5.7±1.9％。

The infrastructure of in vitro cultured exoerythrocytic stage (EE) of Plasmodium ber-ghei (P.b.)was observed under transmission electron microscope (TEM).The drug sensitivity of EE was also measured in vitro.The EE was cultured in monolayer host cell,fixed and embeded in situ.The ultrathin sections were prepared and examined by routine methods.The TEM pictures showed that the fine structure of in vitro cultured EE was similar with that of EE grown in rat hepatocytes in vivo,as described by Meis et al.The parasite was found within a parasitophorous vacuole,with nucleus,mitochondria,endoplasmic reticuia and Golgi apparatus were observed inside the parasite.After 24h cultivation,the EE was incubated for 48h in medium containing a serial concentrations of primaquine or chlo-roquine,then examined under light microscope.The percentage of abnormal parasites was calculated.The preliminary results showed that the sensitivity of cultured P.b.EE to primaquine and chloroquine was significantly different.At the same concentration of 1×10-5 mol/L,the percentage of abnormal parasites was 38.5±3.9% and 5.7±1.9% ,respectively These results demonstrated that the in vitro cultivation system of P.b.EE would have potential utility in antimalarial drug research.(Figs.1-6)