伯氏疟原虫氯喹抗性株红内期虫体的凋亡

目的：研究伯氏疟原虫（Plasmodium berghei)氯喹抗性（RC）株红内期虫体细胞危机状态的性质。方法：应用光学显微镜和透射电镜及基因组DNA琼脂糖电泳技术，观察感染伯氏疟原虫RC株或氯喹敏感（N）株ICR小鼠在原虫血症上升期和感染RC株小鼠自愈期虫体的显微及超微结构，以及基因组DNA琼脂糖电泳图谱。结果：在光镜下，原虫血症上升期的RC株和N株虫体结构无异常；而RC株感染小鼠自愈期虫体密度下降，大部分虫体固缩，周围呈空泡状。在电镜下，原虫血症上升期的RC株和N株红内期虫体胞膜结构完整，核位于一侧，胞质内可见各种细胞器，代谢窗明显。N株滋养体可见食物泡和疟色素。但RC株感染小鼠自愈期红内期虫体呈球形或椭圆形；胞膜完整，核固缩，胞质浓缩，线粒体和膜状结构消失，未见代谢窗结构。原虫血症上升期的RC株和N株红内期虫体基因组DNA电泳均为一条带，而RC株感染小鼠自愈期红内期虫体基因组DNA电泳呈典型的梯形条带。结论：伯氏疟原虫RC株红内期虫体危机状态的性质是凋亡。

Apoptosis of chloroquine-resistant strain of Plasmodium berghei at asexual stages

Objective: To investigate the feature of crisis at asexual stages of chloroqine resistant strain (RC) of Plasmodium berghei . Methods: By means of optical microscope,transmission electron microscope and agarose electrophoresis, microscopic and ultramicroscopic architectures, and genomic DNA electrophoresis at asexual stages of the RC and chloroquine sensitive (N) strains of P. berghei with rising parasitemia and the RC strain of the parasite with declining parasitemia were observed in ICR mice. Results: Under microscope, different developmental stages asexual parasites with normal forms were found in blood smears from the mice infected by the N and RC strains with rising parasitemia, whereas there were a few of the asexual parasites most of which were contracted and vacuolated from the mice recovered from infection by the RC strain. Using electron microscope, intact cytoplasm membranes of the parasites paralleling with parasitophrous membrane of erythrocytes, nuclear laterad, obvious metabilic window and mitochondrions, ribosomes, endoplasmic reticulum in cytoplasm were recognized in erythrocytic stages of the RC and N strains with rising parasitemia. There were rhoptries in merozoites and food vacuoles in trophozoites of the N strain. Erythrocytic parasites of the RC strain from recovered mice with declining parasitemia were spherical or elliptical, with intact cytoplasm membrane, contracted nuclei and concentrated cytoplasm, without mitochondrion membranaceous structure and metabolic windows. The genomic DNA electrophoretogram of the RC strain parasites in the recovered mice showed a ladder pattern, which differed evidently from the parasites of the RC strain with rising parasitemia and the N strain which showed a single band. Conclusion: It is confirmed that crisis form of asexual stages of the RC strain is apoptosis.