Nanda N
Malaria Research Center, Delhi, India.
Indian J Malariol. 1990 Jun;27(2):65-78.
Fine structural analysis of the trophic and sexual stages of Plasmodium vivax obtained from naturally infected humans revealed that in general, the structural features as well as certain specialized functions such as haemoglobin ingestion and utilization etc., are similar to those described for other malaria parasites. Young trophozoite is characterised by less condense cytoplasm with scattering of free ribosomes and minimum amount of endoplasmic reticulum. The trophozoite grows by feeding on the host cell cytoplasm with its cytostome. Older trophozoite gets considerably enlarged and its cytoplasm appears coarsely granular due to an increase in endoplasmic reticulum and ribosomal content. The two sexual forms, the macro- and microgametocyte, can be distinguished on the basis of their fine structure. The macrogametocyte has high ribosomal density and more osmiophilic bodies than microgametocyte and possesses a compact dense nucleus with nucleolus-like region whereas the microgametocyte has large diffuse nucleus without nucleolus. Caveola-vesicle complexes and cytoplasmic clefts are observed in all erythrocytes infected with P. vivax and the incidence of these host cell alterations increases as the intraerythrocytic parasite matures.
对从自然感染人类体内获取的间日疟原虫营养期和有性期进行的超微结构分析表明，总体而言，其结构特征以及某些特殊功能（如血红蛋白摄取和利用等）与其他疟原虫所描述的相似。年轻滋养体的特征是细胞质不太浓缩，有游离核糖体散布，内质网含量最少。滋养体通过其胞口摄取宿主细胞细胞质而生长。较老的滋养体明显增大，由于内质网和核糖体含量增加，其细胞质显得粗糙颗粒状。两种有性形态，即大配子体和小配子体，可以根据其精细结构加以区分。大配子体的核糖体密度高，嗜锇体比小配子体多，具有一个带有核仁样区域的紧密致密核，而小配子体有一个无核仁的大而弥散的核。在所有感染间日疟原虫的红细胞中都观察到小窝-囊泡复合体和细胞质裂隙，随着红细胞内寄生虫的成熟，这些宿主细胞改变的发生率增加。
