Kattenbach W M, Pimenta P F, de Souza W, Pinto da Silva P
Departamento de Parasitologia e Biofísica Celular, Instituto de Biofísica Carlos Chagas Filho, Brazil.
Parasitol Res. 1991;77(8):651-8. doi: 10.1007/BF00928678.
The freeze-fracture technique was used to study the structural organization of the membranes of trophozoites of the protozoon Giardia duodenalis. No special array of intramembranous particles was observed in the membrane lining the protozoon body or the flagella. A large globular protuberance located in the ventral region displayed several small circular indentations similar to those seen in the dorsal region. These also occurred on the parasite surface as revealed in fracture-flip replicas. A large number of vesicles were observed below the plasma membrane; they corresponded to an acidic compartment as indicated by fluorescence microscopy of acridine orange-stained cells and contained acid phosphatase as indicated by cytochemistry. In addition, gold-labeled macromolecules (albumin, peroxidase, transferrin, and low-density lipoprotein) accumulated in the vesicles. These observations suggest that the peripheral vesicles of trophozoites are part of the endosomal-lysosomal system of G. duodenalis.
采用冷冻断裂技术研究了原生动物十二指肠贾第虫滋养体膜的结构组织。在原生动物体或鞭毛内衬的膜中未观察到特殊排列的膜内颗粒。位于腹侧区域的一个大的球状突起显示出几个小的圆形凹陷，类似于在背侧区域看到的凹陷。在断裂翻转复制品中也显示这些凹陷出现在寄生虫表面。在质膜下方观察到大量囊泡；吖啶橙染色细胞的荧光显微镜检查表明它们对应于一个酸性区室，细胞化学显示它们含有酸性磷酸酶。此外，金标记的大分子（白蛋白、过氧化物酶、转铁蛋白和低密度脂蛋白）在囊泡中积累。这些观察结果表明，滋养体的外周囊泡是十二指肠贾第虫内体-溶酶体系统的一部分。
