ION CONCENTRATIONS IN TRYPANOSOMA CRUZI

克氏锥虫中的离子浓度

• 批准号: 6112709
• 负责人: R LEAPMAN
• 金额: --
• 依托单位: OFFICE OF THE DIRECTOR, NATIONAL INSTITUTES OF HEALTH
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/6112709
• 关键词: Trypanosoma cruzi; acidity /alkalinity; calcium metabolism; cell component structure /function; cryoscopy; ionomycin; iron metabolism; microorganism metabolism; organelles; sectioning; spectrometry; tissue /cell culture; vesicle /vacuole

The elemental content of different compartments of Trypanosoma cruzi epimastigotes has been measured by quick freezing, ultracryomicrotomy, x-ray microanalysis and compositional mapping in the scanning transmission electron microscope. Vacuoles identified by high electron-density contained large amounts of phosphorus, and the divalent cations, magnesium, calcium and zinc. No other compartment had appreciable calcium or zinc content. Iron was detected only in vacuoles distinct from the electron-dense vacuoles and other organelles. To determine the distribution of calcium-rich and iron-rich vacuoles within the trypanosomes, compositional maps were collected using electron energy loss spectrum-imaging. In this technique, spectra were analyzed at each pixel to obtain distributions of calcium and iron. Incubation of cells in culture medium with ionomycin plus nigericin led to factor of 2-3 increase in potassium in the electron-dense vacuoles and in the iron-rich vacuoles. This finding indicated the acidic nature of the vacuoles and demonstrated that the electron-dense vacuoles correspond to the acidocalcisome, i.e., an acidic compartment rich in Ca2+, that has been characterized biochemically but has not been identified morphologically. The x-ray analysis and elemental mapping provide evidence that acidocalcisomes are organelles different from lysosomes or other organelles previously described in these parasites which are the agent causing Chagas' disease. This is a continuation of Intramural Research Project Z01-RR-10479-02 BEI.

不同舱室的元素含量 克氏锥虫外鞭毛体的快速测定 冷冻、冷冻切片、X射线微量分析和 扫描透射电子成分图 显微镜通过含有高电子密度来鉴定的微球 大量的磷和二价阳离子，镁， 钙和锌其他腔室无明显钙含量 或锌含量。铁只在与细胞核不同的液泡中被检测到。 电子致密的液泡和其他细胞器。确定 富钙和富铁空泡的分布 锥虫，组成图收集使用电子 能量损失谱成像在这项技术中，光谱是 在每个像素处分析以获得钙和铁的分布。 在含有离子霉素和尼日利亚菌素的培养基中孵育细胞 导致2 - 3倍增加钾的电子致密 液泡和富含铁的液泡中。这一发现表明， 酸性性质的液泡，并证明， 电子致密的空泡对应于酸钙体，即，一个 富含Ca2+的酸性隔室，其特征在于 生物化学上，但尚未确定形态。的 X射线分析和元素图谱提供了证据， 酸钙体是不同于溶酶体或其他细胞器的细胞器。 这些寄生虫中先前描述的细胞器， 引起南美锥虫病的病原体这是一个延续Intramural 研究项目Z01-RR-10479 - 02 BEI。