Dependence of Plasmodium falciparum in vitro growth on the cation permeability of the human host erythrocyte
Dependence of Plasmodium falciparum in vitro growth on the cation permeability of the human host erythrocyte
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DOI：
10.1159/000075122
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发表时间：
2003-01-01
影响因子：
--
通讯作者：
Lang, F
中科院分区：
文献类型：
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作者：
Brand, VB;Sandu, CD;Lang, F
恶性疟原虫（Plasmodium falciparum）的红细胞内生长诱导宿主细胞膜上的Ca ~（2+）可透过的非选择性阳离子电导，这种电导可被乙基异丙基氨氯吡咪（EIPA）抑制，并被宿主细胞液中的Na ~+交换K ~+所抑制。本研究旨在阐明电解质交换的功能意义。全细胞膜片钳实验证实了恶性疟原虫诱导的阳离子通道的Ca ~（2+）通透性和EIPA敏感性。在进一步的实验中，在不同的测试介质中，在体外生长环阶段同步的寄生虫48小时。分别用DNA染料Syto 16和膜联蛋白V染色，用流式细胞仪分析测定疟原虫感染和磷脂酰丝氨酸暴露红细胞的百分比。用葡萄糖酸钠替代培养基中的NaCl 8 h对感染细胞的增加没有显著影响，但用KCl、NMDG-Cl或棉子糖替代NaCl则显著减弱。在约25 mM Na+下观察到半数最大生长。EIPA进一步抑制感染细胞的增加（IC_（50
Intraerythrocyte growth of the malaria parasite Plasmodium falciparum induces a Ca2+-permeable unselective cation conductance in the host cell membrane which is inhibited by ethylisopropyl-amiloride (EIPA) and is paralleled by an exchange of K+ by Na+ in the host cytosol. The present study has been,performed to elucidate the functional significance of the electrolyte exchange. Whole-cell patch-clamp experiments confirmed the Ca2+ permeability and EIPA sensitivity of the Plasmodium falciparum induced cation channel. In further experiments, ring stage-synchronized parasites were grown in vitro for 48 h in different test media. Percentage of Plasmodium-infected and phosphatidylserine-exposing erythrocytes was measured with FACS analysis by staining with the DNA-dye Syto16 and annexin V,respectively. The increase of infected cells was not significantly affected by an 8 h replacement of NaCl in the culture medium with Na-gluconate but was significantly blunted by replacent of NaCl with KCl, NMDG-Cl or raffinose. Half maximal growth was observed at about 25 mM Na+. The increase of infected cells was further inhibited by EIPA (IC50