Pancaldi S, Dall'Olio G, Poli F, Fasulo M P
Institute of Botany, University of Ferrara, Italy.
Microbios. 1994;80(322):55-61.
Blastospores of Candida albicans were exposed in vitro to fluconazole, a bis-triazole which inhibits ergosterol biosynthesis in fungi by interfering with the cytochrome P-450 dependent 14 alpha-demethylase. Electron microscope examination revealed that a low dose (3 micrograms/ml), short treatment (1-3 h) with this compound greatly stimulated autophagic activity not accompanied by alterations of the cell organelles. Only rarely, wall thickenings and some damage to the membrane system, except for the plasma membrane, was noted. This unusual phenomenon suggests that in the presence of fluconazole, due to the depletion of ergosterol and the consequent accumulation of 14 alpha-methylsterols, changes are induced in the properties of the tonoplast. It seems that in the presence of the molecule the membrane is not able to distinguish what is to be degraded from what is still useful for intracellular metabolism with the consequent disintegration of cell compartmentation. Fluconazole may be useful for indicating the mechanism for controlling lytic activity and the homeostatic role of the vacuole in yeasts.
白色念珠菌的芽生孢子在体外暴露于氟康唑，这是一种双三唑类药物，它通过干扰细胞色素P - 450依赖的14α-脱甲基酶来抑制真菌中麦角固醇的生物合成。电子显微镜检查显示，用该化合物进行低剂量（3微克/毫升）、短时间处理（1 - 3小时）可极大地刺激自噬活性，且细胞器无变化。仅偶尔观察到除质膜外的细胞壁增厚和膜系统的一些损伤。这种不寻常的现象表明，在氟康唑存在下，由于麦角固醇的消耗以及随之而来的14α-甲基固醇的积累，液泡膜的性质发生了变化。似乎在该分子存在的情况下，膜无法区分哪些是要降解的，哪些对细胞内代谢仍有用，从而导致细胞区室化的解体。氟康唑可能有助于揭示控制酵母中溶解活性的机制以及液泡的稳态作用。
