扁桃酸对感染小鼠腹水中弓形虫速殖子超微结构的影响

为探讨扁桃酸的杀虫机制，应用透射电镜观察扁桃酸对感染弓形虫小鼠治疗24h、72h和死亡后弓形虫速殖子的超微结构变化，扁桃酸20mg/ml，0.25ml/只，2次/d经口灌服和经尾静脉注射途径给药，同时用乙胺嘧啶5mg/ml，0.25ml/只，1次/d作为药物对照。结果显示，扁桃酸在不同时期对弓形虫的超微结构均有破坏作用，且随药物作用时间延长，其杀虫作用增强。扁桃酸主要破坏虫体的细胞膜、细胞质中的线粒体、棒状体和内质网等，致密颗粒减少或消失。虽然乙胺嘧啶较扁桃酸对虫体的破坏程度稍强，但乙胺嘧啶在杀灭虫体的同时也破坏了腹水中正常细胞，而扁桃酸对正常细胞几乎无损伤。结果表明，扁桃酸的杀虫机制主要是破坏虫体细胞膜、细胞器和染色质，从而破坏了虫体赖以生存的理化环境和物质能量的代谢，破坏了虫体的遗传物质和遗传信息，抑制虫体的增殖。扁桃酸是高效低毒的抗弓形虫药物。

EFFECT OF MANDELIC ACID ON THE MICROSTRUCTURE OF TOXOPLASMA GONDII TACHYZOITE IN THE ASCITES OF INFECTED MICE

The microstructure changes of the Mandelic acid treated(24 h,72 h) and dead Toxoplasma gondii tachyzoite in vitro were observed with transmission electronic microscope to study its mechanism. Mandelic acid(20 mg/ml, twice daily) was administered by mouth or intravenous injection, and pyrimethamine(5 mg/ml, once daily) was used as the control. The results showed that Mandelic acid destroyed the microstructure of T. gondii after the different time of administration and the effect augmented with the prolongation of action time of Mandelic acid. Mandelic acid destroyed the cellular membrane, mitochondrial rhophy and endoplastic reticulum in cellular cytoplasm etc., and the number of dense granules also decreased or disappeared. Pyrimethamine showed stronger action than Mandelic acid, but pyrimethamine also destroyed the normal cells in the ascites as it killed the parasite. Mandelic acid hardly produced injury on the normal cells. The results suggest that the main action mechanism of Mandelic acid is destruction of the cellular membrane, cellular organs and chromatin to lead to the change of physical and chemical environment and energy metabolism and the destroy of hereditary substance in the parasite, then reproduction of T. gondii is inhibited. Mandelic acid is a high potency and low toxic agents against T. gondii .