青蒿素对体外培养人恶性疟原虫不同生长期的选择性作用

应用同步化程度较高的体外培养人恶性疟原虫进行试验，测定了不同生长期的红内期疟原虫对青蒿素的药物敏感性。在疟原虫不同生长期分别用药处理且药物作用时间不同的条件下，通过比较^3H-次黄嘌呤掺入疟原虫核酸中放射量的变化，测量青蒿素的抗疟作用。试验中发现，体外培养人恶性疟原虫的滋养体期对青蒿素的作用最敏感，早期环状体对青蒿素最不敏感。晚期环状体和裂殖体期疟原虫对青蒿素的敏感性介于上述二者之间。本试验结果表明，青蒿素的这种对红内期疟原虫不同生长期的选择性作用有与其干扰疟原虫的蛋白代谢有关。

Selective Effect of Qinghaosu on Different Stages of Plasmodium falciparum in Vitro

Using highly synchronous cultures of Plasmodium falciparum in vitro,the susceptibi- lity of the different stages of the intraerythrocytic parasites to Qinghaosu (QHS) was assessed.The anti- parasitic effect of QHS was measured by comparing the changes of irradiation of~3 H-hypoxanthine in- corporated into the nucleic acids of parasites exposed to various concentrations of QHS at different stages of growth.It was found that the trophozoite stage of the parasite was the most sensitive to QHS, whereas the early ring stage was the least sensitive,and the sensitivities of the late ring and schizont stages fell between those of the early ring and trophozoite stages.The results revealed the correlation of stage-dependent effects of QHS with the blockade of the protein metabolism of the parasite.