Chen P, Tu Y, Wang F, Li F, Yang L
Department of Parasitology, Capital University of Medical Sciences, Beijing 100054.
Zhongguo Ji Sheng Chong Xue Yu Ji Sheng Chong Bing Za Zhi. 1998;16(6):421-4.
To observe the effect of dihydro qinghaosu (DQHS) on the development of Plasmodium yoelii yoelii in Anopheles stephensi and to explore the possibility of whether DQHS has preventive effect against malaria.
Plasmodium yoelii yoelii-infected mice that had been administered with a single dose of different dosages (60 mg/kg, 120 mg/kg, 180 mg/kg and 240 mg/kg) of DQHS were exposed to mosquitoes to suck blood. The development of malaria parasites in the mosquitoes of the control group and the treated group were observed by light microscopy (LM) and transmission electron microscopy (TEM).
DQHS exhibited certain inhibitory effect on the infectivity of gametocyte. The degree of inhibition was related to the developmental stages of gametocyte and the drug dosage. Immature gametocytes were more sensitive to DQHS than the mature gametocytes. With the increases in dosage, the positive rate and the density of oocyst and sporozoite decreased. However, the difference in the density of sporozoite between 180 mg/kg and 240 mg/kg treated groups was insignificant. TEM result showed damage of the membrane system and vacuolation in the cytoplasm of the oocysts (12-13 d) on mosquito midgut of 60 mg/kg 16 h treated group. The oocysts in the mosquitoes continued to develop after treated with 120 mg/kg of DQHS for 16 h on 3-day-instar. There was no significant difference (P > 0.05) in the density of oocyst and sporozoite between the control group and the treated group.
DQHS can affect the infectivity of gametocyte and decrease the malaria transmission but cannot inhibit the sorogonic stage directly.
观察双氢青蒿素（DQHS）对约氏疟原虫在斯氏按蚊体内发育的影响，探讨其对疟疾是否具有预防作用。
将感染约氏疟原虫的小鼠分别给予不同剂量（60mg/kg、120mg/kg、180mg/kg和240mg/kg）的单剂量双氢青蒿素，然后让蚊子叮咬吸血。通过光学显微镜（LM）和透射电子显微镜（TEM）观察对照组和处理组蚊子体内疟原虫的发育情况。
双氢青蒿素对配子体的感染力有一定抑制作用。抑制程度与配子体发育阶段及药物剂量有关。未成熟配子体比成熟配子体对双氢青蒿素更敏感。随着剂量增加，卵囊和子孢子的阳性率及密度降低。然而，180mg/kg和240mg/kg处理组子孢子密度差异不显著。透射电镜结果显示，60mg/kg处理16小时组蚊子中肠12 - 13天卵囊的膜系统受损且细胞质出现空泡化。用120mg/kg双氢青蒿素处理3龄期蚊子16小时后，卵囊继续发育。对照组和处理组卵囊及子孢子密度无显著差异（P > 0.05）。
双氢青蒿素可影响配子体感染力，降低疟疾传播，但不能直接抑制孢子增殖阶段。
