伯氏疟原虫感染红细胞中的游离氨基酸和多胺生成的研究

FREE AMINO ACID AND SYNTHESIS OF POLYAMINES UN PLASMODIUM-BERGHEI-INECTED RBC

伯氏疟原虫氯喹敏感株(CS)和抗氯喹株(CR)感染红细胞中的游离氨基酸量和鸟氨酸脱羧酶活力均相接近,用氯喹10mg/kg im两个株的感染小鼠,20h后对游离氨基酸无抑制作用.氯喹剂量为5mg/kg时,抑制CS和CR感染红细胞的鸟氨酸脱羧酶活力为79.6和55.7％。 CS和CR感染红细胞中的精脒量为139±27和528±140nmol/10~9感染红细胞。环亮氨酸剂量为80mg/kg时,能抑制CS和CR感染红细胞的精脒生成,其抑制率分别为44和57％,加喂甲硫氨酸(100mg/kg)后,精脒量分别上升至294和657nmol/10~9感染红细胞。但是与两者仍有一定差距,故认为在S-腺苷甲硫氨酸合成酶及其后的代谢环节仍有差异.

The contents of free amino acids and the activity of ornithine decarboxylase in infected RBC of chloroquine-sensitive strain of Plasmodium berghei(CS) were similar to those in chloroquine-resistant strain (CR). After treatment with chloroquine (10mp/kg im) no effect on the formation of free amino acids was found after 20th, but chloroquine (5mg/kg im) inhibited the enzymatic activity of the CS RBC by 79.6% whereas that of the CR by 55.7%.The contents of spermidine in CS and CR infected RBC were found to be 139 ±27 and 528±140 nmol/109 infected respectively. Cycloleucine inhibited the formation of spermidine by 44% in CS and 57% in CR groups, while co-administration of methionine (100mg/kg) with cycloleucine (80mg/kg) could reverse the inhibitory effect and raise the contants of spermidine to 294 ± 56 and 657±129 nmol/109 infected RBC in CS and CR groups respectively. This indicates that methionine had significant effect on the formation of spsrmidine in CS strain, but there was still a remarkable difference, when compared with CR strain. It is suggested that the activities of S-adenosyl-methionine synthetase and other enzymes involved in polyamine formation might be the causal factors.