抗咯萘啶的伯氏疟原虫感染红细胞多胺量的测定

DETERMINATION OF POLYAMINES IN PYRONARIDINE SENSITIVE AND RESISTANT PLASMODIUM BERGHEI INFECTED ERYTHROCYTES

目的：了解疟原虫的多胺代谢与咯萘啶（ＰＮＤ）抗药性的关系。方法：感染伯氏疟原虫ＡＮＫＡ株（ＰＳ）和由该株培育的中抗ＰＮＤ品系（ＰＲＡ）及高抗ＰＮＤ品系（ＰＲＢ）的昆明株小鼠于腹腔接种（ｉｐ）后ｄ７取血，经薄层层析后用荧光分光光度法测定正常ＲＢＣ、ＰＳ、ＰＲＡ和ＰＲＢ感染ＲＢＣ的丁二胺（ＰＴＣ）、精脒（ＳＰＤ）和精胺（ＳＰＭ）量。另有感染ＰＳ和ＰＲＢ的小鼠于ｉｐ后ｄ６分别１次灌胃（ｉｇ）ＰＮＤ５ｍｇ／ｋｇ和１０ｍｇ／ｋｇ，ｄ７取血，按上述方法测定给药后感染ＲＢＣ的多胺量，并与不给药组比较。结果：ＰＳ感染ＲＢＣ的多胺量均明显高于未感染疟原虫的正常ＲＢＣ，而感染ＰＲＡ和ＰＲＢ的ＲＢＣ多胺量又显著高于ＰＳ感染ＲＢＣ，且多胺量的增高与抗性程度有关。经ＰＮＤ治疗后ＰＳ感染ＲＢＣ的ＳＰＤ和ＳＰＭ较未治疗组显著下降，而ＰＲＢ感染ＲＢＣ则未见明显变化。结论：伯氏疟原虫对ＰＮＤ的抗药性与其多胺代谢有关。

AIM: To understand the relationship between polyamine metbolism and pyronaridine resistance of malaria parasites.METHODS: Kunming strain mice weighing 18 g-22 g were inoculated intraperitoneally with Plasmodium berghei ANKA strain (pyronaridine sensitive, PS), and P. berghei ANKA strain low and high pyronaridine resistant lines(PRA and PRB), respectively. Seven days after inoculation,blood samples were collected and WBC in the blood were removed by the method of chromatography using SE cellulose and Sephadex G25 (1∶2). After thin layer chromatography, the contents of three polyamines, ie.putrescine(PTC), spermidine(SPD), and spermine(SPM) in normal and infected erythrocytes were determined with fluorescence spectrometer. The changes of polyamine level in PS and PRB infected erythrocytes of mice treated by a single oral dose of PND 5 and 10 mg/kg respectively were also observed.RESULTS: The contents of PTC, SPD and SPM in PS infected erythrocytes were 47 5±28 6, 97 7±34 0 and 81 7±23 8 nmol/10 9 RBC (n=9), respectively, being 1 5, 3 5, and 6 6 times of those appeared in the normal RBC (32 0±9 9, 28 2±12 3, and 12 4±15 0 nmol/10 9 RBC, n=9), respectively. The differences between two groups were significant.Interestingly, when mice infected with pyronaridine resistant line PRA and PRB, the contents of PTC, SPD and SPM in the infected erythrocytes increased to 187 7±139 9, 258 3±137 9 and 142 8±143 8 nmol/10 9 RBC (n=18), and 345 5±223 0, 435 8±265 4 and 189 4±171 7 noml/10 9 RBC, respectively. Except for SPM, PTC and SPD in the PRA and PRB infected erythrocytes were significantly higher than those in the PS and PRA infected erythrocytes, respectively, being 3 9, 2 6 and 1 8, 1 7 times of those appeared in PS and PRA infected erythrocytes. In PND treated group, SPD and SPM contents of PS infected erythrocytes were decreased by 31 6% and 47 3% compared with non treated group, but the polyamine level of PRB infected erythrocytes did not significantly change after PND administration. CONCLUSION∶ The resistance of P.berghei to PND is related to the alteration of polyamine metabolism in the malarial parasites.