目的 探讨外源性一氧化氮(NO)对旋毛虫成虫的杀伤作用。 方法 取感染旋毛虫的BALB/c小鼠小肠组织,分离成虫,配制成虫悬液(1 000条/ml)。48孔板中每孔加入100 μl成虫悬液,再加入各组试剂,终浓度分别为:亚硝基铁氰化钠(SNP)0.02、0.05、0.10、0.20、0.50和1.00 mmol/L,1.00 mmol/L SNP+0.15 mmol/L血红蛋白(Hb)、1.00 mmol/L SNP+0.15 mmol/L 硫酸亚铁(FeSO4)、1.00 mmol/L SNP+1.00 mmol/L L-半胱氨酸(L-cyst)、1.00 mmol/L SNP+0.15 mmol/L FeSO4+1.00 mmol/L L-cyst,设空白对照组和阳性对照组(1.00 mmol/L SNP+100 μl肌幼虫悬液),每组设3个复孔。置37℃ 5% CO2培养箱中孵育,第4天收集各孔成虫,镜检并作番红染色,计算各组虫体死亡率。 结果 SNP 0.02 mmol/L和0.05 mmol/L组旋毛虫死亡率分别为(1.4±1.2)%和(3.2±1.0)%,这两组与空白对照组的死亡率[(1.9±0.2)%]之间的差异无统计学意义(P〉0.05)。SNP 0.10、0.20、0.50和1.00 mmol/L组虫体死亡率分别为(9.9±1.8)%、(37.7±2.5)%、(50.1±3.5)%和(80.8±1.1)%,与空白对照组之间的差异有统计学意义(P〈0.05)。SNP浓度在0.02~1.00 mmol/L范围内与旋毛虫成虫死亡率呈线性正相关(P〈0.05)。在1.00 mmol/L SNP的孔中分别加入Hb、L-cyst、FeSO4和FeSO4+L-cyst与仅SNP 1.00 mmol/L实验组比较,成虫死亡率均有所下降,分别为(56.5±3.7)%、(72.7±5.6)%、(74.8±2.4)%和(69.8±2.3)%。SNP 1.00 mmol/L组与SNP+Hb、SNP+FeSO4+L-cyst组旋毛虫成虫死亡率间的差异有统计学意义(P〈0.05)。 结论 外源性NO对体外培养的旋毛虫成虫有杀伤作用,而Hb、L-cyst+FeSO4可抑制该杀伤作用。
Objective To investigate the lethal effect of exogenous nitric oxide on adult worms of Trichinella spiralis in vitro. Methods Adult worms of T. spiralis isolated from the small intestine of Trichinella-infected BALB/c mice were cultured in RPMI 1640 medium with sodium nitroprusside(SNP) in different final concentration of 0, 0.02, 0.05, 0.10, 0.20, 0.50, and 1.00 mmol/L, 1.00 mmol/L SNP+0.15 mmol/L hemoglobin (Hb), 1.00 mmol/L SNP+0.15 mmol/L FeSO4, 1.00 mmol/L SNP+1.00 mmol/L L-cysteine (L-cyst), 1.00 mmol/L SNP+0.15 mmol/L FeSO4 +1.00 mmol/L L-cyst, respectively, and incubated at 37 ℃ in a humidified 5% CO2 atmosphere. On the 4th day after incubation, the adult worms were stained with safranin, and observed under light microscope. The worm mortality in the groups was analyzed. Results Under concentration of 0.02 and 0.05 mmol/L, SNP was not cytotoxic to adult T. spiralis with an inhibition of (1.4±1.2)% and (3.2±1.0)%, respectively. The worm mortality in the groups of SNP 0.10, 0.20, 0.50, and 1.00 mmol/L was (9.9±1.8)%, (37.7±2.5)%, (50.1±3.5)%, and (80.8±1.1)%, respectively, significantly higher than that of negative control group [(1.9±0.2)%, P〈0.05]. There was a positive linear correlation between the worm mortality and SNP concentration in the range of 0.02-1.00 mmol/L. Combination of hemoglobin, L-cyst, FeSO4 and FeSO4+L-cyst with 1.00 mmol/L SNP led to a decrease of the mortality from (80.8±1.1)% to (56.5±3.7)%, (69.8±2.3)%, (74.8±2.4)%, (72.7±5.6)%, respectively. Conclusion Exogenous nitric oxide released from SNP can kill adult worms of Trichinella spiralis. However, hemoglobin and L-cysteine+FeSO4 can reverse its lethal effect on the parasites.