Abstract: Objective To study the lethal effect of exogenous nitric oxide donor sodium nitroprusside （SNP） on the muscle larvae of Trichinella spiralis in vitro cultivation. Methods T. spiralis muscle larvae isolated from the infected BALB/c mice were formulated into a 1 000 larva/ml suspension with RPMI 1640 medium， and 0.1 ml suspension per orifice was cultured with SNP at 37℃ in a humidified 5% CO2 atmosphere. The final concentrations of SNP were 0， 0.02， 0.05， 0.10， 0.20， 0.50 and 1.00 mmol/L， respectively， and then the experiments were divided into 5 groups： a control 1.00 mmol/L SNP group （Group A）， 0.15 mmol/L FeSO4+1.00 mmol/L SNP （Group B）， 1.00 mmol/L L?cysteine+1.00 mmol/L SNP （Group C） ， 0.15 mmol/L FeSO4+1.00 mmol/L L?cysteine+ 1.00 mmol/L SNP （Group D） and 0.15 mmol/L Hemoglobin+1.00 mmol/L SNP （Group E）. All the groups were incubated with T. spiralis muscle larvae in RPMI 1640 medium. The survivability of the muscle larvae was observed by steromicroscope and the differences of inhibition ratio among these groups were analyzed 4 days after the incubation. Results SNP 0.02 mmol/L was not cytotoxic to the muscle larvae with an inhibition of （5.50±1.80） %. The mortality rates of SNP 0.05， 0.10， 0.20， 0.50， 1.00 mmol/L groups were （20.19±2.71）%， （29.21±2.12）%， （41.81±2.03）%， （47.85±3.79）%， （60.98±5.19）%， respectively， significantly higher than that of the blank control group［（4.93±0.25）%， P < 0.05］. There was a positive liner correlation between the mortality of muscle larvae and SNP concentrations in the range of 0.02?1.00 mmol/L. Next， Group A， B， C，D and E led to the mortality from （60.98±5.19）% to （49.48±1.34）%， （47.29±2.79）%， （26.28±1.37）%， （17.93±3.49）%， respectively. Compared with the control Group A， the other four groups had all significant differences （P < 0.05）. Conclusion Exogenous nitric oxide released from SNP can kill the muscle larvae of T. spiralis. However， hemoglobin， L?cysteine， and FeSO4 can reverse the lethal effect on the parasites. The best inhibitor was hemoglobin.

Key words: Trichinella spiralis； Muscle larvae； Sodium nitroprusside； Nitric oxide； In vitro

摘要： 目的 探讨亚硝基铁氰化钠（SNP）来源的NO体外杀伤旋毛虫肌幼虫的作用及其相关机制。方法 制作浓度为1 000条/ml的旋毛虫肌幼虫悬液。培养板每孔加入0.1 ml肌幼虫悬液，再加入SNP，使其终浓度分别为0.02、0.05、0.10、0.20、0.50 mmol/L和1.00 mmol/L，并设空白对照组， 37 ℃ 5% CO2培养箱中孵育4 d后收集各孔肌幼虫，镜检计数，计算并比较各组肌幼虫死亡率。另于培养板中每孔加入0.1 ml肌幼虫悬液，分别设A组（对照组，1.00 mmol/L SNP）、B组（0.15 mmol/L FeSO4+ 1.00 mmol/L SNP）、C组（1.00 mmol/L L?半胱氨酸+ 1.00 mmol/L SNP）、D组（0.15 mmol/L FeSO4 + 1.00 mmol/L L?半胱氨酸+ 1.00 mmol/L SNP）、E组（0.15 mmol/L Hb+ 1.00 mmol/L SNP），培养、检测方法同前，计算并比较各组肌幼虫死亡率。结果 0.02 mmol/L SNP组与空白对照组的旋毛虫肌幼虫死亡率分别为（5.50 ± 1.80）%和（4.93 ± 0.25）%（P > 0.05）。SNP 0.05、0.10、0.20、0.50、1.00 mmol/L组虫体死亡率分别为（20.19 ± 2.71）%、（29.21 ± 2.12）%、（41.81 ± 2.03）%、（47.85 ± 3.79）%和（60.98 ± 5.19）%，与空白对照组比较均有统计学意义（P均< 0.05）。旋毛虫肌幼虫死亡率与SNP浓度呈正相关（rs = 0.875，P < 0.05）。B、C、D、E实验组肌幼虫死亡率分别为（49.48 ± 1.34）%、（47.29 ± 2.79）%、（26.28 ± 1.37）%和（17.93 ± 3.49）%，均较A组（60.98 ± 5.19）%有所下降（P均< 0.05）。结论 SNP来源NO对体外培养的旋毛虫肌幼虫具有杀伤作用，而血红蛋白、硫酸亚铁、L?半胱氨酸对该杀伤具有抑制作用，以血红蛋白抑制效果最显著。

关键词: 旋毛虫；肌幼虫；亚硝基铁氰化钠；一氧化氮；体外研究