预混水杨酸钠对大鼠急性百草枯中毒生存率的影响

目的探讨预混水杨酸钠（NASAL）对急性百草枯（PQ）中毒大鼠生存率及肺损伤的影响。方法Wistar大鼠59只随机分为正常对照组、NASAL对照组、2组PQ组和2组PQ＋NaSAL预混组。正常对照组（n=6）采用生理盐水（NS）腹腔注射；NASAL对照组（n=6）予腹腔NASAL（300mg／kg）；2组PQ组用PQE25mg／kg（n=11）或35mg／kg（n=12）]腹腔注射一次性染毒；2组预混组（n=12）：分别一次性给予PQ（25mg／kg）和NASAL（200mg／kg）预混溶液，以及PQ（35mg／kg）和NASAL（300mg／kg）预混溶液。观察各组28d生存率及肺病理学改变。结果PQ25mg／kg组与PQ35mg／kg组生存率分别为36％和50％，2组预混组的生存率分别为33％和50％，PQ组与预混组各组问28d生存率差异无统计学意义（P〉0．05）。病理学研究显示PO组急性期肺病变主要为弥漫性肺泡炎性损伤，表现为肺泡及肺泡间隔炎性细胞浸润，肺泡腔内出血、渗出，后期主要表现为纤维组织增生沉积。预混组的病理学改变与PQ组相比无明显改善。结论从28d生存率和病理学角度观察，预混NASAL对急性PQ中毒大鼠的肺损伤无保护作用。PQ和NASAL混合后对PQ的毒性无明显影响。

Effect of premixed sodium salicylate on survival of rats after acute paraquat intoxication

Objective To investigate the effect ofpremixed sodium salicylate（NaSAL） solution on the survival and lung injury in rats after acute paraquat（PQ） intoxication. Methods A total of 59 Wistar rats were randomly divided into 6 groups as follows： normal control group（normal saline, n = 6）, NASAL control group（n = 6）, 2 PQ groups and 2 pre-mixed PQ ＋ NASAL groups. In PQ groups, rats were injected intraperitoneally with PQ of 25mg/kg （n = 11） or 35mg/kg（n = 12）, and then, with 0.9% NaC1 at 2h later. Pre-mixed PQ ＋ NASAL groups were divided into pre-mixed 25mg/kg PQ and 200mg/kg NASAL, （n = 12）, and pre-mixed 35mg/kg PQ and 300mg/kg NaSAL（n = 12）. In NASAL control group, rats were administered with 0.9% NaC1 solution, and then dosed with 300mg/kg NASAL at 2h later. All groups were observed daily for survival rate and poisoning symptoms over a period of at least 28d. Lung tissues were collected from rats died in the acute stage and those survived over 28d, and then observed with HE and Masson staining for pathological changes. Results The survival rates were 36% and 50% respectively in the 25mg/kg PQ group and 35mg/kg PQ group, and 33% and 50% respectively in the two premixed groups respectively. No significant difference was observed in the 28-day survival rates between PQ groups and pre-mixed PQ ＋ NASAL groups（P 〉 0.05）. Pathological observation showed that the rats exposed to PQ showed apparent lung changes at day 4 （acute stage）, including inflammatory cells infiltration into alveoli and alveolar septum, alveolar hemorrhage and effusion at the acute stage, and proliferation and accumulation of fibrotic tissues at the late stage. There was no significant difference in pathological changes between the PQ groups and pre-mixed PQ ＋ NASAL groups. Conclusions Pre-mixed PQ with NASAL shows no significant protective effect on rat lung injury induced by PQ intoxication. A pre-mixed PQ and NASAL solution doesn＇t counteract the toxic effect of PQ.