大剂量维生素C对急性肺损伤的保护作用

目的观察大剂量维生素C(500mg/kg)对油酸诱导的家兔急性肺损伤的预防和治疗效果。方法30只家兔分为4组:对照组(CG),油酸组(OG),预防组(PG)及治疗组(TG)。于油酸注入前(0)及后30、90、150min采各组动物颈总动脉血测PaO2、超氧化物歧化酶(SOD)活力、血浆丙二醛(MDA)。实验末右肺测湿质量,取支气管肺泡灌洗液(BALF)后烤箱烘干得湿干质量比值,留少许左肺标本甲醛固定做切片。结果油酸注入30min后,PG组和TG组PaO2及SOD明显高于OG组(P<0.01);而MDA明显低于OG组(P<0.01)。实验末PG组和TG组BALF中总蛋白、肺湿干质量比较OG组低(P<0.05);肺组织病理切片显示损伤较轻。结论大剂量维生素C对油酸所致的家兔急性肺损伤,通过清除氧自由基而发挥保护作用。

Protective effect of large doses of vitamin C on acute lung injury

Objective To investigate the protective and therapeutic effect of large doses of vitamin C on the acute lung injury in the model of rabbits induced by oleic acid. Methods A total of 18 rabbits were divided into four group randomly: control group(CG); oleic acid group(OG); preventive group(PG) and treatment group(TG). Oxygen pressure in arterial blood (PaO_(2)), superoxide dismutase (SOD) and malondialdehyde(MDA) in blood were measured in 0, 30, 90 and 150min, respectively. All the animals were killed in 150min later. Total protein in broncho-alveolar lavage fluid (BALF) and wet dry weight ratio of the right lung were measured, and the left lung sample was treated by formaldehyde for pathological test. Results PaO_(2), SOD in PG group and TG group were significantly higher than that in OG group(P<0.01), and MDA significantly decreased (P<0.01) 30min after oleic acid injection; BALF and lung wet–dry weight ratio in PG group and TG group significantly decreased (P<0.05) compared with in OG group; HE staining showed that the lung injury in PG group and TG group was improved. Conclusion Large doses of vitamin C (500mg/kg) has preventive effect on acute lung injury.