海带多糖对心理应激大鼠血管舒张功能的保护作用

目的 探讨海带多糖对心理应激大鼠血管舒张功能的保护作用及相关机制。方法 采用愤怒心理应激的方法制备血管内皮损伤大鼠模型，实验分为对照组、模型组、海带多糖低和高剂量组及低分子肝素组。造模后取血，采用ELISA法检测血浆肾上腺素（Adr）水平、血管性血友病因子（vWF）水平，采用放射免疫化学法检测血浆皮质醇、6-酮-前列腺素F_1α（6-keto-PGF_1α）的水平，采用化学法检测血浆NO水平。取血后，制备大鼠血管环，观察各组大鼠血管环对累计浓度乙酰胆碱（Ach）的内皮依赖性舒张反应。结果 与对照组比较，模型组、海带多糖组和低分子肝素组血浆皮质醇和Adr水平明显升高（P＜0.05）；海带多糖高剂量组血浆vWF水平与模型组比较明显降低（P＜0.05）；海带多糖高剂量组血浆NO水平与模型组比较显著升高（P＜0.05）；海带多糖组血浆6-keto-PGF_1α水平与模型组比较显著升高（P＜0.05）；与模型组比较，海带多糖高剂量组血管舒张反应明显增强（P＜0.05）。结论 海带多糖对心理应激大鼠血管舒张功能具有一定的保护作用。

Protection of laminaria polysaccharide on vasodilation function of rats induced by psychological stress

Objective To explore the protection of laminaria polysaccharide (LP) on vasodilation function of rats induced by psychological stress and its relative mechanism. Methods Normal adult rats were randomly divided into control, model, LP-L, LP-H, and low molecular heparin groups. The rat model with endothelial damage was built up by anger psychological stress method. After psychological stress, the levels of adrenaline (Adr) and von Willebrand factor (vWF) in plasma of rats were tested by ELISA, cortisol and 6-Keto-PGF_1a were tested by radioimmunoassay, and the level of nitric oxide (NO) in plasma of rats was tested by chemical colorimetry. After taking blood, the aortic rings were prepared and put into organ bath. The tension of endothelium-dependent relaxation induced by acetylcholine (Ach) was recorded. Results Compared with the control group, the level of cortisol and Adr in plasma increased significantly in the model, LP-H, LP-L, and low molecular heparin groups (P<0.05). Compared with the model group, the level of vWF in plasma decreased significantly in LP-H group (P<0.05), and the level of NO in plasma of rats in LP-H group was higher than that in the model group significantly (P<0.05). The level of 6-Keto-PGF_1a in plasma of rats increased significantly in LP-H and LP-L groups (P<0.05). Compared with the model group, endothelium dependent relaxation of isolated thoracic aorta in rats induced by Ach significantly increased in LP-H group (P<0.05). Conclusion LP could protect the vasodilation function of rats induced by psychological stress.