口服硝酸盐对大鼠背部随意皮瓣的保护作用及机制探讨

The effect of dietary nitrate on rat dorsal random flap and its mechanism

目的 :探讨口服硝酸盐对大鼠背部随意皮瓣的影响,以硝酸盐-亚硝酸盐-NO通路为切入点,探讨其可能的机制。方法:将24只雄性Wistar大鼠随机分为硝酸盐组、氯化钠组和对照组,每组8只。采用改良大鼠背部随意皮瓣制作方法造模。硝酸盐干预组在术前7 d及术后每天口服0.5 mmol/L硝酸钠,氯化钠组每天口服等量氯化钠,对照组每天口服蒸馏水。术后第7天,检测各组皮瓣的存活情况,大鼠血清中硝酸盐、亚硝酸盐、肿瘤坏死因子(tumor necrosis factor alpha,TNF-a)和白介素6(interleukin-6,IL-6)水平,以及皮瓣组织中超氧化物歧化酶(superoxide dismutase,SOD)和丙二醛(malondialdehyde,MDA)水平。采用SPSS 20.0软件包对数据进行t检验。结果:硝酸盐组皮瓣的存活面积显著高于对照组(P<0.05)。H-E染色显示,硝酸盐明显减轻了皮瓣的组织学损伤。硝酸钠显著增加了血清中硝酸盐和亚硝酸盐水平(P<0.05),并显著下调血清中TNF-a和IL-6水平(P<0.05)。此外,硝酸盐组皮瓣组织内MDA表达显著减少(P<0.05),SOD表达显著增加(P<0.05)。结论:口服硝酸盐可通过调控皮瓣的氧化应激和炎症反应保护皮瓣。

PURPOSE: To investigate the effect of oral nitrate on the survival of rat dorsal random flap, and to explore its potential mechanism by taking nitrate-nitrite-NO pathway as the breakthrough point. METHODS: Twenty-four healthy adult male Wistar rats were randomly divided into 3 groups(n=8). Modified McFarlane rat dorsal random skin flap was used to make the model. The experimental group was given 0.5 mmol/L sodium nitrate 7 days before operation and daily after operation, while the control group was given the same amount of sodium chloride daily, and the blank group was giv-en distilled water daily. The survival area of the flap was observed on the 7 th postoperative day. On the 7 th day after oper-ation, the contents of serum nitrate and nitrite in rats were detected, and the levels of TNF-α and IL-6 in serum were further detected. Meanwhile, histological changes of skin flap were observed and the levels of malondialdehyde(MDA) and superoxide dismutase(SOD) were analyzed in flap tissue samples. The data were analyzed with SPSS software package.RESULTS: The survival area of the flap in the experimental group was significantly higher than that in the control group on the 7 th day after operation, and the serum nitrate and nitrite contents were significantly higher than those in the control group. At the same time, H-E staining found that nitrate reduced the histological damage of the flap. Through observation of the expression of serum TNF-α and IL-6, it was found that nitrate reduced inflammatory reaction. In addition, the oxidative stress marker MDA was reduced, while the activity of SOD was restored after nitrate treatment. CONCLUTIONS:Oral nitrate can improve the survival area of random flap in rats. The mechanism is associated by promoting angiogenesis and reducing circulating inflammatory factors through nitrate-nitrite-NO pathway.