硫化氢提高肠道微循环灌注保护新生儿坏死性小肠结肠炎

Exogenous H_2S up-regulates intestinal microcirculation to protect rats from neonatal necrotizing enterocolitis

目的探讨硫化氢(H_2S)对新生SD大鼠坏死性小肠结肠炎(NEC)的肠道微循环作用。方法出生12 h内的新生SD大鼠10只仅用于检测H_2S合成酶表达,另80只随机分为4组:正常对照组、NEC模型组、NEC+GYY4137组、NEC+AOAA组。各组分别予以腹腔注射生理盐水、LPS+生理盐水、LPS+GYY4137、LPS+AOAA。通过人工喂养-缺氧-冷刺激-脂多糖(LPS)方法复制新生鼠NEC模型。HE染色、病理评分以及动物显微镜拍实体照片显示肠组织损伤程度,并统计分析各组新生鼠生存时间,采用FLPI2激光散斑血流实时成像系统检测各组血流量变化,探讨H_2S对新生鼠NEC的肠道微循环保护作用。结果与模型组比较,当给与NEC处理鼠GYY4137时其肠组织血流量升高(P<0.05),病理评分降低(P<0.05);而给予AOAA时其病理评分较NEC组增加(P<0.05),但肠组织血流量差异并无统计学意义;NEC组较正常组病理评分增高,血流量降低。末端回肠与全肠组织血流量均值差异无统计学意义。结论 H_2S(7.5 mg/kg·d)可通过提高肠道微循环血流量保护NEC,提高NEC新生鼠生存率。

Objective To research the effect of H2S on intestinal microcirculation of newborn SD rats with neonatal neerotizing enteroeolitis （NEC）. Methods Ten newborn Sprague-Dewley （SD） rats were used to detect the expression of H2S synthase. Eighty SD rats were randomly divided into 4 groups： control group in which the rats were treated with 0.9% NaCl, NEC group in which the rats were treated with LPS＋0.9% NaCl, NEC＋GYY4137 group in which the rats were treated with LPS＋ GYY4137 and NEC＋AOAA group in which the rats were treated with LPS＋ AOAA. GYY4137 is the donor of H2S and AOAA is the inhibitor of cystathionine β-synthase （CBS）. The NEC model of SD rats was induced by bottle-feeding, hypoxia treatment, cold stimulation, and lipopolysaccharide （LPS） peritoneal injection for 3 days. Then HE stain, the Histologic Injury Score and photos taken under animal microscope were used to show the injury of intestinal tissues, What＇s more, the intestinal microvascular blood flow was detected by real-time imaging system of FLPI2 laser speckle blood flow and the survival time of the newborn rats was surveyed. The protective effect of H2S on intestinal microeirculation of newborn NEC rats was explored. Results Compared with the NEC group, the intestinal microvascular blood flow was significantly increased and the Histologic Injury Score was significantly decreased in the NEC ＋GYY4137 group （P 〈 0.05）. Importantly, administration of AOAA to the NEC rats significantly increased the Histologic Injury Score （P 〈 0.05）, but there was no significant difference in the intestinal microvascular blood flow between the NEC group and the NEC＋ AOAA group. When compared to the control group, the intestinal microvascular blood flow was significantly decreased and the Histologic Injury Score was significantly increased in the NEC group. Conclusions H2S [7.5 mg/（kg·d）] could protect newborn NEC rats and increase the survival rate by increasing blood flow of intestinal microcirculation.