硫化氢对大鼠肠缺血再灌注后回肠收缩活性的保护作用

摘要

肠缺血再灌注(I/R)在临床中较为常见,并可引起严重的并发症,目前仍缺乏有效的治疗药物.目的:研究硫化氢(H2S)对大鼠肠I/R后离体回肠收缩活性的影响及其机制.方法:24只Sprague-Dawley大鼠随机分为正常组、假手术组、I/R组(I1h/R4h)、H2S组(再灌注前20 min腹腔内注射硫氢化钠10 μmol/kg).记录离体回肠自发收缩频率和曲线下面积(AUC),观察离体回肠对KCl(30 mmol/L)、乙酰胆碱(Ach)( 10-5 mol/L)、电场刺激(EFS)(30 V,10 Hz,1.00 ms,10 s)的反应.以免疫荧光染色检测肠肌间神经丛中Hu、胆碱乙酰转移酶(ChAT)阳性神经元表达.结果:与假手术组相比,I/R组和H2S组大鼠离体回肠自发收缩频率、对KCl和Ach的反应无明显改变.I/R组自发收缩AUC和对EFS的反应明显下降(P＜0.05),Hu、ChAT阳性神经元表达均明显降低(P＜0.05)；给予H2S干预后,上述指标均明显升高(P＜0.05).结论:H2S对大鼠肠I/R后回肠收缩活性可产生保护作用,其机制可能是减轻了肠神经元尤其是兴奋性神经元的损伤.%Ischemia-reperfusion (I/R) injury is common and can cause severe complications, but there are only a few drugs showing promising effects. Aims: To investigate the protective effect and mechanism of hydrogen sulfide (H2S) on the contractile activity of isolated ileum induced by I/R in rats. Methods: Twenty-four SpragueDawley rats were randomly divided into normal control group, sham-operated group, I/R (I1h/R4h) group, H2S group (NaHS 10 μmol/kg injected intraperitoneally 20 minutes before reperfusion). Functional studies were carried out by recording the frequency and area under curve (AUC) of spontaneous contraction of isolated ileum, and responses to KC1 (30 mmol/L), acetylcholine (Ach) (10-5 mol/L) and electrical field stimulation (EFS) (30 V, 10 Hz, 1.00 ms, 10 s). Immunofluorescenee staining was used to detect the expressions of Hu-positive and choline acetyl transferase (ChAT)-positive enteric neurons in myenteric plexus. Results: Compared with sham-operated group, no significant differences in frequency of spontaneous contraction, responses to KC1 and Ach were found in I/R group and H2S group. AUC of spontaneous contraction and the response to EFS, and expressions of Hu-positive and ChAT-positive enteric neurons were significantly decreased (P<0.05). After intervention with H2S, all the above-mentioned indices significantly increased (P<0.05). Conclusions: H2S shows protective effect on contractile activity of rat ileum induced by I/R. The mechanism is probably related to the alleviation of enteric neurons injury by H2S, especially the excitatory neurons.