Ciftci A O, Sara Y, Tanyel F C, Bozdag O, Orer H S, Onur R
Department of Pediatric Surgery, Faculty of Medicine, Hacettepe University, Ankara, Turkey.
J Pediatr Surg. 1999 Oct;34(10):1477-81. doi: 10.1016/s0022-3468(99)90107-0.
The contribution of nitrergic tone on the contractility of colonic smooth muscle in Hirschsprung's disease (HD) was investigated.
Ganglionic and aganglionic bowel specimens were taken from 8 patients with HD during pull-through operations and electrical field stimulation (EFS)-induced isometric contractions of the circular smooth muscle were recorded in vitro. Isolated circular muscle strips prepared from colonic segments of sex- and age-matched patients (n = 3) who underwent surgery for nonmotility-related colonic diseases formed the control group. Statistical analysis was performed by two way analysis of variance and unpaired Student's ttest.
The amplitude of spontaneous rhythmic activity was lower in aganglionic segments than in ganglionic ones. The amplitudes of contractile responses were significantly greater in aganglionic segments. In ganglionic preparations, N(omega)-nitro-L-arginine (L-NNA) addition into the medium increased the contractile responses to the level of aganglionic preparations. This increase was completely blocked by L-arginine application. Neither L-NNA nor L-arginine produced any change in aganglionic segments. A relaxation phase was detected in both ganglionic and aganglionic segments. In ganglionic preparations, this relaxation phase was completely inhibited by L-NNA and restored by L-arginine, whereas no effect was detected in aganglionic ones. Responses obtained from the control group were similar to the ganglionic segments of HD patients.
In normal colon and as well as in ganglionic segments of HD, the evoked contractile activity and relaxations are under the tonic influence of the nitrergic system. Aganglionic segments totally lack the nitrergic activity in both evoked contraction and relaxation responses, while still maintaining an inefficient relaxation capacity under unknown mechanisms.
研究了一氧化氮能张力对先天性巨结肠（HD）患者结肠平滑肌收缩性的影响。
在拖出式手术中从8例HD患者获取有神经节和无神经节的肠标本，并在体外记录电场刺激（EFS）诱导的环形平滑肌等长收缩。从因非动力相关结肠疾病接受手术的性别和年龄匹配患者（n = 3）的结肠段制备的分离环形肌条组成对照组。采用双向方差分析和非配对学生t检验进行统计分析。
无神经节段的自发节律活动幅度低于有神经节段。无神经节段的收缩反应幅度明显更大。在有神经节的标本中，向培养基中添加N（ω）-硝基-L-精氨酸（L-NNA）可使收缩反应增加到无神经节标本的水平。L-精氨酸的应用完全阻断了这种增加。L-NNA和L-精氨酸在无神经节段均未产生任何变化。在有神经节和无神经节段均检测到一个舒张期。在有神经节的标本中，该舒张期被L-NNA完全抑制，并被L-精氨酸恢复，而在无神经节的标本中未检测到影响。对照组获得的数据与HD患者的有神经节段相似。
在正常结肠以及HD的有神经节段中，诱发的收缩活动和舒张受一氧化氮能系统的紧张性影响。无神经节段在诱发的收缩和舒张反应中完全缺乏一氧化氮能活性，同时在未知机制下仍保持低效的舒张能力。
