大鼠脊髓损伤后P物质与神经源性肠道功能障碍的关系

Substance P in Neurogenic Bowel Dysfunction after Spinal Cord Injury in Rats

目的探讨脊髓损伤后结肠中P物质与神经源性肠道功能障碍的关系。方法 60只体质量(220±40)g的雄性SpragueDawley大鼠随机分为假手术组(n=20)、正常对照组(n=20)和模型组(n=20)。氯胺酮60 mg/kg腹腔注射麻醉大鼠,利用NYU脊髓打击器,以75 g·cm致伤力制作T10脊髓损伤模型,分别于造模后24 h、1周、3周和5周时切除大鼠结肠组织制作标本,检测肠道传输功能,采用ELISA方法测定血清中和组织中的P物质含量,实时荧光定量PCR和Western blotting法检测P物质mRNA和蛋白表达。结果模型组大鼠脊髓损伤后出现肠道传输功能下降,且于造模后3周时肠道传输达到最低值;造模后3周时模型组血清和组织中P物质含量与假手术组相比均降低,结肠组织中P物质的mRNA及蛋白表达水平也下调,与假手术组、正常对照组相比具有显著性差异,假手术组P物质的表达是模型组的(3.12±0.51)倍(P<0.05)。结论大鼠脊髓损伤后神经源性肠道功能障碍与结肠中P物质的表达降低有关。

Objective To investigate the relationship between neurogenic bowel dysfunction （NBD） and substance P in rats suffering from spinal cord injury （SCI）. Methods 60 male Sprague-Dawley rats, weighted （220±40） g, were randomly divided into three groups：sham group （n=20）, normal group （n=20） and model group （n=20） and then were subdivided into subgroups of 24 h, 1 week, 3 weeks, and 5 weeks respectively after SCI. SCI model was established at thoracic 10 segment of rat with NYU impactor device. The colon tissue of the rats was resected and stored. Substance P in serum and tissue was measured by ELISA. The tissue was examined by real-time RT-PCR and Western blotting to analyze the expression of substance P. Results The colon intestinal transmission function decreased and delineated at minimum value at 3 weeks in the model group. There was statistical significance with respect to the content of substance P in serum and tis-sue between the sham group and model group at 3 weeks. The expression of substance P in the sham group was （3.12± 0.51） times of the model group （P〈0.05）. Conclusion Substance P may take part in NBD after SCI in rats.