肾上腺素、瞬时受体电位香草酸1通道和P物质在急性脊髓损伤大鼠并发肺损伤中的变化及意义

目的 探讨肾上腺素、瞬时受体电位香草酸1（TRPV1）通道和P物质在大鼠急性脊髓损伤（ASCI）并发肺损伤中的变化及意义。方法 将228只雌性SD大鼠按随机数字表法分为假手术组（90只）、ASCI组（108只）、双侧肾上腺切除组（15只）、双侧肾上腺切除后ASCI组（15只）。采用改良Allen''s打击模型（打击锤质量为10 g，打击高度为25 mm）于T₁₀脊髓节段制备ASCI模型，假手术组仅暴露T₁₀节段脊髓，双侧肾上腺切除后ASCI组于肾上腺切除术5 d后制作ASCI模型。采用高效液相色谱法检查大鼠血清肾上腺素水平。取大鼠肺组织标本，计算肺湿干质量比以反映肺组织水肿变化，采用H-E染色检测肺组织病理学变化，采用免疫组织化学染色、蛋白质印迹法检测肺组织中TRPV1蛋白表达，采用酶联免疫吸附试验检测肺组织中P物质的含量。结果 脊髓损伤后2、6、12、24、48、72 h，ASCI组大鼠血清肾上腺素水平均高于假手术组，差异均有统计学意义（P均<0.01）。脊髓损伤后24、48、72 h，ASCI组大鼠肺水肿和肺损伤组织病理学变化逐渐加重，损伤1周时开始恢复。脊髓损伤后24、48、72 h，ASCI组大鼠肺组织TRPV1蛋白表达量和P物质含量均较假手术组升高，差异均有统计学意义（P均<0.05，P均<0.01）。脊髓损伤后72 h，双侧肾上腺切除后ASCI组肺组织水肿和组织病理学变化均较ASCI组减轻。结论 肾上腺素可能参与大鼠ASCI并发的肺水肿和肺损伤进程，这种效应可能与肺组织中TRPV1、P物质的表达上调有关；双侧肾上腺切除预处理可减轻ASCI并发的肺水肿和肺损伤程度。

Adrenaline, transient receptor potential vanilloid 1 channel and substance P in rats with acute spinal cord injury complicated with lung injury

Objective To study the changes and significance of adrenaline, transient receptor potential vanilloid 1 (TRPV1) channel and substance P in rats with acute spinal cord injury (ASCI) complicated with lung injury. Methods Two hundred and twenty eight female Sprague-Dawley rats were randomly divided into sham operation group (sham group, n=90), ASCI group (n=108), bilateral adrenalectomy group (n=15), and ASCI after bilateral adrenalectomy group (n=15). The ASCI model was established on the T₁₀ spinal cord segment using a modified Allen''s strike model (10 g, 25 mm). The sham group only exposed the T₁₀ spinal cord, and the ASCI after bilateral adrenalectomy group was established 5 days after bilateral adrenalectomy. High-performance liquid chromatography was used to detect the changes of serum adrenaline. The pulmonary tissue specimens were collected from rats. Wet-to-dry lung weight ratio was used to detect the changes of pulmonary edema, and H-E staining was used to detect the pathological changes of lung tissue. The expression of TRPV1 protein in lung tissue was detected by immunohistochemistry and Western blotting. The contents of substance P in the lung tissue were detected by enzyme-linked immunosorbent assay. Results Serum adrenaline levels in the ASCI group were significantly higher than those in the sham group at 2, 6, 12, 24, 48, and 72 h after spinal injury (all P<0.01). The pulmonary edema and lung injury gradually aggravated in the ASCI group at 24, 48 and 72 h after spinal injury, and began to recover at 1 week. The expression levels of TRPV1 protein and substance P contents in ASCI group were significantly upregulated compared with the sham group at 24, 48, and 72 h after spinal injury (all P<0.05, P<0.01). The edema of lung tissue and pathological injury in the ASCI after bilateral adrenalectomy group were alleviated compared with the ASCI group 72 h after spinal injury. Conclusion Adrenaline may involve in the pathogenesis of pulmonary edema and lung injury in rats with ASCI, which may be related to the upregulation of TRPV1 and P substance expression. The pulmonary edema and lung injury after ASCI can be alleviated by adrenalectomy.