皮下注射尼古丁对大鼠椎间盘退变的影响及其机制

Effects and mechanism of subcutaneous injection of nicotine on intervertebral disc degeneration in rats

目的观察皮下注射尼古丁对大鼠椎间盘退变程度的影响,分析椎间盘组织中水通道蛋白1(AQP1)和水通道蛋白3(AQP3)的表达变化,以探讨其影响的机制。方法取健康雄性Wistar大鼠30只,随机分为实验1组、实验2组及对照组各10只。实验1组和实验2组皮下注射尼古丁稀释液1.5 mL/(kg·d),对照组皮下注射等量生理盐水,连续5周。实验1组和对照组于实验5周后、实验2组于实验10周后处死,取L4/L5椎间盘组织,采用HE染色法观察椎间盘退变程度,免疫组化染色法检测椎间盘组织AQP1、AQP3表达。结果与对照组比较,实验1组和实验2组椎间盘组织结构模糊紊乱,严重炎性水肿、黏液样变性、层次不清,退变严重;与实验1组比较,实验2组的椎间盘各组织结构同样模糊紊乱,层次不清,但椎间盘纤维环有不同程度的基质填充。实验1组、实验2组AQP1、AQP3表达水平均较对照组降低(P均<0.05),实验2组AQP1、AQP3表达水平较实验1组升高(P均<0.05)。结论尼古丁可加速椎间盘退变,其机制可能与抑制AQP1、AQP3表达有关。

Objective To observe the effect of subcutaneous injection of nicotine on intervertebral disc degeneration in Wistar rats and to analyze the expression changes of aquaporin 1(AQP1)and aquaporin 3(AQP3).Methods Thirty healthy male Wistar rats were randomly divided into the experimental group 1,experimental group 2,and control group.Rats in the experimental group 1 and experimental group 2 were subcutaneously injected with nicotine diluent 1.5 mL/(kg·d),while the control group with normal saline for 5 weeks.Rats in the experimental group 1 and control group were killed at 5 weeks after experiment,and rats in the experimental group 2 were killed at 10 weeks after the experiment.The L4/L5 intervertebral disc tissues were stripped.HE staining was used to observe the degree of intervertebral disc degeneration,and immunohistochemical staining was used to detect the expression levels of AQP1 and AQP3 in intervertebral disc tissues.Results Compared with the control group,the intervertebral disc tissue structure of the experimental group 1 and experimental group 2 was fuzzy and disordered,with severe inflammatory edema,myxoid degeneration,unclear hierarchy and serious degeneration.Compared with the experimental group 1,the intervertebral disc structure in the experimental group 2 was also fuzzy and disordered with unclear layers,but the the intervertebral disc annulus fibrosus had different degree of matrix filling.The expression levels of AQP1 and AQP3 in the experimental 1 and experimental 2 were all lower than those in the control group(both P<0.05),while the expression levels of AQP1 and AQP3 in the experimental 2 were higher than those in the experimental 1 group(both P<0.05).Conclusion Nicotine can accelerate disc degeneration,and the mechanism may be related to the inhibition of the expression of AQP1 and AQP3.