摘要
已有报道提出老龄化进程可能对伤害性行为表现有一定的影响 ,但是相关的机制仍不很明确。辣椒素受体 VR1(现命名为 TRPV1)已被证实为热伤害性感受器 ,老龄化进程中 TRPV1在痛传导路中的表达水平是否随年龄改变尚不清楚。本研究中应用免疫组织化学方法对三个年龄段 (青龄 :2～ 3月 ;中龄 :17～ 19月 ;老龄 2 4～ 2 6月 )大鼠脊髓背角的 TRPV1的表达进行了观察 ,结果显示 :(1) TRPV1在正常大鼠脊髓背角浅层的分布密度及其分布面积随年龄增长而逐渐减小 ;(2 )在外周致炎状态下 ,脊髓背角 TRPV1免疫反应产物密度在同年龄组内比较 ,青龄组减少 ,中龄和老龄组增加 ,而三年龄组内比较其分布面积时都明显增大 ,并且在非致炎组存在的组间差异消失。在青龄组大鼠 ,TRPV1免疫反应产物密度结果和分布面积结果并不一致 ,其原因未知。综上所述 ,本结果提示正常大鼠脊髓含 TRPV1的纤维终末随年龄增长而减少 ,但是在致炎情况下 ,TRPV1支配面积减少的现象消失。这可能是由于外周炎症刺激重新募集了背根节神经元 ,而老龄大鼠这种能力更强。本实验还提示 ,用免疫组织化学技术检测脊髓化学物质有无变化 。
It has been implied that aging process could have an effect on pain behaviors in response to nociceptive stimuli. However, the mechanisms underlying the age related change in pain perception are unclear. Vanilloid receptor 1 (VR1, now termed as transient receptor potential vanilloid 1, TRPV1) has been identified as a thermal nociceptor. It is in the darkness whether TRPV1 would change in the process of aging. Thus the present study was aimed to investigate the effect of age on the expression of TRPV1 in the spinal cord of normal rats and rats with peripheral inflammation induced by bee venom (BV). In this study, three time points of age were used: 2-3 months (young), 17-19 months (mid aged) and 24-26 months (aged). Our results showed an age related change in TRPV1 like immunoreactivity (TRPV1 LI) in the spinal cord of rats. The area occupied by TRPV1 LI in the spinal dorsal horn was expanded significantly under inflammatory pain state compared to normal state. Under normal state, the area of spinal TRPV1 LI distribution was decreased significantly with advancing age, while the trend to decrease under inflammatory pain state was not significant. Based upon our results, it is suggested that the level of spinal TRPV1 decreases with the process of advancing age in non inflamed rats and spinal TRPV1 area is increased by peripheral inflammation. And the increase of TRPV1 LI might attribute to peripheral inflammation induced increase in the amount of TRPV1 LI terminals in spinal dorsal horn. It is also suggested that maybe not only the density but occupied area of immunoreactivity should be considered to evaluate the change in the express of chemicals in spinal cord.
出处
《神经解剖学杂志》
CAS
CSCD
北大核心
2004年第2期137-142,共6页
Chinese Journal of Neuroanatomy
基金
The work was financially supported by grants of Chinese National Brain Science Basic Research Pro gram sponsored by the MOST(G1999054004)
of NSFC(30000051,30100052 and 30200077).
