膀胱伤害性刺激条件下大鼠腰骶髓后连合核及背根节内SP的动态变化

CHANGES OF SUBSTANCE P IN DORSAL COMMISSURAL NUCLEUS AND DORSAL ROOT GANGLIA OF THE RAT LUMBOSACRAL RESPONDING TO BLADDER NOCICEPTIVE STIMULUS

将１０％福尔马林１．０～１．５ｍｌ经尿道注入大鼠膀胱，于刺激后的０．５，１，２，８，２４，４８ｈ取材，进行兔疫组化（ＡＢＣ法）反应，观察脊髓腰骶段后连合核区的ＳＰ样纤维和终末的分布，并随机抽样进行图像分析、另设对照组，向膀胱内注入生理盐水，０．５，２．０ｈ后取材。结果显示：福尔马林刺激后，腰骶髓后连合核区ＳＰ样阳性纤维和终末与对照组相比，在ｌｈ内明显减少，而在２ｈ时则呈增加趋势，８ｈ又恢复正常。同时本文以同样动物模型，实验组分别于刺激后１，３，８，１２，２４，４８ｈ和５ｄ取材，对照组于刺激后２４ｈ取材，进行原位杂交组化反应，观察腰骶髓背根神经节内ＳＰｍＲＮＡ阳性神经元的数量。结果显示：福尔马林刺激后３ｈ即出现ＳＰｍＲＮＡ表达神经元数量的明显增加，２４ｈ达到高峰，并在４８ｈ以后开始下降，到５ｄ后回落到正常水平。

Changes of substance P-like immunoreactivity (SP-LI) in the lumbosacral dorsal commissural nucleus (DCN) were in-spected microscopically and semiquantified with a computer-assisted image processing system in rats with different times (0.5 h, 1 h, 2 h, 8 h, 24 h, 48h) after injection of 1. 0～1.5 ml 10% formalin into the bladder via the urethra. The resultsshowed that SP-LI in DCN significantly decreased from 0. 5 hour to 1 hour after injection, wereas SP-LI significantly in-creased at about 2 hours after the injection. After 8 hours, the levels of SP-LI was almost equal to that of the controlgroups. We also inspected the changes of SP-mRNA expression in the lumbosacral dorsal root ganglian(DRG) neurons andsemiquantified microscopically with different times (1 h, 3 h, 8 h , 24 h, 48 h, 5 d) after the same injection in situ. The re-sults showed that the numbers of SP mRNA-POsitive neurons in DRG significantly increased from 3 hours after injection.The SP mRNA-positive neurons increased to the peak at 24 hours (P<0.01). After 5 days of injection, the numbers of SPmRNA positive neurons decreased to the level of contral groups.