大鼠背根切断后脊髓后角Ⅰ～Ⅲ层和外侧脊核区内鸟核苷酸调节蛋白的改变

背景:在国内本实验室曾首次报道脊髓胶状质及外侧脊核核区出现强的αo免疫反应性,与一些参与感觉调控的神经肽在该区的分布类似,提示鸟核苷酸调节蛋白可能与一级传入信息的传递有关。目的:采用切断大鼠单侧背根后观察胶状质内αo免疫反应性的改变。设计:随机对照动物实验。单位:华中科技大学同济医学院神经生物学教研室。材料:实验于1995-12/1996-12在华中科技大学同济医学院神经生物学教研室完成。选择SD健康成年大鼠15只,随机分为3组:①正常组5只(未经任何处理)。②切断背根组10只(右侧)。③对照组(未切断背根的左侧作为对照)。方法:大鼠在100g/L水合氯醛(300mg/kg)腹腔注射麻醉下,切断右侧腰1～3脊神经背根,术后存活48～60h。用兔抗鸟核苷酸调节蛋白αo亚单位多克隆抗血清,采用免疫组织化学方法来观察大鼠脊髓内αo免疫反应性,对鸟核苷酸调节蛋白进行定位,观察其在切断脊神经背根后的改变情况。主要观察指标:①正常鼠和对照组鼠脊髓后角Ⅰ～Ⅲ层及外侧脊核区的αo免疫反应性。②切断背根组鼠脊髓后角Ⅰ～Ⅲ层及外侧脊核区的αo免疫反应性。结果:15只大鼠均进入结果分析。①正常鼠和对照组鼠脊髓后角浅层(Ⅰ～Ⅲ)均出现强的αo免疫反应性,第二层(胶状质)最为密集,外侧脊核区也出现αo免疫反应性纤维网。切断背根后胶状质内αo免疫反应性明显降低。②αo免疫反应性吸光度定量分析,对照组内侧区0.847±0.081,切断背根组内侧区0.633±0.073(t=5.71,P<0.001);对照组中间区0.823±0.089,切断背根组中间区0.6604±0.074(t=6.90,P<0.001);对照组外侧区0.915±0.090,切断背根组外侧区0.656±0.077(t=10.31,P<0.001);对照组平均值0.852±0.084,切断背根组平均值0.639±0.078(t=10.23,P<0.001)。结论:胶状质内与一级伤害性刺激传入有关的神经元末梢内鸟核苷酸调节蛋白部分来源于一级感觉神经元,提示鸟核苷酸调节蛋白可能参与调控一级感觉的传递。

Change of the guanine nucleotide-binding protein in lamina Ⅰ-Ⅲ of spinal cord posterior horn and lateral spinal nucleus of rats after transection of dorsal roots

BACKGROUND: In China, this laboratory is the first one to report such researches, confirming that strong αo-immunoreactive (IR) appears in the substantia gelatinosa (SG) of spinal cord and lateral spinal nucleus which is similar to the distribution of certain neuropeptides that participate in sensory regulation, which suggests that guanine nucleotide binding protein (G protein) may be related to primary afferent informational transfer. OBJECTIVE: To observe the change of αo-IR in gelatinous substance by the method of transection of unilateral spinal dorsal roots.DESIGN: A randomized controlled experiment on animals.SETTING: Staff Room of Neurobiology, Tongji Medical College, Huazhong University of Science and Technology.MATERIALS: The experiment was conducted at the Staff Room of Neurobiology, Tongji Medical College, Huazhong University of Science and Technology from December 1995 to December 1996. Fifteen healthy adult SD rats were selected and divided into 3 groups: ①normal group with five rats (not dealt with any disposal), ②transected dorsal root group with 10 rats (right side) and ③control group (non-transected left sidedness as control).METHODS: Right lumbar 1-3 spinal neural dorsal roots were cut off under the anesthesia of 100 g/L chloral hydrate (300 mg/kg)through intraperitoneal injection in rats, living for 48-60 hours after operation. The subunit αo of guanine nucleotide-binding protein (rabbit polyclonal antiserum) was demonstrated in the αo-IR of rat spinal cord by immunohisto chemical methods. G protein was oriented, and its change was observed after transection ofneural dorsal roots MAIN OUTCOME MEASURES: ①The αo-IR of Ⅰ to Ⅲ of the dorsal horn and lateral spinal nucleus of the normal rats and control rats. ②The αo-IR of Ⅰ to Ⅲ of the dorsal horn and lateral spinal nucleus of rats in the transected dorsal root group. RESULTS: Data of a total of 15 rats were involved in the result analysis. ①In the normal group and control group, intense αo-IR was presented in rexed lamina ( Ⅰ to Ⅲ ) of the dorsal horn of rats, and the highest αo-IR in second lamina (SG). Lateral spinal nucleus of rat revealed higher density of αo-IR containing fiber networks. Following unilateral transection of dorsal roots in SG, αo-IR was markedly decreased. ②Quantitative analysis of absorbance (A) of αo-IR, it was (0.847±0.081) in the inside of the control group, (0.633±0.073)(t=5.71 ,P ＜ 0.001 ) in the inside of transected dorsal root group. It was (0.823±0.089) in the middle area of the control group,(0.660 4±0.074)(t=6.90,P ＜ 0.001 ) in the middle area of the transected dorsal root group. It was (0.915±0.090) in the lumbar region of the control group, and (0.656±0.077)(t=10.31 ,P ＜ 0.001 ) in the lumbar region of the transected dorsal root group. Average value of the control group was (0.852±0.084), and average value of the transected dorsal root group was (0.639±0.078)(t=10.23 ,P ＜ 0.001 ).CONCLUSION: Part of G protein of end-brush neurons related with the primary afferent noxious stimulation in SG derives from primary sensory neurons, which maybe join the adjustment of primary sensory transfer.