阿片μ受体与SP、CGRP和SOM在大鼠三叉神经节和背根神经节内的共存研究

CO-LOCALIZATION OF μ-OPIOID RECEPTOR-AND SUBSTANCE P-,CALCITONIN GENE-RELATED PEPTIDE-, AND SOMATOSTATIN-IMMUNOREACTIVITY IN THE TRIGEMINAL AND DORSAL ROOT GANGLIA OF THE RAT

本研究应用免疫荧光及免疫荧光双重染色技术，观察了大鼠三叉神经节和背根神经节内阿片μ受体免疫反应阳性神经元的分布及其与SP、CGRP和SOM阳性神经元之间是否存在共存关系。结果显示：（1）三叉神经节和背根神经节内的阿片μ受体免疫反应阳性神经元多为中小到细胞，其免疫反应阳性产物不仅见于胞膜表面也出现于胞浆内。SP和SOM免疫反应阳性神经元亦为中小型细胞，但以小细胞为主，而CGRP免疫反应阳性神经元有一部分为大型神经元。（2）在三叉神经节内，有相当数量的阿片μ受体阳性神经元同时呈SP、CGRP或SOM免疫反应阳性。其中双重免疫反应神经元分别占阿片μ受体阳性细胞总数的34．6％、54．3％和23.9％，而在SP、CGRP和SOM各阳性细胞中分别有49．4％、50．9％和37.5％的神经元同时是阿片μ受体免疫反应阳性．（3）在背根神经节内，也有相当数量的神经元呈阿片μ受体与SP、CGRP和SOM双重免疫反应阳性，其中双标细胞数分别占阿片μ受体免疫反应阳性细胞总数的30．1％、48．4％和26.8％，各占SP、CGRP和SOM阳性细胞总数的51．5％、44．2％和35．9％。本文结果提示吗啡的镇痛作用中有部分可能是通过激活阿片μ受体来影响初级传入纤维中SP、CGRP和SOM的释放而实现的．

In the present study, the immunofluorescence and double- immunofluoresence histochemical techniques were usedto examine the distribution of μ-opioid receptor(MOR) and co-localization of MOR-like irnmunoreactivity (LI) with sub-stance P (SP)-, calcitonin gene-related peptide(CGRP)-, and somatostatin(SOM)- LI in the ganglion cells of the trigeminaland dorsal root ganglia in the rat. The results showed: (1) the majority of the ganglion cells with MOR-like immunoreac-tivity were small to medium-sized. The immunoreactive products were not only seen on plasmalemma, but also observedwithin the cytoplasm. The vast majority of the ganglion cells with SP- and SOM-LI were small, and of ganglion cell withCGRP-LI was small to medium-sized; (2) the double-immunofluoresence staining analysis revealed that a substantial num-ber uf MOR-LI ganglion cells co-existed with SP-, CGRP-, or SOM-immunoreactive cell in the trigerninal ganglion of therat. Cell counts showed that about 34. 6 %, 54. 3 % and 23. 9% of MOR-LI neurons were immunostained with SP-, CGRP-,and SOM-LI, respectively. On the other hand, among SP-, CGRP- and SOM-LI neurons - MOR-LI was exhibited in about49. 4%, 50. 9 % and 37. 5 % of the neurons; (3) In the dorsal root ganglia, a considerable number of the neurons were dou-bly labeled with MOR/SP, MOR/CGRP and MOR/SOM-LI. Of the total population of MOR-LI neurons, about 30. 1%,48. 4% and 26. 8 % neurons also showed SP-, CGRP- or SOM-LI. of the total population of SP-,CGRP- and SOM-LI neu-rons, about 51. 5 %, 44. 2 % and 35. 9 % neurons were immunbetained with MOR-LI, respectively. The present results sug-gested that analgesic effects of morphine, at least partially, might be carried out through modulating the release of SP,CGRP and SOM from the somatic primary afferent terminals via activation of MOR.