Terenghi G, Chen S, Carrington A L, Polak J M, Tomlinson D R
Department of Histochemistry, RPMS, Hammersmith Hospital, London, UK.
Acta Diabetol. 1994 Dec;31(4):198-204. doi: 10.1007/BF00571951.
This study examined the expression of the sensory neuropeptides, calcitonin gene-related peptide (CGRP) and substance P (SP), in the lumbar 4 and 5 dorsal root ganglion (DRG) and spinal cord of spontaneously diabetic BB rats and non-diabetic controls using quantitative immunohistochemical analysis. In both animal groups immunoreactivities for CGRP and SP were widely distributed within the neurons of DRG and in nerve fibres of the dorsal spinal cord. Image analysis of each neuropeptide subpopulation in the DRG showed that in diabetic rats the cell diameter of immunostained CGRP neurons was significantly decreased compared with controls, while no difference could be found for SP-immunoreactive (IR) neurons. The decrease in the CGRP-IR cell diameter appeared to occur mainly in medium to large neurons (30-50 microns diameter; 2.2% controls, < 1% diabetes), this change being parallel to an increased frequency of small-size neurons (< 20 microns diameter) in diabetic rats (62% controls, 69% diabetes; P < 0.05). However, there was no statistical difference in the total number of cells immunostained for either CGRP or SP between control and diabetic rats. The ratio of CGRP or SP neurons compared to total cells in the ganglion was similar in control and diabetic groups. No difference could be observed for peptide immunoreactivity in the dorsal and ventral horns of either control or diabetic animals. The observed changes of perikaryal size in diabetic rats might relate to the reduced axonal calibre and conduction velocity observed in these animals, and indicate that subpopulations of sensory neurons are affected differently by diabetes.
本研究采用定量免疫组织化学分析方法，检测了自发性糖尿病BB大鼠和非糖尿病对照大鼠的腰4和腰5背根神经节（DRG）及脊髓中感觉神经肽降钙素基因相关肽（CGRP）和P物质（SP）的表达。在两个动物组中，CGRP和SP的免疫反应性广泛分布于DRG的神经元和脊髓背侧的神经纤维中。对DRG中每个神经肽亚群的图像分析显示，与对照组相比，糖尿病大鼠中免疫染色的CGRP神经元的细胞直径显著减小，而SP免疫反应性（IR）神经元则未发现差异。CGRP-IR细胞直径的减小似乎主要发生在中大型神经元（直径30-50微米；对照组为2.2%，糖尿病组<1%）中，这种变化与糖尿病大鼠中小尺寸神经元（直径<20微米）频率的增加平行（对照组为62%，糖尿病组为69%；P<0.05）。然而，对照组和糖尿病大鼠中CGRP或SP免疫染色的细胞总数没有统计学差异。对照组和糖尿病组中，神经节中CGRP或SP神经元与总细胞的比例相似。在对照组或糖尿病动物的背角和腹角中，未观察到肽免疫反应性的差异。糖尿病大鼠中观察到的胞体大小变化可能与这些动物中观察到的轴突直径和传导速度降低有关，表明感觉神经元亚群受糖尿病的影响不同。
