McLain R F, Weinstein J N
Department of Orthopaedic Surgery, University of California, Davis, Sacramento 95817.
J Comp Neurol. 1992 Aug 22;322(4):538-47. doi: 10.1002/cne.903220408.
Normal adult rabbits were studied in a whole body vibration model which simulates the type of environmental exposure associated with vibration-induced low back pain. This model has previously been shown to induce changes in pain-related neuropeptides in the dorsal root ganglion. Following two weeks of daily exposure to whole body vibration, dorsal root ganglia were excised from control and vibrated rabbits and prepared for ultrastructural evaluation. Of over 1,200 cells sampled, 190 appropriately sectioned cells were analyzed: 32 from immobilized controls, 44 from normal controls, and 114 from vibrated animals. Analysis of nuclear contours revealed more prevalent and more extensive clefting of the nuclear membrane in vibrated cells. The membrane lining these clefts was traversed by numerous pores; density of these pores was 46% greater than in adjacent nonclefted segments (p less than .001). Number of clefts per nucleus was increased by 39% in vibrated animals. Cleft area represented 1.19% of nuclear area in vibrated cells compared to 0.74% in controls (p less than .001). Numerous mitochondria and free ribosomes and abundant rough endoplasmic reticulum were located within the cleft spaces of vibrated cells. Pores in the cleft membrane appeared normal, supporting the conclusion that the clefts are structural alterations rather than fixation or sectioning artifacts. Changes in dorsal root ganglion neuropeptides seen in previous studies of vibrated animals may result from increased or redirected cellular synthesis. Ultrastructural changes seen in these vibrated dorsal root ganglion neurons are consistent with such an alteration in metabolism and could reflect increased synthesis of pain-related neuropeptides.
在一个模拟与振动诱发的下背痛相关的环境暴露类型的全身振动模型中，对正常成年兔子进行了研究。此前已证明该模型可诱导背根神经节中与疼痛相关的神经肽发生变化。在每天暴露于全身振动两周后，从对照兔子和振动兔子身上切除背根神经节，并准备进行超微结构评估。在超过1200个采样细胞中，分析了190个切片合适的细胞：32个来自固定对照，44个来自正常对照，114个来自振动动物。对核轮廓的分析显示，振动细胞的核膜出现更普遍、更广泛的裂开。这些裂隙内衬的膜上有许多小孔穿过；这些小孔的密度比相邻的非裂开部分高46%（p小于0.001）。振动动物每个细胞核的裂隙数量增加了39%。振动细胞中裂隙面积占核面积的1.19%，而对照细胞中为0.74%（p小于0.001）。在振动细胞的裂隙空间内有许多线粒体、游离核糖体和丰富的粗面内质网。裂隙膜上的小孔看起来正常，支持了裂隙是结构改变而非固定或切片假象的结论。在先前对振动动物的研究中观察到的背根神经节神经肽变化可能是细胞合成增加或重新定向的结果。在这些振动的背根神经节神经元中观察到的超微结构变化与这种代谢改变一致，可能反映了与疼痛相关的神经肽合成增加。
