胶原酶对大鼠脊神经背根神经节损伤的病理学研究

Pathologic Studies of Collagenase Damage on Dorsal Root Ganglion in Rats

【目的】通过病理学方法研究胶原酶对大鼠脊神经背根神经节的损伤情况。【方法】57只健康的Sprague-Dawley雄性大鼠分为正常对照组;急性胶原酶手术组、亚急性胶原酶手术组和慢性胶原酶手术组;急性生理盐水手术组、亚急性生理盐水手术组和慢性生理盐水手术组。暴露大鼠左侧腰5背根神经节,并在各胶原酶手术组局部滴注胶原酶1mL(300U),各生理盐水手术组局部滴注生理盐水1mL。分别于注药后1h、1周、30d处死动物并取包含背根神经节的一段神经做病理学检测。【结果】光镜下各组背根神经节的细胞数、胞膜、胞浆、胞核形态和细胞间神经纤维、血管相比较均无明显变化和差别。透射电镜下各组背根神经节的细胞数、细胞大体形态、胞膜和节内神经纤维相比较均无明显变化和差别,但胶原酶手术组背根神经节细胞胞内细胞器超微结构与正常对照组和相应生理盐水手术组比较有差别,表现为核仁部分偏向一侧、线粒体大量肿胀,部分嵴断裂和空泡形成。光镜病理和透射电镜均未见节细胞成群细胞坏死、细胞膜早期破裂和凋亡小体形成。【结论】临床应用的胶原酶化学髓核溶解术的胶原酶治疗浓度对大鼠脊神经背根神经节细胞有损伤作用。在临床工作中一定要慎重使用胶原酶的用药剂量和浓度,才能提高胶原酶应用的安全性。

[Objective] To study the morphological and pathologic effects of collagenase on dorsal root ganglion (DRG) in rats. [Methods] Fifty-seven male and healthy Sprague-Dawley rats were randomized into 7 groups: normal group, acute collagenase group, subacute collagenase group, chronic collagenase group, acute saline group, subacute saline group, and chronic saline group. The left fifth lumbar DRG was exposed in each rat. One milliliter of collagenase solution (300 U) was carefully applied to the exposed DRG in collagenase groups, and one milliliter of isotonic saline was applied to the exposed DRG in saline groups. The morphology of DRG under light microscope and electron microscope was analyzed 1 hour, 1 week, and 1 month after operation. [Results] The morphology of cells, the nucleolus, membrane and cytoplasm of neurons in DRG had not been changed under light microscope and electron microscope in all groups. The same was true of the nerve fibers and blood vessels in DRG. The differences of the ultrastructure of neurons in DRG between the collagenase groups and the normal group or the saline groups were significant. The nucleolus did not locate at the middle part of the nucleus in some cells. It had been observed in many cells with mitochondria swelling, loss of mitochondria crest, vesicle mitochondria and endoplasmic reticulum swelling. Karyotheca was rough in some cells. Cytoclasis and apoptosis of neurons had not been observed under light microscope and electron microscope. [Conclusion] The ultrastructure of neurons in dorsal root ganglion observed under electron microscope showed that collagenase used clinically did a certain extent damage to the neurons in DRG. So, the dosage and concentration of collagenase should be carefully applied when it is used for chemonucleolysis.