轴突损伤距离对成年金黄地鼠视网膜节细胞轴突在正常或预先溃变周围神经移植物中再生的影响

目的　系统研究轴突损伤的距离与轴突再生之间的关系 ,以及预先溃变周围神经移植物对视网膜节细胞 (简称节细胞 )轴突在不同距离损伤后再生的影响。　方法　在距成年金黄地鼠眼球后极 0 .5、1、1.5、2、3或7m m处切断左侧视神经 ,视神经眶侧断端同正常 (正常组 )或预先溃变 (溃变组 )的周围神经移植物相吻合。　结果　移植术后 2 8d,两组荧光金逆行标记的发出再生轴突的节细胞数量均随轴突损伤距离的增加而下降 ,并以 0 .5～3m m距离点之间下降最为明显。比较两组对应距离点 ,溃变组标记节细胞数量在 2、3mm距离点较正常组显著增多。　结论　成年金黄地鼠节细胞轴突损伤的距离 ,决定了发出再生轴突的节细胞数量。预先溃变周围神经移植物对节细胞轴突再生具有促进作用 ,并以轴突损伤距离为条件。

EFFECT OF DISTANCE OF AXOTOMY ON AXONAL REGENERATION OF RETINAL GANGLION CELLS INTO A NORMAL OR PRE-DEGENERATED PERIPHERAL NERVE GRAFT IN ADULT HAMSTERS

Objective The present study was carried out to examine the relationship between the distance of axotomy and axonal regeneration systematically,and the effect of a pre|degenerated peripheral nerve(PN) graft on axonal regeneration of retinal ganglion cells(RGCs) axotomized at different distances. Methods The optic nerve(ON) was transected at 0^5,1,1^5,2,3 or 7mm from the optic disc and a normal (the normal group) or pre|degenerated(the pre|degeneration group) PN graft was transplanted onto the ocular ON stump in adult hamsters. Results In both groups,the number of regenerating RGCs 28 days after grafting decreased significantly when the distance of axotomy increased from 0^5 to 7mm with a sharp decline between 0^5 and 3mm.When the corresponding distance points between the two groups were compared,enhanced regeneration was observed at 2 and 3mm in the pre|degeneration group. Conclusion These results show that the distance of axotomy on the ON of adult hamsters is critical in determining the number of regenerating RGCs.The beneficial effect of a pre|degenerated PN graft on axonal regeneration of axotomized RGCs is conditional on the distance of axotomy.;