兔坐骨神经嵌压后病理改变与离子变化的实验研究

Experimental study of demyelination and the changes of calcium, potassium and sodium in compressed sciatic nerve of rabbits

目的：探讨周围神经嵌压后病理形态改变及离子含量变化与压力的关系。方法：新西兰大白兔２０只，按压力大小分为０ｋＰａ、４ｋＰａ、８ｋＰａ、１２ｋＰａ４组。将双坐骨神经游离后从神经压迫器的孔隙内通过，持续加压１ｈ后解除压迫，术后１周取材，制作病理切片和神经单丝纤维撕梳，行组织形态学观察。ＧＧ－Ｘ原子吸收分光法测定各压力组坐骨神经内钾、钠、钙等元素的含量。结果：各压力组神经受压段和气囊两端粗神经纤维均发生不同程度的节段性脱髓鞘改变，神经的远端脱髓鞘不明显；不同压力作用下的受压神经段Ｋ＋、Ｎａ＋、Ｃａ２＋等含量均有不同变化。结论：不同压力作用下受压神经段均发生不同程度节段性脱髓鞘改变，其程度与压力成正比；受压神经组织Ｋ＋、Ｎａ＋、Ｃａ２＋浓度升高与压力高低呈正相关；

Objective:To study demyelination with the changes of calcium, potassium and sodium in compressed sciatic nerve Methods:Acute, graded nerve compression was applied to the sciatic nerves of adult rabbits in whom an inflatable miniature plexiglas compression device had been implanted in the both side sciatic nerves The external pressure of 0、4、8、12 kPa were used to compress nerves for 1 hour Nerves were excised at 7 days, 2 u m thickens transverse sections and teased fibers were made Used absorbedatomic spectrum to do K +,Na +,Ca  quantity analysis Results:The demyelination was the predominant lesion in nerves subjected to pressure and was commonly present in nerves aroun which the compression chamber remained uninflated The levels of calcium, potassium and sodium in compression nerve segments were significantly elevated over control values Conclusion:The degrade of demylination and calcium, potassium and sodium in compression nerve segments were in right proportion to presser The demylination was unremarkable far from the injured position of nerves The ion imbalance may caused the secondary nerves injuries