大鼠脊髓损伤后膀胱生理反射弧重建动物模型的实验研究

目的 建立大鼠人工生理膀胱反射弧动物模型,同时修复重建膀胱的感觉与运动功能,为观测该反射通路重建排尿功能的修复效果奠定基础.方法 选用20只体重280～300 g的成年雄性SD大鼠,随机分为2组,每组10只.A组为L6前、后根分别与S前、后根端端吻合造模;B组为L6神经根总干与S2神经根总干端端吻合造模.术中显微解剖测量各神经根的外径,L6与S2脊神经根间的距离及L6的可分离长度.术后观察大鼠排尿情况及下肢活动情况,并行BBB评分.术后2周取材对各神经根行Fast Blue染色,行神经纤维计数.结果 于L6椎体平面,L6神经根总干及其前、后根外径分别为(1.54±0.33)、(0.68±0.13)、(0.88±0.10)mm;S2神经根总干及其前、后根外径分别为(1.39±0.42)、(0.62±0.08)、(0.79±0.14)mm.L6神经根可分离长度为(10.76±2.11)mm;L5、L6神经合干处与S2椎间孔间的距离为(14.21±1.95)mm.两组模型均可无张力吻合.各组大鼠均存活,术后排尿、排便与术前无异.A组术前、术后BBB评分为(20.20±0.35)、(19.80±0.23)分;B组为(20.20±0.35)、(19.20±0.31)分,组间差异无统计学意义(P＞0.05).L6、S2神经根总干的神经纤维为(892±32)、(788±29)根;L6、S2脊神经前、后根神经纤维分别为(354±26)、(532±17)、(325±19)、(478±22)根,组间差异均无统计学意义(P＞0.05).结论 将大鼠L6前、后根分别与S2前、后根端端吻合造模,操作简便易行、可重复性好,且能重建完整的人工膀胱反射弧,是一种较理想的膀胱生理反射弧重建的动物模型.

EXPERIMENTAL STUDY ON RECONSTRUCTION OF PHYSIOLOGICAL REFLEX ARC AFTER MEDULLARY CONE INJURY IN RATS

OBJECTIVE: To establish the animal model of the artificial physiological reflex arc with the reconstruction of the sensory and the motorial functions of atonic bladder simultaneously in the rats, and to provide the foundation to further investigate the repairing effectiveness of this technique. METHODS: There were 20 adult male SD rats (weighing 280-300 g) which were randomly divided into 2 groups (n = 10): group A and group B. Group A was anastomosis of the ventral roots (VR) and the dorsal roots (DR) between L6 and S2 simultaneously to establish the model of the artificial physiological reflex arc. Group B was anastomosis of the main trunk between L6 and S2 to establish the model. The contents of the observation included: (1) To measure the external diameter of the VR, DR and the main trunk of L6 and S2 with the sliding caliper; and to measure not only the distance between L6 and S2 but also the separable length of L6 with the ruler. (2) Fast Blue dyeing of the VR, DR and the main trunk of L6 and S2 was performed to count their nerve fibers assisted by the Leica FW4000 system 2 weeks after opertation. (3) The observation of the urination of the rat and BBB scoring to evaluate the motorial function of the lower limbs was performed postoperatively. RESULTS: (1) L6 located in the lateral side of the S1-4 in the vertebral body of L6. The external diameters of the VR, DR and the main trunk of L6 were (0.68 +/- 0.13), (0.88 +/- 0.10) and (1.54 +/- 0.33) mm, respectively, while those of S2 were (0.62 +/- 0.08), (0.79 +/- 0.14) and (1.39 +/- 0.42) mm, respectively. The distance between L6 and S2 was (14.21 +/- 1.95) mm, and the separable length of L6 was (10.76 +/- 2.11) mm. Furthermore, the microdissection indicated the VR and the DR between L6 and S2 could be anastomosed respectively with no-tension at the level of the vertebral body of L6; and the main trunk of L6 and S2 could be anastomosed with no-tension at the level of the confluens of L5,6. (2) With Fast Blue dyeing, there were 892 +/- 32, 354 +/- 26 and 532 +/- 17 nerve fibers of the VR, DR and the main trunk of L6, respectively. And there were 788 +/- 29, 325 +/- 19, and 478 +/- 22 nerve fibers of the VR, DR and the main trunk of S2, respectively. There were no volar ulcer, trichomadesis and self-eating of the affected limbs in the both groups postoperatively. The urinations of the rats after operation were not different from those before operation. The mean BBB scores of pre- and postoperation in group A were 20.20 +/- 0.35 and 19.80 +/- 0.23, respectively; the mean BBB scores of pre- and postoperation in group B were 20.20 +/- 0.35 and 19.20 +/- 0.31, respectively. There was no significant difference of the above indexes between group A and group B (P > 0.05). CONCLUSION: Anastomosis of the VR and the DR between L6 and S2 simultaneously in rats is an ideal animal model to establish the artificial physiological reflex arc owing to its simple and reproducible procedures.