自体静脉移植与胰岛素样生长因子-Ⅰ重建勃起反射通路的实验研究

Reconstruction of erectile reflex circuit by autologous vein graft combined with use of insulin-like growth factor-Ⅰ

目的 探讨自体静脉移植结合使用胰岛素样生长因子-Ⅰ(IGF-Ⅰ)重建勃起反射通路的可行性。方法 将48只雄性成年SD大鼠随机分成4组,每组12只。Ⅰ组:假手术组,只找到双侧海绵体神经(CN)即关闭切口;Ⅱ组:CN离断组,切除大鼠双侧CN约5 mm及其侧支;Ⅲ组:静脉移植+IGF-Ⅰ组,在Ⅱ组的基础上,用大鼠自体静脉移植桥接缺省的CN,并向移植静脉管腔内注射IGF-Ⅰ;Ⅳ组:静脉移植+生理盐水组,用等量的生理盐水代替Ⅲ组的IGF-Ⅰ。4个月后,阿朴吗啡试验评估大鼠的勃起功能;然后在大鼠阴茎海绵体内注射荧光金,对CN逆行追踪。结果 Ⅲ组的勃起率达92％(11/12),明显高于Ⅱ组(50％)和Ⅳ组(O％),P<0.01。荧光显微镜下计数,Ⅲ组盆神经节中荧光金阳性着色细胞数明显多于生理盐水组和CN切断组(P<0.01)。结论 自体静脉移植结合使用IGF-Ⅰ,是一种有效的治疗因CN损伤而致勃起功能障碍的新方法。

Objective To explore the feasibility of erectile reflex circuit reconstruction by autologous vein graft combined with the use of insulin-like growth factor- Ⅰ (IGF- Ⅰ ). Methods 48 male adult Sprague-Dawley rats were randomized into 4 groups of 12 rats; group Ⅰ ( sham-operation group) , undergoing operation to identify the bilateral cavernous nerves ( CNs) only; group Ⅱ ( bilateral CN ablation group) in which the bilateral CNs of the length of at least 5 mm were ablated; group Ⅲ ( vein graft plus IGF-Ⅰ group) in which the ablated CNs were repaired by autologous vein graft and IGF- I was injected into the venous cavity; and group Ⅳ (vein graft plus normal saline group) , in which the ablated CNs were repaired and normal saline was injected instead. Four months later, apomorphine test was performed on each rat, and the erection times during the following half hour were recorded. After that, 4% flluoro-gold was injected into the bilateral corpus cavernosum of penis for each rat after anesthesia. Five days later, the rats were sacrificed and their bilateral major pelvic ganglia were obtained for detection of flluoro-gold by fluorescent microscopy. Results Apomorphine test showed an erection rate of 92% in group Ⅲ, significantly higher than those of the group Ⅱ (0% ) and group Ⅳ (50% , both P <0. 01) , and close to that of the sham-operation group (100% , P > 0. 05 ). The average erection times of the group Ⅲ was (1.5 ± 0. 8 ) times, significantly more than those of the group Ⅱ and group Ⅳ [ (0. 0 ±0.0) times and (0.6 ±0.7) times respectively, both P < 0. 05] , but significantly less than that of the sham-operation group [ (2. 7 ±0.9) times, P <0. 05 ]. Five days after injection of fluoro-gold solution, the number of fluoro-god positively stained neural cells of the group Ⅲ was 86 ± 14, significantly more than those of the group Ⅱ (14 ±6) and group Ⅳ (46 ± 14, both P<0. 05) ,but significantly less than that of the sham-operation group ( 152 ± 36, P < 0. 05) . And the fluoro-gold stained neural cells of the group Ⅲ was brighter than those of the group Ⅱ and group Ⅳ , but not so bright as those of the sham operation group. Conclusion Reparation of ablated CNs by autologous vein graft combined with local injection of IGF- Ⅰ is a new effective method to treat ED following CN injury.