孤啡肽对内脏高敏感模型大鼠跨器官交叉内脏痛觉过敏的影响

目的 观察内脏高敏感状态下鞘内注射孤啡肽对跨器官交叉内脏痛觉过敏的影响.方法 成年雌性Sprague-Dawley大鼠44只,采用鸡卵清蛋白基础致敏联合结直肠芥末油灌注方法建立跨器官交叉-内脏痛觉过敏大鼠模型,并分为对照组(14只,造模+鞘内注射0.9%氯化钠溶液)、模型组(14只,造模)和孤啡肽组(16只,造模+鞘内注射孤啡肽).记录梯度膀胱扩张刺激(0.5～2.0 ml,20 s)时的腹壁内脏运动反射(VMR)肌电图,评估鞘内注射孤啡肽对结直肠芥末油灌注诱导的跨器官交叉-内脏痛觉过敏的影响.采用连续膀胱灌注测压法研究孤啡肽对结直肠芥末油灌注诱导的膀胱功能紊乱的影响.结果 行1.0、1.5、2.0 ml膀胱扩张刺激时,模型组扩张期与基线期肌电活动曲线下面积的差值明显高于对照组(P值分别=0.006、0.015和0.0331);在1.5和2.0ml时,孤啡肽组的差值则较模型组明显降低(P值分别=0.016和0.031).与对照组比较,模型组大鼠呈现膀胱功能紊乱,最大尿流压力显著降低、尿流频率显著增高(P值均＜0.01),孤啡肽组与模型组比较则最大尿流压力显著增高、尿流频率显著降低(P值均＜0.01).结论 鸡卵清蛋白基础致敏联合结直肠芥末油灌注可成功建立跨器官(直肠-膀胱)交叉内脏痛觉过敏大鼠模型.在内脏高敏感状态下,孤啡肽可在脊髓水平对芥末油灌注诱导的跨器官交叉内脏痛觉过敏及膀胱功能紊乱起到明显的调节及抗内脏伤害作用.

Effects of nociceptin/orphanin FQ on cross-organ sensitization in rat model with visceral hypersensitivity

Objective To investigate the effect of nociceptin/orphanin FQ (N/OFQ) on crossorgan sensitization and bladder function disorders in rat model with visceral hypersensitivity. Methods The model of cross-organ sensitization was induced by basic OVA-sensitization combined with colon mustard oil instillation in 44 female SD rats. All rats were then divided into control group (n= 14,infusion with 0.9% NaCl solution), model group (n= 14) and N/OFQ group (n= 16, infusion with N/OFQ). The anti-nociceptive effect of N/OFQ were evaluated by using the visceromotor response (VMR) to grade bladder distention (0. 5～2.0 ml, 20 s). Bladder function was evaluated with the cystometry by measuring voiding pressure and micturition frequency. Results The rats in model group had a significant increase of VMR response at 1.0 ml, 1.5 ml and 2.0 ml of pressure when compared to those in control group (P=0. 006,0. 015 and 0. 0331, respectively). However, N/OFQ treatment was able to reverse the increased VMR response in N/OFQ group at 1.5 ml and 2.0 ml of pressure (P=0. 016 and 0. 031, respectively). It was showed that mustard oil significantly reduced bladdervoiding pressure (P＜0. 01) and significantly increased micturition frequency (P＜0.01)in model group when compared to control group. The N/OFQ reversed the decrease of voiding pressure (P=0. 0038) and the increase of micturition frequency in N/OFQ group( P = 0. 001). Conclusions These findings indicate that the rat model of cross-organ sensitization was able to be established successfully by the basic OVA-sensitization combined with colon mustard oil instillation. N/OFQ has an antinociceptive effect on cross-organ hypersensitivity and attenuates changes in bladder urodynamic function.