Department of Urology, China Rehabilitation Research Centre, Rehabilitation School of Capital Medical University, Beijing, China.
Center of Neural Injury and Repair, Beijing Institute for Brain Disorders, Beijing, China.
Neurourol Urodyn. 2018 Nov;37(8):2462-2469. doi: 10.1002/nau.23724. Epub 2018 Jun 4.
To examine the roles of opioid receptors in the inhibition of nociceptive and nonnociceptive bladder reflexes by sacral dorsal root ganglion (DRG) stimulation in cats.
Hook electrodes were placed in the right S1 and S2 DRG of cats. The bladders were infused with physiologic saline or 0.25% acetic acid (AA). Naloxone (0.1, 0.3, and 1 mg/kg), an opioid receptor antagonist, was administered intravenously. S1 or S2 DRG stimulation was applied before and after administering the drug. Multiple cystometrograms were performed to determine the effects of DRG stimulation and opioid receptors on the micturition reflex under nociceptive and non-nociceptive conditions.
AA significantly (P < 0.01) reduced bladder capacity (BC). DRG stimulation at threshold (T) and 1.5 T significantly increased BC of the saline control under nociceptive and non-nociceptive conditions. When saline was infused, naloxone (0.1-1 mg/kg) significantly (P < 0.01) reduced BC; however, naloxone did not change BC during AA irritation. During saline infusion, naloxone (0.3 and 1 mg/kg) partly blocked S1 DRG stimulation-induced inhibition but had only a slight effect on S2 DRG stimulation. During AA infusion, naloxone (0.3 and 1 mg/kg) only partially blocked S1 DRG stimulation at T intensity but not during 1.5 T stimulation. However, no doses of naloxone significantly affected S2 DRG stimulation.
Opioid receptors play a role in sacral DRG stimulation on non-nociceptive condition but are not involved in the inhibitory effect of stimulation in nociceptive conditions.
观察骶神经根节（DRG）刺激对猫伤害性和非伤害性膀胱反射抑制的作用，探讨阿片受体的作用。
在猫右侧 S1 和 S2 DRG 放置钩状电极。膀胱输注生理盐水或 0.25%醋酸（AA）。静脉注射阿片受体拮抗剂纳洛酮（0.1、0.3 和 1mg/kg），给药前后进行 S1 或 S2 DRG 刺激。多次进行膀胱测压，以确定 DRG 刺激和阿片受体在伤害性和非伤害性条件下对排尿反射的影响。
AA 显著（P<0.01）降低膀胱容量（BC）。在伤害性和非伤害性条件下，阈值（T）和 1.5T 的 DRG 刺激显著（P<0.01）增加了生理盐水对照的 BC。当输注生理盐水时，纳洛酮（0.1-1mg/kg）显著（P<0.01）降低了 BC；然而，纳洛酮在 AA 刺激时并未改变 BC。在生理盐水输注期间，纳洛酮（0.3 和 1mg/kg）部分阻断了 S1 DRG 刺激引起的抑制，但对 S2 DRG 刺激仅有轻微影响。在 AA 输注期间，纳洛酮（0.3 和 1mg/kg）仅部分阻断了 T 强度的 S1 DRG 刺激，但对 1.5T 刺激无影响。然而，纳洛酮的任何剂量均未显著影响 S2 DRG 刺激。
阿片受体在骶神经根节刺激非伤害性条件下发挥作用，但在伤害性条件下刺激的抑制作用中不参与。
