Bolam J M, Robinson C J, Hofstra T C, Wurster R D
J Auton Nerv Syst. 1986 Aug;16(4):261-77. doi: 10.1016/0165-1838(86)90033-0.
Micturition difficulties appear as an often-reported side effect of the clinical use of opiates for spinal analgesia. Only a few experimental studies have focused specifically on this problem, especially in an unanesthetized animal model where chronic pharmacological studies can be carried out. The changes in micturition volume thresholds that occurred following spinal intrathecal injections of 1 mg of morphine sulphate were measured in 11 conscious dogs and compared with threshold changes produced in these same dogs by i.v. injections of various doses of morphine sulphate and by intrathecal and i.v. injections of naloxone HCl. In all cases, intrathecal or systemic morphine at doses of 1.0 mg or greater significantly (P less than 0.05) increased the bladder volume at which micturition took place. Naloxone, injected intrathecally to reverse the effects of intrathecal morphine, significantly reduced the micturition volume threshold, in most cases to below control volumes. A 400 microgram dose of naloxone, injected intrathecally without prior injection of morphine, significantly lowered the volume threshold in 9 dogs, even though two of these dogs had elevated thresholds following naloxone injection. The reduction in volume thresholds by i.v. naloxone not preceded by morphine injection was not statistically significant over that of control. These results are interpreted in light of recent findings concerning localization of endogenous opiate receptors within the micturition reflex pathway.
排尿困难是临床使用阿片类药物进行脊髓镇痛时经常报告的副作用。只有少数实验研究专门关注了这个问题，特别是在可以进行慢性药理学研究的未麻醉动物模型中。在11只清醒的狗身上测量了鞘内注射1毫克硫酸吗啡后排尿量阈值的变化，并将其与这些狗静脉注射不同剂量硫酸吗啡以及鞘内和静脉注射盐酸纳洛酮所产生的阈值变化进行了比较。在所有情况下，鞘内或全身注射1.0毫克或更高剂量的吗啡会显著（P小于0.05）增加排尿时的膀胱容量。鞘内注射纳洛酮以逆转鞘内吗啡的作用，在大多数情况下会显著降低排尿量阈值，使其低于对照容量。在未预先注射吗啡的情况下，鞘内注射400微克剂量的纳洛酮，在9只狗中显著降低了容量阈值，尽管其中两只狗在注射纳洛酮后阈值升高。在未预先注射吗啡的情况下，静脉注射纳洛酮导致的容量阈值降低与对照相比没有统计学意义。根据最近关于内源性阿片受体在排尿反射途径中的定位的研究结果对这些结果进行了解释。
