活性氧在急性尿潴留大鼠膀胱功能损害中的作用研究

Roles of reactive oxygen species in acute retention bladder in rats

目的 探讨活性氧在急性尿潴留大鼠膀胱功能损害中的作用。方法 健康雌性Wistar大鼠分为 5组 (n =5 ) :正常对照组 (C组 ) ;其余 4组为实验组 ,并以 2倍于正常膀胱容量生理盐水过度充盈 2h ,分别于排空后 0h (E0组 )、排空后 1h (E1组 ) ,排空后 2h(E2组 )行充盈性膀胱测压和膀胱组织ATP酶活力与丙二醛 (MDA)含量测定 ;治疗组在膀胱排空前 10min心内注射过氧化物歧化酶 (SOD) 5 0 0U(SOD组 ,n =5 ) ,余处理同E2组。结果 膀胱过度充盈后其顺应性降低 ,不稳定收缩增多 (P <0 0 1)。ATP酶活力在排空后 1h显著降低 ,而MDA在排空后 1h上升至最高水平。膀胱排空前注射SOD ,MDA含量较E2组显著降低 ,膀胱功能显著改善 (P <0 0 1)。结论 活性氧在急性尿潴留对大鼠膀胱功能损害中起着重要作用 ,抗氧化剂可以保护活性氧对膀胱功能的损害作用。

Objective To investigate the roles of reactive oxygen species (ROS) in acute retention bladder in rats. Methods A total of 25 female Wistar rats were randomized into 5 groups: group 1 without overdistention (OD) (group C, n=5), group 2 with 2 h OD (group E0, n=5), group 3 with 2 h OD and 1 h recovery after emptying (group E1, n=5), group 4 with 2 h OD and 2 h recovery (group E2, n=5). Rats in group 5 with 2 h OD and 2 h recovery (group SOD, n=5) were injected with 500 U superoxide dismutase (SOD) through the cardiac ventricle at 10 min before emptying. Cystometrography was performed in pre-overdistention and post-emptying. Then bladders were excised and frozen in liquid nitrogen for determination of the activity of adenosine triphosphatase (ATPase) and concentration of malondialdehyde (MDA). Results The compliance of post-overdistention bladder decreased sharply as compared with that of the pre-overdistention and overdistention bladder, while frequency of over-activity was higher than that of the pre-overdistention and overdistention bladder. Furthermore, the activity of 3 kinds of ATPase in the bladder in group E1 reduced sharply. The concentration of MDA increased during overdistention period and early period of emptying and peaked at 1 h after emptying. After injection of superoxide dismutase, the concentration of MDA in group SOD bladder was lower than that in group E2 bladder. At the same time, the bladder function was improved. Conclusion ROS is a main factor contributing to injury of overdistention/ emptying bladder. Antioxidant can protect bladder function from injury of over-distention.