Zinck N D T, Rafuse V F, Downie J W
Department of Pharmacology, Dalhousie University, Sir Charles Tupper Medical Building, 5850 College Street, Halifax, Nova Scotia, Canada B3H 1X5.
Exp Neurol. 2007 Apr;204(2):777-90. doi: 10.1016/j.expneurol.2007.01.011. Epub 2007 Jan 23.
Spinal cord injury (SCI) severely disrupts bladder function. What mediates bladder dysfunction after SCI is currently unknown. We investigated the role that primary afferent sprouting in lumbosacral cord may play in emergence of bladder activity after complete spinal cord transection. Rats had a bladder cannula chronically implanted. They were then subjected to complete surgical spinal cord transection at T9/T10. Cystometrographic analysis (0.1 ml/min) after injury revealed that bladder activity emerged in the form of nonvoiding contractions in all rats at approximately 5 days post transection. At 10-14 days after transection nonvoiding contractions remained and voiding contractions emerged that had increased maximal pressures (12-41 vs. 24-57 cmH(2)O) but were less efficient (6-15% vs. 79-100%) when compared to control implanted rats. We looked for sprouting 3 days and 8 days post transection, timepoints preceding the emergence of nonvoiding and voiding contractions respectively. Increases in CGRP density and distribution were seen in L6 and S1 spinal cord within lamina groupings of II-IV, V and VI, as well as lamina X at 8 days post transection. This increase remained in most lamina at 21 days post transection. Colocalization with the growth cone marker Gap-43 3 days and 5 days post transection at the level of the lumbosacral preganglionic nucleus verified that CGRP positive afferents were sprouting in L6/S1 spinal cord prior to emergence in bladder activity. These data provide support for the hypothesis that primary afferent sprouting contributes to emergence of bladder activity after spinal cord transection.
脊髓损伤（SCI）会严重破坏膀胱功能。目前尚不清楚SCI后介导膀胱功能障碍的因素。我们研究了腰骶部脊髓初级传入纤维芽生在完全性脊髓横断后膀胱活动出现过程中可能发挥的作用。给大鼠长期植入膀胱插管。然后在T9/T10水平对其进行完全性手术脊髓横断。损伤后膀胱内压描记分析（0.1 ml/分钟）显示，所有大鼠在横断后约5天出现以非排尿性收缩形式的膀胱活动。横断后10 - 14天，非排尿性收缩持续存在，并且出现了排尿性收缩，其最大压力增加（12 - 41 vs. 24 - 57 cmH₂O），但与植入对照的大鼠相比效率较低（6 - 15% vs. 79 - 100%）。我们在横断后3天和8天寻找芽生情况，这两个时间点分别先于非排尿性和排尿性收缩的出现。横断后8天，在L6和S1脊髓的II - IV层、V层和VI层以及X层的板层分组内观察到降钙素基因相关肽（CGRP）密度和分布增加。这种增加在横断后21天在大多数板层中仍然存在。在腰骶部节前核水平横断后3天和5天与生长锥标记物生长相关蛋白43（Gap - 43）共定位，证实CGRP阳性传入纤维在膀胱活动出现之前就在L6/S1脊髓中芽生。这些数据为初级传入纤维芽生有助于脊髓横断后膀胱活动出现这一假说提供了支持。
