Signal transdaction and gene expression in the pors associated with the overactive bladder following cerebra-vascular disease

目的：探讨脑梗死后脑桥被盖区（PTA）与膀胱过度活动的信号转导及分子机制。方法：SD大鼠左大脑中动脉闭塞（MCAO）诱导脑梗死。用连续输注膀胱造影监测清醒大鼠膀胱活动。检测H-89（蛋白激酶A抑制剂）、放线菌素D （RNA合成抑制剂）或NS-398 （COX-2抑制剂）对膀胱活性和基因（c-fos和zif268）表达的影响。实时荧光定量PCR检测DPT中c-fos和zif268 mRNA的表达。结果：脑梗死（CI）大鼠经载药预处理后，MCAO后膀胱容量（BC）显著降低，一直低于闭塞前容量的一半。在MCAO后2小时给予H-89，可抑制BC的减少。ACD也阻断了CI大鼠BC的减少。在acd治疗的CI大鼠中，BC逐渐恢复，并在10小时内恢复到MCAO前的对照水平。在MCAO前用NS-398治疗可以剂量依赖性地阻止膀胱过度活动的发展，并且不影响梗死体积。MCAO后1 h， c-fos、COX-2 mRNA表达，MCAO后3 h，与假手术大鼠相比，zif268 mRNA表达显著升高。谷氨酸能NMDA受体拮抗剂MK-801预处理可抑制膀胱过度活动的发生，并显著降低这些基因在PTA中的表达。ACD在MCA闭塞后1小时抑制c-fos mRNA表达的增加，MCAO后3小时抑制zif268表达的增加。结论：MCAO后膀胱过度活动的发生是由NMDA受体激活和RNA合成介导的。DPT的转录被发现是维持脑梗死引起的长期膀胱过度活动所必需的。此外，COX-2在大脑中的分子机制似乎与膀胱过度活动有关。进一步研究大脑中与膀胱过度活动相关的分子机制可能会导致针对排尿中枢的药物治疗。少

Object: To investigate the signal transduction and molecular mechanisms in the pontine tegmental area (PTA) associated with bladder overactivity after cerebral infarction. Methods: Cerebral infarction was induced by left middle cerebral artery occlusion (MCAO) in SD rats. Bladder activity was monitored with continuous infusion cystometrography in awake rats. The influences of H-89 (protein kinase A inhibitor), actinomycin D (ACD; RNA synthesis inhibitor), or NS-398 (COX-2 inhibitor) on bladder activity and gene expression (c-fos and zif268) were examined. Expressions of c-fos and zif268 mRNA in the DPT were monitored with real-time PCR. Results: In cerebral infarcted (CI) rats pretreated with vehicle, bladder capacity (BC) was significantly reduced after MCAO and remained consistently below half of pre-occlusion capacity. H-89, when administered 2 hours after MCAO, inhibited the reduction in BC. ACD also blocked reduction in BC in CI rats. In ACD-treated CI rats, BC gradually recovered … More and returned to the control level prior to MCAO within 10 hours. Treatment with NS-398 before MCAO prevented the development of bladder overactivity dose-dependently, and did not influence infarction volume. One hour after MCAO, c-fos and COX-2 mRNA expression, three hours after MCAO, zif268 mRNA expression had significantly increased as compared to those in sham operated rats. Pretreatment with MK-801, glutamatergic NMDA receptor antagonist, inhibited the development bladder overactivity and significantly reduced these gene expressions in the PTA. ACD suppressed an increase in c-fos mRNA expression 1hour after MCA occlusion as well as in zif268 3hours after MCAO. Conclusion: These results indicate that the development of bladder overactivity following MCAO is mediated by the activation of an NMDA receptor and by an RNA synthesis. Transcription in the DPT was found to be necessary for maintenance of long-lasting bladder overactivity caused by cerebral infarction. Furthermore, COX-2 molecular mechanism in the brain seems to be related to bladder overactivity. Further research on the molecular mechanisms in the brain related to bladder overactivity may lead to pharmacological therapy which targets the micturition center. Less