Neural Mechanisms of Gynecological Pain

描述（由申请人提供）：这个项目的长期目标是促进对女性慢性盆腔疼痛的神经机制的理解。目前的研究集中在子宫内膜异位症，一种由子宫内膜组织外生长定义的疾病。症状包括生育能力低下和严重的慢性疼痛，包括性交困难（阴道痛觉过敏）、痛经（月经疼痛）和其他盆腔和腹部内脏和肌肉疼痛。众所周知，这些疼痛很难缓解。阻碍更好治疗方法发展的一个主要因素是，异位生长和疼痛之间关系的潜在机制尚不清楚。存在一种大鼠子宫内膜异位症模型（ENDO），涉及子宫块腹动脉的自体移植。移植后形成囊肿，其特征与女性的异位生长相似。和女性一样，大鼠的生育能力较弱，并表现出阴道和腹部肌肉痛觉过敏。拟议的研究将使用这种大鼠模型来测试有关内啡肽诱导的阴道痛觉过敏机制的假设。最近的研究发现，在大鼠模型中，异位生长通过伸缩神经和迷走神经吸引神经供应，为研究异位生长与疼痛之间难以捉摸的联系提供了新的方向。Aim #1的三项研究将验证endo诱导的阴道亢进是由囊肿发育中的神经供应活动产生的中枢神经效应引起的假设。研究1-2将比较：(i)囊肿的神经供应（用神经元标记物免疫染色显示），（ii）神经供应的活性（通过蛋白质外渗漏评估），（iii）脊髓和脑干对阴道信息处理的变化（通过c-Fos和磷酸化的n -甲基- d -天冬氨酸受体NR1 [pNR1]蛋白的神经元表达评估），以及（iv）腹膜细胞因子的含量（使用蛋白质阵列）。通过评估阴道痛觉行为，研究3将验证这一预测，如果假设是正确的，在神经活动发展之前切除囊肿应该可以防止ENDO诱导的痛觉过敏的发展。Aim #2中的三项研究将检验endo诱导的阴道痛觉过敏的维持需要由囊肿的脊髓、脑干、节段间和/或椎管上作用的神经供应来维持的假设。通过行为学方法，研究1将检验这一假设的预测，即对完全生长的囊肿进行去神经处理应能减轻痛觉过敏。研究2将以不同的方式验证这一假设，通过评估完全生长囊肿的去神经支配如何影响阴道刺激诱导的脊髓和脑干神经元中c-Fos和pNR1的表达。研究3将通过评估脊髓横断如何影响阴道刺激诱导的c-Fos和pNR1在脊髓和脑干神经元中的表达来验证有关节段间和椎管上效应的假设。这些研究结果有可能提高对导致子宫内膜异位症疼痛的机制的理解，从而导致新的治疗策略。公共卫生相关性：子宫内膜异位症是育龄妇女常见的疾病，子宫外发现子宫组织异常生长，伴有严重疼痛，大大降低生活质量。部分原因是由于对异常生长如何引起这些疼痛知之甚少，众所周知，如果不诉诸激素或手术，这些疼痛很难缓解，要么产生难以忍受的副作用，要么不起作用。本申请中提出的研究将使用一个经过验证的啮齿动物模型来研究新发现的神经如何萌芽以供应异常生长可能影响中枢神经系统过程以诱导疼痛，从而提高可以导致改进治疗策略的知识。

Description (provided by applicant): The long-term goal of this program is to advance understanding of neural mechanisms of chronic pelvic pain in females. Current studies focus on endometriosis, a disorder defined by extrauteral growths of endometrial tissue. Symptoms include subfertility and severe chronic pains, including dyspareunia (vaginal hyperalgesia), dysmenorrhea (menstrual pain) and other pelvic and abdominal visceral and muscle pains. These pains are notoriously difficult to alleviate. A major factor impeding development of better treatments is that mechanisms underlying the relationship between the ectopic growths and pain are poorly understood. A rat model of endometriosis exists (ENDO) that involves autotransplantion on abdominal arteries of pieces of uterus. The transplants form cysts with characteristics similar to the ectopic growths in women. Like women, the rats are subfertile and exhibit vaginal and abdominal muscle hyperalgesia. The proposed studies will use this rat model to test hypotheses concerning mechanisms underlying ENDO-induced vaginal hyperalgesia. The recent discovery that the ectopic growths attract a nerve supply, via spanchnic and vagus nerves in the rat model, provides a new direction to study the elusive association between the ectopic growths and pain. Three studies in Aim #1 will test the hypothesis that development of ENDO-induced vaginal hyperalge- sia results from central neural effects produced by activity in the cysts' developing nerve supply. Studies 1-2 will compare developmental time courses of: (i) the cysts' nerve supply (visualized by immunostaining with neuronal markers), (ii) activity in the nerve supply (assessed by protein extravasation), (iii) changes in spinal and brainstem processing of vaginal information (assessed by neuronal expression of c-Fos and phosphory- lated N-methyl-D-aspartic acid receptor NR1 [pNR1] proteins), and (iv) peritoneal content of cytokines (using protein arrays). By assessing vaginal nociception behaviorally, Study 3 will test the prediction that, if the hy- pothesis is correct, removing cysts before nerve activity develops should prevent the development of ENDO- induced hyperalgesia. Three studies in Aim #2 will test the hypothesis that maintenance of ENDO-induced vaginal hyperalgesia requires maintenance by the cysts' nerve supply of spinal, brainstem, intersegmental and/or supraspinal effects. With behavioral methods, Study 1 will test the prediction from this hypothesis that denervating fully-grown cysts should reduce the hyperalgesia. Study 2 will test the hypothesis differently, by assessing how denervations of fully-grown cysts affect vaginal-stimulation induced c-Fos and pNR1 express- ion in spinal and brainstem neurons. Study 3 will test hypotheses concerning intersegmental and supraspinal effects by assessing how spinal transections affect vaginal-stimulation-induced c-Fos and pNR1 expression in spinal and brainstem neurons. Results of the studies have the potential for improving understanding of mechanisms that contribute to the pains of endometriosis, thereby leading to new treatment strategies. PUBLIC HEALTH RELEVANCE: Endometriosis is common disorder suffered by women of childbearing age in whom abnormal growths of uterine tissue found outside the uterus are associated with severe pains that greatly reduce quality of life. In part because so little is known about how the abnormal growths give rise to these pains, they are notoriously difficult to alleviate without resorting to hormones or surgery that either produce intolerable side effects or fail to help. Studies proposed in this application will use a validated rodent model to investigate how the newly- discovered nerves that sprout to supply the abnormal growths might influence central nervous system processes to induce the pains, thereby improving knowledge that can lead to improved treatment strategies.