GENDER RELATED DIFFERENCE IN VISCERAL SENSITIVITY IN IBS

描述：根据临床研究，女性比男性更有可能 经历各种慢性、复发性内脏疼痛综合征， 间质性膀胱炎或肠易激综合征（IBS）。但在 与动物模型中充分表征的性别差异相反， 实验证据支持人类疼痛的性别差异 认识仍不明确，机制仍不清楚。 可能造成性别差异的潜在机制 内脏痛的知觉包括大脑的固定性二态性 与伤害性刺激的中枢处理有关的区域，以及 中枢疼痛处理的短暂性神经系统相关周期性调节剂。 由于女性比男性更容易经历骨盆疼痛， 内脏在交配，怀孕和劳动，这是假设， 女性在至少两种类型的潜在反应中表现出差异， 盆腔器官产生的有害感觉： 内源性疼痛抑制系统和改变的注意力过程 包括高度警惕在目前的提案中，调查人员将 通过确定与性别有关的差异来检验一般假设， 在健康对照受试者和IBS患者中使用H21502 PET成像， 大脑连同知觉、自主神经和 直肠乙状结肠刺激的神经内分泌反应。他们将 利用两个内脏刺激范式的基础上以前的工作，一个测试 乙状结肠条件反射引起的内脏敏感化， 对预期的高强度和低强度内脏的预期反应 感觉。这将允许直接比较知觉和感觉 IBS中的性别相关因素。调查人员还将分别 检查稳定的非激素因素（口服避孕药的女性）， 激素因素（在排卵期妇女在黄体期， 围月经期）。

DESCRIPTION: Based on clinical studies, women are more likely than men to experience a variety of chronic, recurrent visceral pain syndromes such as interstitial cystitis or irritable bowel syndrome (IBS). However, in contrast to well-characterized sex differences in animal models, experimental evidence to support gender differences in human pain perception remains inconclusive and mechanisms remain poorly understood. Potential mechanisms that may underlie gender-related differences in perception of visceral pain included fixed sexual dimorphism of brain regions concerned with central processing of noxious stimuli, and transient hormone-related cyclic modifiers of central pain processing. Since women are more likely than men to experience pain affecting pelvic viscera during copulation, pregnancy and labor, it is hypothesized that women exhibit differences in at least two type of responses to potential harmful sensations arising from the pelvic organs: altered activation of endogenous pain inhibition systems and altered attentional processes including hyper-vigilance. In the current proposal, the investigators will test the general hypothesis by determining gender-related differences in healthy control subjects and in IBS patients using H21502 PET imaging of the brain together with measurement of perceptual, autonomic, and neuroendocrine responses to noxious rectosigmoid stimulation. They will utilize two visceral stimulus paradigms based on previous work, one tests visceral sensitization from sigmoid colon conditioning and the other anticipatory responses to expected high and low intensity visceral sensation. This will allow for direct comparison of perceptual and sensory gender-related factors in IBS. The investigators will also separately examine stable, non-hormonal factors (in women on oral contraceptives) and hormonal factors (in ovulating women during the luteal and perimenstruation periods).