Exercise training improves erectile dysfunction in diabetes: role of central mech

描述（由申请人提供）：勃起功能障碍是糖尿病的一种严重而常见的并发症。除了身体平滑肌放松的外周作用外，参与中枢机制的交感神经和副交感神经的激活也负责阴茎勃起。我们的研究表明：1)STZ诱导的I型糖尿病（T1D）大鼠对中央给药n -甲基- d -天冬氨酸（NMDA）的勃起反应减弱，2)NMDA诱导的勃起是一氧化氮（NO）介导的，3)T1D大鼠PVN中的神经元NO合成酶（nNOS）减少，4)特异性替换PVN中的nNOS（通过腺病毒介导的基因转移）恢复NMDA诱导的T1D大鼠勃起。5) T1D大鼠血浆血管紧张素II （Ang II）水平升高，PVN中Ang II型1 （AT1）受体水平上调；6)Ang II通过活性氧（ROS），特别是超氧化物（O2-）机制调节自主神经外流；7)Ang II下调培养神经元细胞的nNOS。我们实验室获得的令人兴奋的初步结果表明，运动训练（ExT）可显著改善中枢nmda诱导的T1D勃起反应。基于这些有趣的初步数据和之前的工作，本项目将试图解决ExT通过调节PVN中的NO和Ang II-O2信号通路改善T1D大鼠中央性NMDA诱导的勃起功能障碍的假设。在Aim 1中，我们将确定ExT对T1D大鼠中枢性nmda - no诱导的勃起功能障碍的影响。在Aim 2中，我们将确定Ang II在T1D大鼠中枢NMDA-NO诱导的勃起功能障碍中的作用。在Aim 3中，我们将通过刺激O2-来确定增强的Ang II是否有助于nmda - no诱导的T1D大鼠勃起功能障碍。在Aim 4中，我们将通过对T1D大鼠PVN中Ang II-O2-信号的作用来确定ExT是否对中枢性nmda - no诱导的勃起功能障碍有有益作用。这些目标将在T1D大鼠中使用整个动物到细胞水平的互补方法来解决；勃起功能的生理测量，清醒和麻醉动物PVN的显微注射，腺病毒基因转染，O2-和NO代谢物测量，免疫组织化学，使用实时PCR和Western blot测量特定脑核内蛋白质的分子生物学技术来测量mRNA信息。这些研究的成功完成将提供关于中枢机制的重要新信息，特别是在下丘脑PVN内，参与改变勃起功能的神经调节，以及ExT对T1D勃起功能障碍的治疗益处。了解中枢机制在神经驱动改变中的作用（迄今为止研究不多）将提高我们治疗糖尿病性功能障碍的能力。公共卫生相关性：勃起功能障碍是糖尿病的一种严重和常见的并发症。糖尿病患者勃起功能障碍的机制包括外周和中枢异常。然而，在男性糖尿病患者中，西地那非（伟哥）似乎仅对50%的患者在阴茎水平上有治疗作用。拟议的研究应提供重要的新信息，涉及改变勃起功能的神经调节的中枢机制和运动训练对糖尿病患者勃起功能障碍的治疗益处。了解中枢机制在神经驱动改变中的作用（迄今为止研究不多）将提高我们治疗糖尿病性功能障碍的能力。

DESCRIPTION (provided by applicant): Erectile dysfunction is a serious and common complication of diabetes mellitus. Apart from peripheral actions of corporal smooth muscle relaxation, the activation of sympathetic and parasympathetic nerves involved central mechanisms are also responsible for penile erection. We have shown that 1) in rats with streptozotocin (STZ)-induced type I diabetes (T1D) the erectile response to central administrated N-methyl-D-aspartic acid (NMDA) in the PVN is blunted, 2) NMDA-induced erection is nitric oxide (NO)-mediated, 3) neuronal NO synthase (nNOS) in the PVN of T1D rats is reduced, 4) replacing nNOS specifically in the PVN (via adenoviral-mediated gene transfer) restores the NMDA- induced erection in T1D rats, 5) plasma levels of angiotensin II (Ang II) are increased and Ang II type 1 (AT1) receptors in the PVN are up-regulated in T1D rats, 6) Ang II modulates autonomic outflow via a reactive oxygen species (ROS), particularly superoxide (O2-) mechanism, 7) Ang II down-regulates nNOS in cultured neuronal cells. Exciting preliminary results obtained in our laboratory suggest that exercise training (ExT) dramatically improves central NMDA-induced erectile response in T1D. Based on these intriguing preliminary data and previous work, the present project will attempt to address the hypothesis that ExT improves central NMDA- induced erectile dysfunction in T1D rats by regulating NO and Ang II-O2- signaling pathways in the PVN. In Aim 1 we will determine the impact of ExT on central NMDA-NO-induced erectile dysfunction in T1D rats. In Aim 2 we will determine the contribution of Ang II to central NMDA-NO- induced erectile dysfunction in T1D rats. In Aim 3 we will determine if the enhanced Ang II contributes to central NMDA-NO-induced erectile dysfunction in T1D rats via stimulation of O2-. In Aim 4 we will determine if ExT has beneficial effects on central NMDA-NO-induced erectile dysfunction through the actions on Ang II-O2- signaling in the PVN of T1D rats. These aims will be addressed in T1D rats using complementary methodologies in the whole animal to the cellular level; physiological measurement of erectile function, microinjection of the PVN in conscious and anesthetized animals, adenoviral gene transfection, O2- and NO metabolite measurements, immunohistochemistry, molecular biology techniques to measure mRNA message using real time PCR and Western blot to measure the protein within specific brain nuclei. The successful completion of the proposed studies should provide significant new information regarding the central mechanisms, specifically within the PVN of the hypothalamus, involved in altered neural regulation of erectile function and the therapeutic benefits of ExT on erectile dysfunction in T1D. Understanding the role of central mechanisms, (not much studied to date), in the altered neural drive would enhance our ability to treat the diabetic sexual dysfunction. PUBLIC HEALTH RELEVANCE: Erectile dysfunction is a serious and common complication of diabetes mellitus. The proposed mechanisms for erectile dysfunction in diabetes include both peripheral and central abnormalities However, in diabetic male patients sildenafil (Viagra) appears to be therapeutic only in 50% of the patients at the level of the penis. The proposed studies should provide significant new information regarding the central mechanisms involved in altered neural regulation of erectile function and the therapeutic benefits of exercise training on erectile dysfunction in diabetes. Understanding the role of central mechanisms, (not much studied to date), in the altered neural drive would enhance our ability to treat the diabetic sexual dysfunction.