Estrogen and Sympathetically Mediated Vasoconstriction

雌激素和交感神经介导的血管收缩

• 批准号: 6700007
• 负责人: PAUL J FADEL
• 金额: $ 1.59万
• 依托单位: UT SOUTHWESTERN MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-02-01 至 2004-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6700007
• 关键词: age difference; atherosclerosis; cardiovascular disorder risk; clinical research; estrogen receptors; estrogens; female; hormone regulation /control mechanism; human middle age (35-64); human subject; inhibitor /antagonist; laboratory rat; nitric oxide synthase; oxygen transport; postdoctoral investigator; postmenopause; questionnaires; striated muscles; sympathetic nervous system; vasoconstriction; women' s health; young adult human (21-34)

DESCRIPTION (provided by applicant): Women are less susceptible than men to cardiovascular disease until they reach menopause, when cessation of ovarian hormone production is accompanied by an accelerated risk for atherosclerosis, coronary artery disease, and vascular dysfunction. Although several mechanisms by which estrogen may confer vascular protection have been proposed it remains unclear as to how estrogen exerts its beneficial effects on the vasculature. The main goal of this proposal is to examine the influence of estrogen on the regulation of sympathetic vasoconstriction in contracting skeletal muscle. To accomplish this goal complementary experiments will be performed in conscious humans and anesthetized rats. In pre and post-menopausal women changes in forearm muscle oxygenation and muscle sympathetic nerve activity will be measured during lower body negative pressure (LBNP) at rest and the responses will be compared to LBNP performed during rhythmic handgrip exercise. Studies will be performed when estrogen levels are high and again when estrogen concentrations are reduced to determine the impact of estrogen on sympathetically mediated vasoconstriction. In rats, the effect of lumbar sympathetic nerve stimulation on femoral blood flow and hind limb muscle oxygenation will be examined in resting and contracting hind limb of ovariectomized and sham rats. Further studies will examine influences of estrogen levels on neuronal nitric oxide synthase expression in skeletal muscle to determine its possible role in mediating a beneficial effect of estrogen on peripheral hemodynamics during muscle contraction.

描述（由申请人提供）：女性比男性不易 心血管疾病直到更年期，止血 激素产生伴随着动脉粥样硬化的加速风险， 冠状动脉疾病和血管功能障碍。虽然有几种机制 提出雌激素可以赋予血管保护的雌激素仍然存在 尚不清楚雌激素如何对脉管系统产生有益作用。 该提案的主要目的是检查雌激素对 在收缩骨骼肌中的交感神经血管收缩调节。到 实现此目标互补实验将在有意识中进行 人类和麻醉大鼠。在绝经后和绝经后妇女中的变化 前臂肌肉氧合和肌肉交感神经活动将是 在静止下的下半身负压（LBNP）和反应时测量 将与有节奏的手绘运动过程中进行的LBNP进行比较。研究 当雌激素水平高时，将执行雌激素时 浓度降低以确定雌激素对 交感神经介导的血管收缩。在大鼠中，腰部的作用 股骨血流和后肢肌肉上的交感神经刺激 将在休息和收缩的后肢中检查氧合 卵巢切除和假大鼠。进一步的研究将研究 骨骼肌中神经元一氧化氮合酶表达上的雌激素水平 确定其在介导雌激素的有益作用中的可能作用 肌肉收缩期间的外周血流动力学。