Estrogen and Sympathetically Mediated Vasoconstriction

雌激素和交感神经介导的血管收缩

• 批准号: 6622328
• 负责人: PAUL J FADEL
• 金额: $ 4.64万
• 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 2004-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6622328
• 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）：女性比男性更不容易受到