Estrogen supplementation decreases norepinephrine-induced vasoconstriction and total body norepinephrine spillover in perimenopausal women
Estrogen supplementation decreases norepinephrine-induced vasoconstriction and total body norepinephrine spillover in perimenopausal women
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DOI：
10.1161/01.hyp.30.6.1538
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发表时间：
1997-12-01
期刊：
影响因子：
8.3
通讯作者：
Komesaroff, PA
中科院分区：
文献类型：
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作者：
Sudhir, K;Esler, MD;Komesaroff, PA
据报道，雌激素可预防女性心血管疾病的发生，但其作用机制尚不明确。我们假设雌激素可能会降低神经心血管张力。因此，我们研究了12名围绝经期妇女对外源性去甲肾上腺素和去甲肾上腺素溢出的反应，随机分为8周雌激素补充组（戊酸雌二醇，每日2毫克，n=7）或安慰剂组（n=5）。前臂血流量通过静脉闭塞容积描记术测量，血管活性药物通过肱动脉插管输注，剂量不影响血压或心率。用放射性示踪法测量全身和前臂去甲肾上腺素溢出量。前臂血管收缩剂对去甲肾上腺素（25、50和100 ng/min）的反应在补充雌激素后减弱（P= 0.002）。对血管紧张素II（8、16和32 ng/min）的血管收缩反应在雌激素后没有变化。补充雌激素后，去甲肾上腺素的总外溢量显著减少(雌激素前，700+/-152；雌激素后，439+/-150 ng/min； P
Estrogens are reported to provide protection against the development of cardiovascular disease in women, but the mechanisms underlying these effects are not well defined. We hypothesized that estrogen might reduce neural cardiovascular tone. We therefore studied responses to exogenous norepinephrine and norepinephrine spillover in 12 perimenopausal women randomized to 8 weeks of estrogen supplementation (estradiol valerate, 2 mg daily, n=7) or placebo (n=5). Forearm blood flow was measured by venous occlusion plethysmography, and vasoactive agents were infused through a brachial artery cannula in doses that did not influence blood pressure or heart rate. Total body and forearm norepinephrine spillover were measured by radiotracer methodology. Forearm vasoconstrictor responses to norepinephrine (25, 50, and 100 ng/min) were attenuated after estrogen supplementation (P=.002). Vasoconstrictor responses to angiotensin II (8, 16, and 32 ng/min) were unchanged postestrogen. There was a significant reduction in total body spillover of norepinephrine after estrogen supplementation (pre-estrogen, 700+/-152; postestrogen, 439+/-150 ng/min; P