Impairments in central cardiovascular function contribute to attenuated reflex vasodilation in aged skin.
Impairments in central cardiovascular function contribute to attenuated reflex vasodilation in aged skin.
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中枢心血管功能受损会导致老化皮肤的反射性血管舒张减弱。
DOI：
10.1152/japplphysiol.00729.2015
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
Kenney,WLarry
中科院分区：
文献类型：
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作者：
Greaney,JodyL;Stanhewicz,AnnaE;Proctor,DavidN;Alexander,LacyM;Kenney,WLarry
在仰卧被动加热过程中，老年人的皮肤血流量（SkBF）和心输出量（Qc）的增加都变钝。本文的目的是确定急性校正老年皮肤外周血管舒张能力对被动加热的综合心血管反应的影响。第二个目的是在存在（直立姿势）和不存在（动态运动）中心静脉压挑战的情况下检查高温期间的SkBF-Qcreation。我们假设SkBF的增加会伴随着Qc的增加。11名健康老年人（69 ± 3岁）在服用英替沙丙蝶呤（BH 4，一种一氧化氮合酶辅因子; 10 mg/kg）或安慰剂（随机双盲交叉设计）后接受仰卧被动加热（核心温度升高0.8°C;水灌注服）。12名年轻（24 ± 1岁）受试者作为对照组。测量仰卧位加热、加热+直立位加热和加热+动力性运动时的SkBF（激光多普勒血流仪）和Qc（开路乙炔洗入）。在整个仰卧和直立加热，sapropterin完全恢复的SkBF反应的老年人的年轻人，但Qcremained钝化。在热+直立姿势期间，未接受治疗的老年受试者的SkBF未能降低。在动态运动期间，SkBF-Qc没有年龄或治疗相关的差异。这项研究的主要发现是被动热应激的Qc反应的钝化与年龄直接相关，而不是老年皮肤的外周血管舒张能力的钝化。此外，老年人SkBF的外周损伤可能导致体温过高期间中心静脉压挑战时的不适当反应。
During supine passive heating, increases in skin blood flow (SkBF) and cardiac output (Qc) are both blunted in older adults. The aim here was to determine the effect of acutely correcting the peripheral vasodilatory capacity of aged skin on the integrated cardiovascular responses to passive heating. A secondary aim was to examine the SkBF-Qcrelation during hyperthermia in the presence (upright posture) and absence (dynamic exercise) of challenges to central venous pressure. We hypothesized that greater increases in SkBF would be accompanied by greater increases in Qc. Eleven healthy older adults (69 ± 3 yr) underwent supine passive heating (0.8°C rise in core temperature; water-perfused suit) after ingesting sapropterin (BH4, a nitric oxide synthase cofactor; 10 mg/kg) or placebo (randomized double-blind crossover design). Twelve young (24 ± 1 yr) subjects served as a comparison group. SkBF (laser-Doppler flowmetry) and Qc(open-circuit acetylene wash-in) were measured during supine heating, heating + upright posture, and heating + dynamic exercise. Throughout supine and upright heating, sapropterin fully restored the SkBF response of older adults to that of young adults but Qcremained blunted. During heat + upright posture, SkBF failed to decrease in untreated older subjects. There were no age- or treatment-related differences in SkBF-Qcduring dynamic exercise. The principal finding of this study was that the blunted Qcresponse to passive heat stress is directly related to age as opposed to the blunted peripheral vasodilatory capacity of aged skin. Furthermore, peripheral impairments to SkBF in the aged may contribute to inapposite responses during challenges to central venous pressure during hyperthermia.