健康男性的衰老和前臂后结合性α-上腺体血管收缩
Frank A Dinenno1, Niki M Dietz, Michael J Joyner
1Department of Anesthesiology and General Clinical Research Center, Mayo Clinic and Foundation, Rochester, Minn 55905, USA.
Circulation
|September 11, 2002
概括
衰老会降低血管对诺亚上腺素的反应,特别是在α1-上腺素受体. 这种与年龄相关的血管反应能力下降有助于降低健康男性的交感血管收缩.
科学领域:
- 心血管生理学心血管生理学
- 衰老研究研究 衰老研究
- 神经内分泌学神经内分泌学
背景情况:
- 肌肉交感神经活动随着人类的年龄增长而增加.
- 然而,这并没有导致前臂血管收缩的增加.
- 这表明后结合性α-上腺素反应的潜在减少.
研究的目的:
- 为了测试是否降低对诺拉上腺素 (NE) 的α-上腺素反应导致随着年龄的增长而变的血管收缩.
- 要确定这种效应是否特异于α1-或α2-上腺素受体.
主要方法:
- 在年轻和年长的男性中,比较前臂血流 (FBF) 对氨酸,氨酸 (α1-agonist) 和克洛尼丁 (α2-agonist) 的反应.
- 测量了深静脉诺亚上腺素 (NE) 度.
- 使用局部β-上腺素阻断和非选择性α-阻断.
主要成果:
- 提拉胺诱导的FBF减少在老年男性中减弱,尽管NE释放量较高.
- 烯诱导的FBF减少也在老年男性中减弱,表明阿尔法1-上腺素反应能力降低.
- 克洛尼丁的反应在不同年龄组之间是相似的,这表明α2受体不受影响.
- 在老年男性中,整体的同情性α-上腺体血管收缩体度较低.
结论:
- 人类的衰老降低了前臂后连接性阿尔法上腺素对内源性NE的反应.
- 这种减少似乎特异于α1-上腺素受体.
- 交感性α-上腺体血管收缩对基底前臂血管度的贡献在健康的老年男性中减少.
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