The role of -adrenergic receptors in mediating beat-by-beat sympathetic vascular transduction in the forearm of resting man

被引:82
|
作者
Fairfax, Seth T. [1 ]
Holwerda, Seth W. [1 ]
Credeur, Daniel P. [1 ]
Zuidema, Mozow Y. [1 ]
Medley, John H. [1 ]
Dyke, Peter C., II [1 ]
Wray, D. Walter [3 ]
Davis, Michael J. [1 ,2 ]
Fadel, Paul J. [1 ,2 ]
机构
[1] Univ Missouri, Columbia, MO 65212 USA
[2] Univ Missouri, Dalton Cardiovasc Res Ctr, Columbia, MO 65212 USA
[3] Univ Utah, Salt Lake City, UT USA
来源
JOURNAL OF PHYSIOLOGY-LONDON | 2013年 / 591卷 / 14期
关键词
NERVE ACTIVITY; NORADRENALINE RELEASE; ALPHA-ADRENOCEPTORS; ARTERY RETROGRADE; BLOOD-PRESSURE; SHEAR RATE; MUSCLE; VASOCONSTRICTION; RESPONSES; TONE;
D O I
10.1113/jphysiol.2013.250894
中图分类号
Q189 [神经科学];
学科分类号
071006 ;
摘要
Sympathetic vascular transduction is commonly understood to act as a basic relay mechanism, but under basal conditions, competing dilatory signals may interact with and alter the ability of sympathetic activity to decrease vascular conductance. Thus, we determined the extent to which spontaneous bursts of muscle sympathetic nerve activity (MSNA) mediate decreases in forearm vascular conductance (FVC) and the contribution of local -adrenergic receptor-mediated pathways to the observed FVC responses. In 19 young men, MSNA (microneurography), arterial blood pressure and brachial artery blood flow (duplex Doppler ultrasound) were continuously measured during supine rest. These measures were also recorded in seven men during intra-arterial infusions of normal saline, phentolamine (PHEN) and PHEN with angiotensin II (PHEN+ANG). The latter was used to control for increases in resting blood flow with -adrenergic blockade. Spike-triggered averaging was used to characterize beat-by-beat changes in FVC for 15 cardiac cycles following each MSNA burst and a peak response was calculated. Following MSNA bursts, FVC initially increased by +3.3 +/- 0.3% (P= 0.016) and then robustly decreased to a nadir of -5.8 +/- 1.6% (P < 0.001). The magnitude of vasoconstriction appeared graded with the number of consecutive MSNA bursts; while individual burst size only had a mild influence. Neither PHEN nor PHEN+ANG infusions affected the initial rise in FVC, but both infusions significantly attenuated the subsequent decrease in FVC (-2.1 +/- 0.7% and -0.7 +/- 0.8%, respectively; P < 0.001 vs. normal saline). These findings indicate that spontaneous MSNA bursts evoke robust beat-by-beat decreases in FVC that are exclusively mediated via -adrenergic receptors.
引用
收藏
页码:3637 / 3649
页数:13
相关论文
共 6 条
  • [1] The role of α-adrenergic receptors in mediating beat-by-beat sympathetic vascular transduction in resting humans
    Fairfax, Seth T.
    Credeur, Daniel P.
    Holwerda, Seth W.
    Zuidema, Mozow Y.
    Medley, John H.
    Dyke, Peter C., II
    Wray, D. Walter
    [J]. FASEB JOURNAL, 2013, 27
  • [2] Assessing sympathetic vascular transduction in humans: Beat-to-beat considerations
    Fairfax, Seth T.
    Vianna, Lauro C.
    Davis, Michael J.
    Fadel, Paul J.
    [J]. FASEB JOURNAL, 2011, 25
  • [3] Alpha males: muscle sympathetic discharge on beat-to-beat forearm vascular conductance
    Millar, Philip J.
    O'Donnell, Emma
    [J]. JOURNAL OF PHYSIOLOGY-LONDON, 2013, 591 (18): : 4375 - 4376
  • [4] Effects of sodium depletion on the role of AT1- and α-adrenergic receptors in the regulation of forearm vascular tone in humans
    Baan, J
    Chang, PC
    Vermeij, P
    Pfaffendorf, M
    van Zwieten, PA
    [J]. JOURNAL OF HYPERTENSION, 1999, 17 (02) : 229 - 235
  • [5] Beta 3 adrenergic receptors and modulation of eNOS: A key role for Rac1 in adrenergic signal transduction pathways in the vascular endothelium
    Kou, Ruqin
    Michel, Thomas
    [J]. CIRCULATION, 2007, 116 (16) : 308 - 308
  • [6] SYMPATHETIC BAROREFLEX CONTROL OF VASCULAR-RESISTANCE IN COMFORTABLY WARM MAN - ANALYSES OF NEUROGENIC CONSTRICTOR RESPONSES IN THE RESTING FOREARM AND IN ITS SEPARATE SKELETAL-MUSCLE AND SKIN TISSUE COMPARTMENTS
    EDFELDT, H
    LUNDVALL, J
    [J]. ACTA PHYSIOLOGICA SCANDINAVICA, 1993, 147 (04): : 437 - 447