PMID- 32401629
OWN - NLM
STAT- MEDLINE
DCOM- 20201005
LR  - 20240402
IS  - 1522-1490 (Electronic)
IS  - 0363-6119 (Print)
IS  - 0363-6119 (Linking)
VI  - 319
IP  - 1
DP  - 2020 Jul 1
TI  - Healthy active older adults have enhanced K(+) channel-dependent endothelial 
      vasodilatory mechanisms.
PG  - R19-R25
LID - 10.1152/ajpregu.00049.2020 [doi]
AB  - Microvascular endothelial dysfunction, a precursor to atherosclerotic 
      cardiovascular disease, increases with aging. Endothelium-derived hyperpolarizing 
      factors (EDHFs), which act through K(+) channels, regulate blood flow and are 
      important to vascular health. It is unclear how EDHFs change with healthy aging. 
      To evaluate microvascular endothelial reliance on K(+) channel-mediated dilation 
      as a function of age in healthy humans. Microvascular function was assessed using 
      intradermal microdialysis in healthy younger (Y; n = 7; 3 M/4 W; 26 +/- 1 yr) and 
      older adults (O; n = 12; 5 M/7 W; 64 +/- 2 yr) matched for V̇o(2peak) (Y: 
      39.0 +/- 3.8, O: 37.6 +/- 3.1 mL.kg(-1).min(-1)). Participants underwent graded local 
      infusions of: the K(+) channel activator Na(2)S (10(-6) to 10(-1) M), 
      acetylcholine (ACh, 10(-10) to 10(-1) M), ACh + the K(+) channel inhibitor 
      tetraethylammonium (TEA; 25 or 50 mM), and ACh + the nitric oxide 
      synthase-inhibitor l-NAME (15 mM). Red blood cell flux was measured with 
      laser-Doppler flowmetry and used to calculate cutaneous vascular conductance 
      (CVC; flux/mean arterial pressure) as a percentage of each site-specific maximum 
      (%CVC(max), 43 degrees C+28 mM sodium nitroprusside). The %CVC(max) response to Na(2)S 
      was higher in older adults (mean, O: 51.7 +/- 3.9% vs. Y: 36.1 +/- 5.3%; P = 0.03). 
      %CVC(max) was lower in the ACh+TEA vs. the ACh site starting at 10(-5) M (ACh: 
      34.0 +/- 5.7% vs. ACh+TEA: 19.4 +/- 4.5%; P = 0.002) in older and at 10(-4) M (ACh: 
      54.5 +/- 9.4% vs. ACh+TEA: 31.2 +/- 6.7%; P = 0.0002) in younger adults. %CVC(max) 
      was lower in the ACh+l-NAME vs. the ACh site in both groups starting at 10(-4) M 
      ACh (Y: P < 0.001; O: P = 0.02). Healthy active older adults have enhanced K(+) 
      channel-dependent endothelial vasodilatory mechanisms, suggesting increased 
      responsiveness to EDHFs with age.
FAU - Serviente, Corinna
AU  - Serviente C
AD  - Department of Kinesiology, Pennsylvania State University, University Park, 
      Pennsylvania.
AD  - Center for Healthy Aging, Pennsylvania State University, University Park, 
      Pennsylvania.
FAU - Berry, Craig W
AU  - Berry CW
AD  - Department of Kinesiology, Pennsylvania State University, University Park, 
      Pennsylvania.
FAU - Kenney, W Larry
AU  - Kenney WL
AD  - Department of Kinesiology, Pennsylvania State University, University Park, 
      Pennsylvania.
AD  - Center for Healthy Aging, Pennsylvania State University, University Park, 
      Pennsylvania.
FAU - Alexander, Lacy M
AU  - Alexander LM
AD  - Department of Kinesiology, Pennsylvania State University, University Park, 
      Pennsylvania.
AD  - Center for Healthy Aging, Pennsylvania State University, University Park, 
      Pennsylvania.
LA  - eng
GR  - R01 AG067471/AG/NIA NIH HHS/United States
GR  - R01 AG007004/AG/NIA NIH HHS/United States
GR  - T32-AG049676/AG/NIA NIH HHS/United States
GR  - R01 HL093238/HL/NHLBI NIH HHS/United States
GR  - UL1 TR002014/TR/NCATS NIH HHS/United States
GR  - UL1-TR002014/TR/NCATS NIH HHS/United States
PT  - Journal Article
PT  - Research Support, N.I.H., Extramural
PT  - Research Support, Non-U.S. Gov't
DEP - 20200513
PL  - United States
TA  - Am J Physiol Regul Integr Comp Physiol
JT  - American journal of physiology. Regulatory, integrative and comparative 
      physiology
JID - 100901230
RN  - 0 (Biological Factors)
RN  - 0 (Enzyme Inhibitors)
RN  - 0 (Potassium Channel Blockers)
RN  - 0 (Potassium Channels)
RN  - 0 (endothelium-dependent hyperpolarization factor)
RN  - V55S2QJN2X (NG-Nitroarginine Methyl Ester)
SB  - IM
MH  - Adult
MH  - Aged
MH  - Aging/physiology
MH  - Anaerobic Threshold/physiology
MH  - Biological Factors/physiology
MH  - Endothelium, Vascular/*physiology
MH  - Enzyme Inhibitors/pharmacology
MH  - Erythrocytes/drug effects/physiology
MH  - Female
MH  - Healthy Aging/*physiology
MH  - Humans
MH  - Male
MH  - Microcirculation
MH  - Middle Aged
MH  - NG-Nitroarginine Methyl Ester/pharmacology
MH  - Potassium Channel Blockers/pharmacology
MH  - Potassium Channels/agonists/*physiology
MH  - Regional Blood Flow/physiology
MH  - Vasodilation/*physiology
PMC - PMC7468792
OTO - NOTNLM
OT  - aging
OT  - endothelium-derived hyperpolarizing factors
OT  - microvascular function
OT  - skin blood flow
OT  - vasodilation
COIS- No conflicts of interest, financial or otherwise, are declared by the authors.
EDAT- 2020/05/14 06:00
MHDA- 2020/10/06 06:00
PMCR- 2021/07/01
CRDT- 2020/05/14 06:00
PHST- 2020/05/14 06:00 [pubmed]
PHST- 2020/10/06 06:00 [medline]
PHST- 2020/05/14 06:00 [entrez]
PHST- 2021/07/01 00:00 [pmc-release]
AID - R-00049-2020 [pii]
AID - 10.1152/ajpregu.00049.2020 [doi]
PST - ppublish
SO  - Am J Physiol Regul Integr Comp Physiol. 2020 Jul 1;319(1):R19-R25. doi: 
      10.1152/ajpregu.00049.2020. Epub 2020 May 13.