Angiotensin II in the elderly: Impact of angiotensin II type 1 receptor sensitivity on peripheral hemodynamics

D. Walter Wray, Steven K. Nishiyama, Ryan A. Harris, Russell S. Richardson

Research output: Contribution to journalArticle

25 Citations (Scopus)

Abstract

Exercise hyperemia is attenuated in the elderly, which may be attributed to local vasoregulatory pathways within the skeletal muscle vasculature. Therefore, we sought to determine whether healthy aging is associated with changes in angiotensin II (Ang II) receptor sensitivity through measurements of leg blood flow in resting and exercising skeletal muscle. In 12 (n=6 young, 24± 1 years; n=6 older, 68±3 years) healthy volunteers, we determined changes in leg blood flow (ultrasound Doppler) before and during intra-arterial infusion of Ang II (0.8 ng/mL of leg blood flow per minute). Heart rate, arterial blood pressure, common femoral artery diameter, and mean blood velocity were measured at rest and during knee-extensor exercise at 20% and 40% of the maximal work rate (WR max). At rest, Ang II infusion decreased leg blood flow to a greater extent in older ( - 61±8%) subjects compared with younger subjects ( - 31 ±5%). Compared with rest, Ang II-mediated vasoconstriction (leg blood flow) during exercise was diminished in both older and younger subjects at 20% (older: - 7±5%; younger: - 21±2%) and 40% WR max (older: - 5±4%; younger: - 9±3%). These data identify a clear age-related hypersensitivity to Ang II in the resting leg, which may contribute to the recognized decrement in leg blood flow in this cohort. However, the diminished vasoconstriction to Ang II during exercise suggests that the elevation in Ang II type 1 receptor sensitivity documented at rest does not contribute significantly to the blunted exercise hyperemia experienced with advancing age.

Original languageEnglish (US)
Pages (from-to)1611-1616
Number of pages6
JournalHypertension
Volume51
Issue number6
DOIs
StatePublished - Jun 1 2008

Fingerprint

Angiotensin Type 1 Receptor
Angiotensin II
Leg
Hemodynamics
Exercise
Hyperemia
Vasoconstriction
Skeletal Muscle
Doppler Ultrasonography
Intra Arterial Infusions
Angiotensin Receptors
Femoral Artery
Knee
Healthy Volunteers
Arterial Pressure
Hypersensitivity
Heart Rate

Keywords

  • Angiotensin receptors
  • Basic science
  • Blood flow regulation
  • Elderly
  • Exercise

ASJC Scopus subject areas

  • Internal Medicine

Cite this

Angiotensin II in the elderly : Impact of angiotensin II type 1 receptor sensitivity on peripheral hemodynamics. / Wray, D. Walter; Nishiyama, Steven K.; Harris, Ryan A.; Richardson, Russell S.

In: Hypertension, Vol. 51, No. 6, 01.06.2008, p. 1611-1616.

Research output: Contribution to journalArticle

Wray, D. Walter ; Nishiyama, Steven K. ; Harris, Ryan A. ; Richardson, Russell S. / Angiotensin II in the elderly : Impact of angiotensin II type 1 receptor sensitivity on peripheral hemodynamics. In: Hypertension. 2008 ; Vol. 51, No. 6. pp. 1611-1616.
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