UBC-Nepal expedition: upper and lower limb conduit artery shear stress and flow-mediated dilation on ascent to 5,050 m in lowlanders and Sherpa

American Journal of Physiology. Heart and Circulatory Physiology
Joshua C TremblayPhilip N Ainslie

Abstract

The study of conduit artery endothelial adaptation to hypoxia has been restricted to the brachial artery, and comparisons with highlanders have been confounded by differences in altitude exposure, exercise, and unknown levels of blood viscosity. To address these gaps, we tested the hypothesis that lowlanders, but not Sherpa, would demonstrate decreased mean shear stress and increased retrograde shear stress and subsequently reduced flow-mediated dilation (FMD) in the upper and lower limb conduit arteries on ascent to 5,050 m. Healthy lowlanders (means ± SD, n = 22, 28 ± 6 yr) and Sherpa ( n = 12, 34 ± 11 yr) ascended over 10 days, with measurements taken on nontrekking days at 1,400 m (baseline), 3,440 m ( day 4), 4,371 m ( day 7), and 5,050 m ( day 10). Arterial blood gases, blood viscosity, shear stress, and FMD [duplex ultrasound of the brachial and superficial femoral arteries (BA and SFA, respectively)] were acquired at each time point. Ascent decreased mean and increased retrograde shear stress in the upper and lower limb of lowlanders and Sherpa. Although BA FMD decreased in lowlanders from 7.1 ± 3.9% to 3.8 ± 2.8% at 5,050 versus 1,400 m ( P < 0.001), SFA FMD was preserved. In Sherpa, neither BA nor SFA FMD were changed...Continue Reading

References

Sep 13, 1969·Nature·C G CaroR C Schroter
Jul 18, 2001·Journal of Applied Physiology·R J WoodmanD Green
Nov 24, 2001·Nature·C M BeallS C Erzurum
Feb 4, 2003·The Journal of Physiology·Jim Hansen, Mikael Sander
Jan 28, 2004·Journal of Magnetic Resonance Imaging : JMRI·Sheng Ping WuErik M Pedersen
Jul 14, 2004·Hypertension·Michael F O'Rourke, Wilmer W Nichols
Jul 14, 2004·Hypertension·Gary F MitchellEmelia J Benjamin
Jul 25, 2006·American Journal of Physiology. Heart and Circulatory Physiology·Beth A ParkerDavid N Proctor
Dec 16, 2006·Journal of Applied Physiology·Kyra E Pyke, Michael E Tschakovsky
May 15, 2007·Proceedings of the National Academy of Sciences of the United States of America·Cynthia M Beall
Jun 9, 2007·Journal of Applied Physiology·Steven K NishiyamaRussell S Richardson
Aug 29, 2007·Journal of Applied Physiology·Ryan A Harris, Jaume Padilla
Nov 1, 2007·Proceedings of the National Academy of Sciences of the United States of America·S C ErzurumC M Beall
Feb 5, 2008·American Journal of Physiology. Heart and Circulatory Physiology·S C NewcomerC A Ray
Aug 30, 2008·The Journal of Physiology·Toni M TinkenDaniel J Green
Sep 9, 2008·American Journal of Physiology. Heart and Circulatory Physiology·Dick H J ThijssenDaniel J Green
Apr 7, 2009·Medicine and Science in Sports and Exercise·Dick H J ThijssenDaniel J Green
Apr 22, 2009·Hypertension·Dick H J ThijssenDaniel J Green
Jun 26, 2009·European Journal of Applied Physiology·Katharine D CurrieJack M Goodman
Feb 16, 2010·American Journal of Physiology. Heart and Circulatory Physiology·Jaume PadillaPaul J Fadel
Mar 2, 2010·American Journal of Physiology. Heart and Circulatory Physiology·John R Halliwill, Christopher T Minson
Mar 27, 2010·The International Journal of Cardiovascular Imaging·Yoichi InabaSteven R Bergmann
Mar 31, 2010·Hypertension·Ryan A HarrisRussell S Richardson
Oct 19, 2010·American Journal of Physiology. Heart and Circulatory Physiology·Dick H J ThijssenDaniel J Green
Apr 23, 2011·Journal of Applied Physiology·Dick H J ThijssenDaniel J Green
Nov 18, 2011·The New England Journal of Medicine·Allison J JanochaSerpil C Erzurum
Feb 4, 2012·Free Radical Biology & Medicine·Cynthia M BeallSerpil C Erzurum
Feb 23, 2012·Scientific Reports·Denny Z LevettUNKNOWN Caudwell Extreme Everest Research Group
May 19, 2012·Medicine and Science in Sports and Exercise·Erika IwamotoKoji Ishida
Oct 9, 2012·International Journal of Cardiology·Rouyanne T RasPeter L Zock
Dec 25, 2012·Atherosclerosis·Greg Atkinson, Alan M Batterham

❮ Previous
Next ❯

Citations

May 28, 2019·Experimental Physiology·Ryan S GartenAndrew Mcintyre
Nov 5, 2019·The Journal of Physiology·Michael M TymkoPhilip N Ainslie
Sep 5, 2020·American Journal of Physiology. Heart and Circulatory Physiology·Joshua C TremblayChristoph Siebenmann
May 24, 2020·The Journal of Physiology·Emeric StaufferSamuel Verges
Aug 24, 2019·American Journal of Physiology. Heart and Circulatory Physiology·Joshua C TremblayKyra E Pyke
Sep 27, 2019·Frontiers in Physiology·Sushil Bhandari, Gianpiero L Cavalleri

❮ Previous
Next ❯

Software Mentioned

STAT
Sherpa

Related Concepts

Trending Feeds

COVID-19

Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Blastomycosis

Blastomycosis fungal infections spread through inhaling Blastomyces dermatitidis spores. Discover the latest research on blastomycosis fungal infections here.

Nuclear Pore Complex in ALS/FTD

Alterations in nucleocytoplasmic transport, controlled by the nuclear pore complex, may be involved in the pathomechanism underlying multiple neurodegenerative diseases including Amyotrophic Lateral Sclerosis and Frontotemporal Dementia. Here is the latest research on the nuclear pore complex in ALS and FTD.

Applications of Molecular Barcoding

The concept of molecular barcoding is that each original DNA or RNA molecule is attached to a unique sequence barcode. Sequence reads having different barcodes represent different original molecules, while sequence reads having the same barcode are results of PCR duplication from one original molecule. Discover the latest research on molecular barcoding here.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Evolution of Pluripotency

Pluripotency refers to the ability of a cell to develop into three primary germ cell layers of the embryo. This feed focuses on the mechanisms that underlie the evolution of pluripotency. Here is the latest research.

Position Effect Variegation

Position Effect Variagation occurs when a gene is inactivated due to its positioning near heterochromatic regions within a chromosome. Discover the latest research on Position Effect Variagation here.

STING Receptor Agonists

Stimulator of IFN genes (STING) are a group of transmembrane proteins that are involved in the induction of type I interferon that is important in the innate immune response. The stimulation of STING has been an active area of research in the treatment of cancer and infectious diseases. Here is the latest research on STING receptor agonists.

Microbicide

Microbicides are products that can be applied to vaginal or rectal mucosal surfaces with the goal of preventing, or at least significantly reducing, the transmission of sexually transmitted infections. Here is the latest research on microbicides.