Barium reduces resting blood flow and inhibits potassium-induced vasodilation in the human forearm

Circulation
Matthew DawesJ M Ritter

Abstract

Increasing extracellular K+ concentration within and just above the physiological range hyperpolarizes and relaxes vascular smooth muscle in vitro. These actions involve inwardly rectifying potassium channels (K(IR)) and Na+/K+ ATPase, which are inhibited, respectively, by Ba2+ and ouabain. The role (if any) of K(IR) in controlling human resistance vessel tone is unknown, and we investigated this in the forearm. Blood flow was measured by plethysmography in healthy men. Drugs and electrolytes were infused through the brachial artery. BaCl2 (4 micromol/min, also used in subsequent experiments) increased Ba2+ plasma concentration in the infused forearm to 50+/-0.8 micromol/L (mean+/-SEM) and reduced blood flow by 24+/-4% (n=8, P<0.001) without causing systemic effects. Ouabain (2.7 nmol/min), alone and with BaCl2, reduced flow by 10+/-2% and 28+/-3%, respectively (n=10). Incremental infusions of KCl (0.05, 0.1, and 0.2 mmol/min) increased flow from baseline by 1.0+/-0.2, 2.0+/-0.4, and 4.2+/-0.5 mL/min per deciliter forearm, respectively. Responses to KCl (0.2 mmol/min) were inhibited by BaCl2, alone and plus ouabain, by 60+/-9% and 88+/-6%, respectively (both P< or =0.01). In control experiments, norepinephrine (240 pmol/min) re...Continue Reading

References

Jan 11, 1975·IEEE Transactions on Bio-medical Engineering·D E HokansonD E Strandness
Feb 1, 1992·Journal of the American Society of Nephrology : JASN·S R SmithL P Svetkey
Oct 1, 1991·Annals of Emergency Medicine·C H Johnson, V J VanTassell
Sep 1, 1990·The American Journal of Physiology·J G McCarron, W Halpern
Oct 1, 1988·The Journal of Physiology·F R Edwards, G D Hirst
Apr 1, 1995·The American Journal of Physiology·M T Nelson, J M Quayle
Nov 14, 1997·Physiological Reviews·J M QuayleN B Standen
Mar 10, 1998·British Journal of Clinical Pharmacology·J R PetrieJ M Connell
Mar 6, 1999·The Journal of Physiology·K K BradleyB Horowitz
Feb 13, 2001·British Journal of Clinical Pharmacology·M J Caulfield
Jul 1, 1953·The Journal of Physiology·R J WHITNEY

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Citations

Apr 26, 2008·Pflügers Archiv : European journal of physiology·Won Sun ParkYung E Earm
Oct 16, 2002·Trends in Pharmacological Sciences·Rudi BusseArthur H Weston
Nov 16, 2010·American Journal of Physiology. Heart and Circulatory Physiology·Hiroto MiuraDavid D Gutterman
Oct 3, 2006·American Journal of Physiology. Heart and Circulatory Physiology·Jianhua LiLawrence I Sinoway
Aug 31, 2011·Cardiology Research and Practice·Muhiddin A Ozkor, Arshed A Quyyumi
Jul 11, 2012·The Journal of Physiology·Anne R CreceliusFrank A Dinenno
Aug 21, 2013·Seminars in Nephrology·Hector Castro, Leopoldo Raij
Mar 13, 2010·American Journal of Kidney Diseases : the Official Journal of the National Kidney Foundation·Eckhart BüssemakerHans Oberleithner
Feb 11, 2004·British Journal of Pharmacology·E E M van GinnekenG A Rongen
Aug 19, 2008·Fundamental & Clinical Pharmacology·Jeremy BellienRobinson Joannides
Dec 31, 2005·Muscle & Nerve·Mireille C P Van BeekveltMachiel J Zwarts
Jul 19, 2006·International Immunopharmacology·Tomoe FujitaMasataka Majima
Feb 7, 2015·British Journal of Clinical Pharmacology·L YangI B Wilkinson
Dec 3, 2014·Nutrition, Metabolism, and Cardiovascular Diseases : NMCD·N BlanchJ B Keogh
Jan 23, 2004·Journal of the American College of Cardiology·John E Macdonald, Allan D Struthers
Jun 16, 2016·The Journal of Physiology·Christopher M Hearon, Matthew L Racine
Mar 31, 2015·Physiology & Behavior·Ruth Gutierrez-AguilarYvonne M Ulrich-Lai
Dec 7, 2018·The Journal of Physiology·Christopher M HearonFrank A Dinenno
Feb 10, 2006·American Journal of Physiology. Regulatory, Integrative and Comparative Physiology·Francis J HaddyMichel Feletou
May 7, 2013·American Journal of Physiology. Heart and Circulatory Physiology·Anne R CreceliusFrank A Dinenno
Dec 3, 2005·Journal of Applied Physiology·Jianhua LiYuk-Chow Ng
Dec 12, 2020·American Journal of Physiology. Heart and Circulatory Physiology·Joel D TrinityRussell S Richardson

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