HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 287/2/H735    most recent 00959.2003v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (8) Citing Articles via Google Scholar Google Scholar Articles by Momen, A. Articles by Sinoway, L. I. Search for Related Content PubMed PubMed Citation Articles by Momen, A. Articles by Sinoway, L. I.

Effect of aging on renal blood flow velocity during static exercise

¹Division of Cardiology, Pennsylvania State University College of Medicine, Milton S. Hershey Medical Center, Hershey 17033; and ²Lebanon Department of Veterans Affairs Medical Center, Lebanon, Pennsylvania 17042

Submitted 9 October 2003 ; accepted in final form 6 March 2004

During exercise, activation of the sympathetic nervous system causes reflex renal vasoconstriction. The effects of aging on this reflex are poorly understood. This study evaluated the effects of age on renal vasoconstrictor responses to handgrip. Seven older (65 ± 9 yr) and nine younger (25 ± 2 yr) subjects were studied. Beat-by-beat analyses of changes in renal blood flow velocity (RBV; duplex ultrasound) were performed during two handgrip paradigms. Arterial blood pressure (BP) and heart rate were also measured, and an index of renal vascular resistance (RVR) was calculated (BP/RBV). In protocol 1, fatiguing handgrip [40% of maximal voluntary contraction (MVC)] caused a greater increase in RVR in the older subjects (old 90% ± 15 increase, young 52% ± 4 increase; P = 0.03). During posthandgrip circulatory arrest (isolates muscle metaboreflex), the increases in RVR were only 1/2 of the increase seen at end grip. In protocol 2, 15-s bouts of handgrip at graded intensities led to increases in RVR in both subject groups. This effect was not seen until 50% MVC workload (P < 0.05). RVR responses occurred early and were greater in older than in younger subjects at 50% MVC (32 ± 6% vs. 16 ± 5%; P = 0.02) and 70% MVC (39 ± 11% vs. 24 ± 8%; P = 0.02). Static exercise-induced renal vasoconstriction is enhanced with aging. Because the characteristics of this response suggest a predominant role for mechanoreceptor engagement, we hypothesize that mechanoreceptor responses are augmented with aging.

kidney; sympathetic nervous system

This article has been cited by other articles:

				N. T. Kuipers, C. L. Sauder, M. L. Kearney, and C. A. Ray Interactive effect of aging and local muscle heating on renal vasoconstriction during isometric handgrip Am J Physiol Renal Physiol, August 1, 2009; 297(2): F327 - F332. [Abstract] [Full Text] [PDF]

				M. Y. Endo, R. Suzuki, N. Nagahata, N. Hayashi, A. Miura, S. Koga, and Y. Fukuba Differential arterial blood flow response of splanchnic and renal organs during low-intensity cycling exercise in women Am J Physiol Heart Circ Physiol, May 1, 2008; 294(5): H2322 - H2326. [Abstract] [Full Text] [PDF]

				J. M. Stewart, L. D. Montgomery, J. L. Glover, and M. S. Medow Changes in regional blood volume and blood flow during static handgrip Am J Physiol Heart Circ Physiol, January 1, 2007; 292(1): H215 - H223. [Abstract] [Full Text] [PDF]

				A. Momen, D. Bower, U. A. Leuenberger, J. Boehmer, S. Lerner, E. J. Alfrey, B. Handly, and L. I. Sinoway Renal vascular response to static handgrip exercise: sympathetic vs. autoregulatory control Am J Physiol Heart Circ Physiol, October 1, 2005; 289(4): H1770 - H1776. [Abstract] [Full Text] [PDF]

				A. Momen, D. Bower, J. Boehmer, A. R. Kunselman, U. A. Leuenberger, and L. I. Sinoway Renal blood flow in heart failure patients during exercise Am J Physiol Heart Circ Physiol, December 1, 2004; 287(6): H2834 - H2839. [Abstract] [Full Text] [PDF]