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: 292/4/R1510    most recent 00258.2006v1 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 ISI 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 ISI Web of Science (4) Citing Articles via Google Scholar Google Scholar Articles by Quick, C. M. Articles by Stewart, R. H. Search for Related Content PubMed PubMed Citation Articles by Quick, C. M. Articles by Stewart, R. H.

NEUROHUMORAL CONTROL OF CARDIOVASCULAR FUNCTION

Intrinsic pump-conduit behavior of lymphangions

¹Michael E. DeBakey Institute, Texas A&M University, College Station; ²Cardiovascular Research Institute, Texas A&M University System, Health Science Center, College Station; ³Department of Physiology and Pharmacology and ⁴Department of Biomedical Engineering, Texas A&M University, College Station, Texas; ⁵Department of Medical Physiology, Texas A&M University System, Health Science Center, College Station, Texas

Submitted 14 April 2006 ; accepted in final form 20 November 2006

Lymphangions, segments of lymphatic vessels bounded by valves, have characteristics of both ventricles and arteries. They can act primarily like pumps when actively transporting lymph against a pressure gradient. They also can act as conduit vessels when passively transporting lymph down a pressure gradient. This duality has implications for clinical treatment of several types of edema, since the strategy to optimize lymph flow may depend on whether it is most beneficial for lymphangions to act as pumps or conduits. To address this duality, we employed a simple computational model of a contracting lymphangion, predicted the flows at both positive and negative axial pressure gradients, and validated the results with in vitro experiments on bovine mesenteric vessels. This model illustrates that contraction increases flow for normal axial pressure gradients. With edema, limb elevation, or external compression, however, the pressure gradient might reverse, and lymph may flow passively down a pressure gradient. In such cases, the valves may be forced open during the entire contraction cycle. The vessel thus acts as a conduit, and contraction has the effect of increasing resistance to passive flow, thus inhibiting flow rather than promoting it. This analysis may explain a possible physiological benefit of the observed flow-mediated inhibition of the lymphatic pump at high flow rates.

lymphangion; time-varying elastance; shear stress-induced dilation

This article has been cited by other articles:

				C. M. Quick, B. L. Ngo, A. M. Venugopal, and R. H. Stewart Lymphatic pump-conduit duality: contraction of postnodal lymphatic vessels inhibits passive flow Am J Physiol Heart Circ Physiol, March 1, 2009; 296(3): H662 - H668. [Abstract] [Full Text] [PDF]

				A. M. Venugopal, C. M. Quick, G. A. Laine, and R. H. Stewart Optimal postnodal lymphatic network structure that maximizes active propulsion of lymph Am J Physiol Heart Circ Physiol, February 1, 2009; 296(2): H303 - H309. [Abstract] [Full Text] [PDF]

				M. J. Davis, A. M. Davis, C. W. Ku, and A. A. Gashev Myogenic constriction and dilation of isolated lymphatic vessels Am J Physiol Heart Circ Physiol, February 1, 2009; 296(2): H293 - H302. [Abstract] [Full Text] [PDF]

				A. Moriondo, F. Bianchin, C. Marcozzi, and D. Negrini Kinetics of fluid flux in the rat diaphragmatic submesothelial lymphatic lacunae Am J Physiol Heart Circ Physiol, September 1, 2008; 295(3): H1182 - H1190. [Abstract] [Full Text] [PDF]

				M. J. Davis, M. M. Lane, A. M. Davis, D. Durtschi, D. C. Zawieja, M. Muthuchamy, and A. A. Gashev Modulation of lymphatic muscle contractility by the neuropeptide substance P Am J Physiol Heart Circ Physiol, August 1, 2008; 295(2): H587 - H597. [Abstract] [Full Text] [PDF]

				A. J. Macdonald, K. P. Arkill, G. R. Tabor, N. G. McHale, and C. P. Winlove Modeling flow in collecting lymphatic vessels: one-dimensional flow through a series of contractile elements Am J Physiol Heart Circ Physiol, July 1, 2008; 295(1): H305 - H313. [Abstract] [Full Text] [PDF]

				C. M. Quick, A. M. Venugopal, R. M. Dongaonkar, G. A. Laine, and R. H. Stewart First-order approximation for the pressure-flow relationship of spontaneously contracting lymphangions Am J Physiol Heart Circ Physiol, May 1, 2008; 294(5): H2144 - H2149. [Abstract] [Full Text] [PDF]

				A. M. Venugopal, R. H. Stewart, G. A. Laine, R. M. Dongaonkar, and C. M. Quick Lymphangion coordination minimally affects mean flow in lymphatic vessels Am J Physiol Heart Circ Physiol, August 1, 2007; 293(2): H1183 - H1189. [Abstract] [Full Text] [PDF]

				J. K. Meisner, R. H. Stewart, G. A. Laine, and C. M. Quick Lymphatic vessels transition to state of summation above a critical contraction frequency Am J Physiol Regulatory Integrative Comp Physiol, July 1, 2007; 293(1): R200 - R208. [Abstract] [Full Text] [PDF]