The lymphatic system has many roles in normal body function. It is a key component to body fluid and macromolecular homeostasis, lipid absorption, and lymphocyte circulation. To accomplish these tasks the lymphatic system must regulate lymph circulation. The lymphatics normally transport lymph and its components against pressure gradients. It does so through the involvement of active and passive lymphatic pumps and valved vessels. Many lymphatics have been shown to possess spontaneous cyclical vasomotor activity, which has been shown to be important to the generation of lymph flow. This active lymph pump can be analyzed in a fashion analogous to the cardiac cycle. Lymph pressure, rate of pressure change, diameter, rate of diameter change, contraction frequency, ejection fraction, stroke volume, flow, can be determined to analyze lymphatic contractile function. Many extrinsic factors are known to influence the active lymph pump, such as neurotransmitters, humoral factors, and inflammatory products. Influences intrinsic to the lymphatic vessel such as transmural pressure are also known to influence the active lymph pump. However the effect of another important intrinsic factor, flow is not clear. Lymph flow exhibits a complicated pattern during normal lymphatic function that shows great changes in magnitude and also transient changes in direction. If the lymphatic contractile activity is sensitive to shear, lymph flow is not only the main result of the lymph pumps but it may also be a feedback influence on these vessels. In spite of the potential importance of the effects of flow on lymphatic contractility, there are only a few reports of the influence of imposed flow on an active lymph pump. We have shown an inhibition of the amplitude and frequency of contractions induced by a controlled increase in imposed flow in isolated lymphatic vessels. Others have shown increases in the contraction frequency, reductions in lymphatic diameters and decreases in the amplitude of contractions in isolated rat iliac microlymphatics as a result of increases in flow. So, it is not clearly understood if and/or how changes in the magnitude of flow can modulate the contractility of different lymphatic vessels. Additionally the answers to several more questions concerning the influence of changes in flow conditions in lymphatics are also still unclear.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL070308-07
Application #
7595166
Study Section
Hypertension and Microcirculation Study Section (HM)
Program Officer
Goldman, Stephen
Project Start
2003-03-15
Project End
2011-03-31
Budget Start
2009-04-01
Budget End
2010-03-31
Support Year
7
Fiscal Year
2009
Total Cost
$328,875
Indirect Cost
Name
Texas A&M University
Department
Physiology
Type
Schools of Medicine
DUNS #
835607441
City
College Station
State
TX
Country
United States
Zip Code
77845
Jamalian, Samira; Jafarnejad, Mohammad; Zawieja, Scott D et al. (2017) Demonstration and Analysis of the Suction Effect for Pumping Lymph from Tissue Beds at Subatmospheric Pressure. Sci Rep 7:12080
Jafarnejad, M; Cromer, W E; Kaunas, R R et al. (2015) Measurement of shear stress-mediated intracellular calcium dynamics in human dermal lymphatic endothelial cells. Am J Physiol Heart Circ Physiol 308:H697-706
Jafarnejad, Mohammad; Woodruff, Matthew C; Zawieja, David C et al. (2015) Modeling Lymph Flow and Fluid Exchange with Blood Vessels in Lymph Nodes. Lymphat Res Biol 13:234-47
Cromer, Walter; Wang, Wei; Zawieja, Scott D et al. (2015) Colonic Insult Impairs Lymph Flow, Increases Cellular Content of the Lymph, Alters Local Lymphatic Microenvironment, and Leads to Sustained Inflammation in the Rat Ileum. Inflamm Bowel Dis 21:1553-63
Bohlen, Harold Glenn (2015) Nitric oxide and the cardiovascular system. Compr Physiol 5:808-23
Kuan, Emma L; Ivanov, Stoyan; Bridenbaugh, Eric A et al. (2015) Collecting lymphatic vessel permeability facilitates adipose tissue inflammation and distribution of antigen to lymph node-homing adipose tissue dendritic cells. J Immunol 194:5200-10
Cromer, Walter E; Zawieja, Scott D; Tharakan, Binu et al. (2014) The effects of inflammatory cytokines on lymphatic endothelial barrier function. Angiogenesis 17:395-406
Quick, Christopher M; Criscione, John C; Kotiya, Akhilesh et al. (2014) Functional adaptation of bovine mesenteric lymphatic vessels to mesenteric venous hypertension. Am J Physiol Regul Integr Comp Physiol 306:R901-7
Rahbar, Elaheh; Akl, Tony; Coté, Gerard L et al. (2014) Lymph transport in rat mesenteric lymphatics experiencing edemagenic stress. Microcirculation 21:359-67
Bridenbaugh, Eric A; Wang, Wei; Srimushnam, Maya et al. (2013) An immunological fingerprint differentiates muscular lymphatics from arteries and veins. Lymphat Res Biol 11:155-71

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