Transmural Pressure During Cardiogenic Oscillations in Rodent Diaphragmatic Lymphatic Vessels

Negrini, Daniela; Moriondo, Andrea; Mukenge, Sylvain

doi:10.1089/lrb.2004.2.69

Cited by 50 publications

(72 citation statements)

References 30 publications

(64 reference statements)

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“…Smooth muscle cells were not observed in the smallest lymphatic vessel wall and, at variance with the arrangement of the lymphatic system in most organs (22), were only rarely found in the largest central collectors. This finding is in line with the extremely rare observation of spontaneous pressure waves during recording of intraluminar lymphatic pressure from diaphragmatic lymphatic vessels in rabbits and rats (13,17).…”

Section: Discussionsupporting

confidence: 88%

“…Hence, fluid entry is supported by a passive hydraulic pressure gradient developing between the pleural and/or peritoneal cavities and the lumen of the submesothelial lacunae. Direct measurements performed on rabbits and rats (13,17) have demonstrated that the hydraulic pressure in lymphatic diaphragmatic vessels (P lymph ), likely corresponding to the pleural Fig. 5.…”

Section: Discussionmentioning

confidence: 99%

“…In fact, because of obvious experimental difficulties, diaphragmatic P lymph has never been measured during spontaneous breathing. In the micropuncture experiments so far performed on the diaphragmatic lymphatics, the animals were paralyzed, and the chest was necessarily open to allow pipette insertion into the lymphatic vessels or adjacent interstitial space (13,17); in these conditions the recorded diaphragmatic P lymph values reflected the mechanical stress of the diaphragmatic tissue and its cardiogenic motion (17) but not the respiratory activity. Because of the anatomical arrangement of the diaphragm, it is quite difficult to infer what the diaphragmatic P lymph behavior might be during spontaneous breathing.…”

Section: Discussionmentioning

confidence: 99%

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Functional arrangement of rat diaphragmatic initial lymphatic network

Grimaldi¹,

Moriondo²,

Sciacca³

et al. 2006

American Journal of Physiology-Heart and Circulatory Physiology

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Fluid and solute flux between the pleural and peritoneal cavities, although never documented under physiological conditions, might play a relevant role in pathological conditions associated with the development of ascitis and pleural effusion and/or in the processes of tumor dissemination. To verify whether a pleuroperitoneal flux might take place through the diaphragmatic lymphatic network, the transdiaphragmatic pressure gradient (⌬P TD) was measured in five spontaneously breathing anesthetized rats. ⌬PTD was Ϫ1.93 cmH2O (SD 0.59) and Ϫ3.1 cmH2O (SD 0.82) at end expiration and at end inspiration, respectively, indicating the existence of a pressure gradient directed from the abdominal to the pleural cavity. Morphometrical analysis of the diaphragmatic lymphatic network was performed in the excised diaphragm of three additional rats euthanized with an anesthesia overdose. Optical and electron microscopy revealed that lymphatic submesothelial lacunae and lymphatic capillaries among the skeletal muscles fibers show the ultrastructural features of the socalled initial lymphatic vessels, namely, a discontinuous basal lamina and anchoring filaments linking the outer surface of the endothelial cells to connective tissue or to muscle fibers. Primary unidirectional valves in the wall of the initial lymphatics allow entrance of serosal fluid into the lymphatic network preventing fluid backflow, while unidirectional intraluminar valves in the transverse vessels convey lymph centripetally toward central collecting ducts. The complexity and anatomical arrangement of the two valves system suggests that, despite the existence of a favorable ⌬P TD, in the physiological condition no fluid bulk flow takes place between the pleural and peritoneal cavity through the diaphragmatic lymphatic network. intraluminar lymphatic pressure; serosal fluid pressure; tissue fluid homeostasis THE DRAINAGE OF FLUID, solutes of large molecular weight, and even cells from the pleural and the peritoneal cavity mainly occurs through the lymphatic system located in the parietal mesothelial and submesothelial tissues covering the thoracic and abdominal walls and both surfaces of the diaphragm (10,12,15,19). The ability of the diaphragmatic lymphatic system to drain fluid from both the pleural and peritoneal cavity has been assessed in normal healthy animals (10, 12) by using experimental approaches that were meant to respect the physiological condition as much as possible. The results from these studies, whereas demonstrating the importance of the diaphragmatic lymphatics in maintaining the serosal fluid volume, failed to reveal or suggest the occurrence of fluid transfer between the pleural and peritoneal cavities through the diaphragm itself. However, the existence of direct transdiaphragmatic lymphatic pathways often has been proposed (4, 25) to explain clinical observations like the development of hydrothoraces secondary to peritoneal dialysis or ascitis. At present it is not clear whether the recruitment of a direct transdiaphragmatic pathway wi...

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Section: Discussionsupporting

confidence: 88%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Functional arrangement of rat diaphragmatic initial lymphatic network

Grimaldi¹,

Moriondo²,

Sciacca³

et al. 2006

American Journal of Physiology-Heart and Circulatory Physiology

Self Cite

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show abstract

“…Both spontaneous active (intrinsic) lymphangion contractions and passive (extrinsic) tissue compressive forces cooperate to generate sufficient pressure gradients to propel lymph centrally. [73][74][75][76] To maintain a unidirectional lymph flow, lymphatics can propel lymph by spontaneous phasic contractions as a result of coordinated contractility of the LMC in the wall of collecting lymphatics. 77 Rat and guinea pig studies have shown that the spontaneous phasic contractions of lymphatics are initiated by a pacemaker electrical activity located in each segment near the valves, with the contraction cycles of lymphatics divided into a contraction phase (systolic) and a relaxation phase (diastolic).…”

Section: General Functions Of the Lymphatic Systemmentioning

confidence: 99%

Anatomy and roles of lymphatics in inflammatory diseases

Al‐Kofahi

Yun

Minagar

et al. 2017

Clinical & Exp Neuroim

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The lymphatic system maintains tissue homeostasis by transporting interstitial fluid, lipids and debris from tissues to the main circulation, and delivers antigen and antigen presenting cells to local lymph nodes where they elicit immune responses. During inflammation, lymph flow increases to limit edema and prevents tissue antigen-presenting cell transport. Lymphatics also adjust their contractile activity to increase fluid transfer during acute inflammation. Conversely, chronic inflammation can provoke lymphostasis, which might limit pathogen spread within the circulation; however, decreased lymph flow leads to the persistence of immune cells and mediators in tissues to intensifying injury. Here, we review lymphatic structure function within the gut, heart and central nervous system, discussing potential roles of these lymphatics in the etiology of inflammatory bowel disease, myocarditis and neurovascular disease, and as novel targets for therapeutic management of several disease states.

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“…Subsequent lymph propulsion relies on the presence of hydraulic pressure gradients developing between two consecutive tracts of the lymphatic vessel, separated by unidirectional intraluminal valves. It has been shown that the pressure gradients necessary for both formation and propulsion of diaphragmatic lymph may result from forces arising in the tissue and transmitted to the vessel lumen during the cardiac (30) and/or respiratory cycle (22). In addition, unlike what was observed in linear vessels of the central tendineous diaphragm, several loops and short linear tracts located at the outer diaphragm muscular periphery display an intrinsic pumping activity.…”

Section: In Diaphragmatic Lymphatics Flow Velocity and Lymph Flow Wementioning

confidence: 99%

Lymph flow pattern in pleural diaphragmatic lymphatics during intrinsic and extrinsic isotonic contraction

Moriondo

Solari

Marcozzi

et al. 2016

American Journal of Physiology-Heart and Circulatory Physiology

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Moriondo A, Solari E, Marcozzi C, Negrini D. Lymph flow pattern in pleural diaphragmatic lymphatics during intrinsic and extrinsic isotonic contraction. Am J Physiol Heart Circ Physiol 310: H60 -H70, 2016. First published October 29, 2015 doi:10.1152/ajpheart.00640.2015.-Peripheral rat diaphragmatic lymphatic vessels, endowed with intrinsic spontaneous contractility, were in vivo filled with fluorescent dextrans and microspheres and subsequently studied ex vivo in excised diaphragmatic samples. Changes in diameter and lymph velocity were detected, in a vessel segment, during spontaneous lymphatic smooth muscle contraction and upon activation, through electrical whole-field stimulation, of diaphragmatic skeletal muscle fibers. During intrinsic contraction lymph flowed both forward and backward, with a net forward propulsion of 14.1 Ϯ 2.9 m at an average net forward speed of 18.0 Ϯ 3.6 m/s. Each skeletal muscle contraction sustained a net forward-lymph displacement of 441.9 Ϯ 159.2 m at an average velocity of 339.9 Ϯ 122.7 m/s, values significantly higher than those documented during spontaneous contraction. The flow velocity profile was parabolic during both spontaneous and skeletal muscle contraction, and the shear stress calculated at the vessel wall at the highest instantaneous velocity never exceeded 0.25 dyne/cm 2 . Therefore, we propose that the synchronous contraction of diaphragmatic skeletal muscle fibers recruited at every inspiratory act dramatically enhances diaphragmatic lymph propulsion, whereas the spontaneous lymphatic contractility might, at least in the diaphragm, be essential in organizing the pattern of flow redistribution within the diaphragmatic lymphatic circuit. Moreover, the very low shear stress values observed in diaphragmatic lymphatics suggest that, in contrast with other contractile lymphatic networks, a likely interplay between intrinsic and extrinsic mechanisms be based on a mechanical and/or electrical connection rather than on nitric oxide release. lymph propulsion; tissue stress; spontaneous lymphatic contractility NEW AND NOTEWORTHYIn diaphragmatic lymphatics, flow velocity and lymph flow were more than two order of magnitude greater during contraction of diaphragmatic skeletal muscle than during spontaneous contraction of lymphatic smooth muscles, suggesting a marginal role of the latter in setting lymph flow in rhythmically moving, thoracic tissues.THE PLEURAL DIAPHRAGMATIC lymphatic system is composed of linear lymphatic vessels preferentially located in the tendineous and the medial muscular portion of the diaphragm, and of a more complex net of loop-like structures interconnected by short linear tracts and preferentially located at the most peripheral diaphragmatic rim (18). Given the strategic role played by pleural lymphatics in setting the correct pleural fluid volume and subatmospheric pressure required to maintain the normal lung chest wall coupling (29), much effort has been spent in the study of the inner regulatory mechanisms of lymph drainage and propulsion in th...

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Transmural Pressure During Cardiogenic Oscillations in Rodent Diaphragmatic Lymphatic Vessels

Abstract: The data revealed a great functional complexity of the diaphragmatic lymphatic network and suggested that cardiogenic oscillations may play an important role in promoting lymph formation and propulsion from interstitial tissues with subatmospheric tissue pressure.

Cited by 50 publications

References 30 publications

Functional arrangement of rat diaphragmatic initial lymphatic network

Functional arrangement of rat diaphragmatic initial lymphatic network

Anatomy and roles of lymphatics in inflammatory diseases

Lymph flow pattern in pleural diaphragmatic lymphatics during intrinsic and extrinsic isotonic contraction

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