A5084004072- Lymphatic System and Diseases
- Sympathectomy and Hyperhidrosis Treatments
- Planarian Biology and Electrostimulation
- Circadian rhythm and melatonin
- Mast cells and histamine
- Cerebrospinal fluid and hydrocephalus
- Spaceflight effects on biology
- Neuroscience of respiration and sleep
- Genetic and Kidney Cyst Diseases
- Cystic Fibrosis Research Advances
- Lymphatic Disorders and Treatments
- Cardiovascular Health and Disease Prevention
- Neonatal Respiratory Health Research
- Sleep and Wakefulness Research
- Liver Disease Diagnosis and Treatment
- IL-33, ST2, and ILC Pathways
- Electromagnetic Fields and Biological Effects
- Thermoregulation and physiological responses
- Neurological disorders and treatments
- Pancreatitis Pathology and Treatment
- Systemic Sclerosis and Related Diseases
- Blood properties and coagulation
- Anesthesia and Neurotoxicity Research
- Skin and Cellular Biology Research
- Chronic Obstructive Pulmonary Disease (COPD) Research
Bryan College
2019-2022
Texas A&M University
2007-2022
Texas A&M Health Science Center
2008-2020
Temple College
2009-2019
Baylor Scott & White Health
2016
Texas A&M University System
2001-2015
MACOM (United States)
2008
Mitchell Institute
2006
There are only a few reports of the influence imposed flow on an active lymph pump under conditions controlled intraluminal pressure. Thus, mechanisms not clearly defined. Rat mesenteric lymphatics and thoracic ducts were isolated, cannulated pressurized. Input output pressures adjusted to impose various flows. Lymphatic systolic diastolic diameters measured used determine contraction frequency indices. Imposed inhibited in both duct. The duct appeared more sensitive than did lymphatics....
To measure lymphocyte velocity, lymphatic contraction, and shear stress in phasically contracting lymphatics situ.A high-speed video system was used to capture multiple contraction cycles rat mesenteric preparations. The images were analyzed determine fluid volume flow rate, wall stress, retrograde flow.Lymphocyte density flux varied from 326 35,500 cells/microL 206 2,030 cells/min, respectively. Lymphatics contracted phasically, with a mean diameter 91 +/- 9.0 microm amplitudes of 39%....
Lymphatics are necessary for the generation and regulation of lymph flow. use phasic contractions extrinsic compressions to generate flow; tonic alter resistance. Lymphatic muscle exhibits important differences from typical vascular smooth muscle. In this study, thoracic duct exhibited significant functional mesenteric lymphatics. To understand molecular basis these differences, we examined profiles contractile proteins their messages in lymphatics, duct, arterioles. Results demonstrated...
To evaluate lymphatic contractile activity in different regions of the system a single animal model (the rat thoracic duct, mesenteric, cervical, and femoral lymphatics) response to changes lymph pressure flow.The systolic diastolic diameters isolated, cannulated, pressurized vessels were measured. Contraction frequency, ejection fraction, fractional pump flow determined. The influences incrementally increased transmural (from 1 9 cm H2O) imposed 5 H2O transaxial gradient) investigated.The...
The objectives of this study were to evaluate the physiological importance flow and shear generated by phasic contractions lymphatic vessels mechanisms responsible for influences such on pumping. Lymphatic segments rat thoracic duct isolated, cannulated pressurized. diastolic diameters measured in phasically non-active segments. systolic diameters, half-relaxation time (HRT), contraction frequency, ejection fraction fractional pump determined active Since imposed was excluded, occurred only...
Secondary lymphatic valves are essential for minimizing backflow of lymph and presumed to gate passively according the instantaneous trans-valve pressure gradient. We hypothesized that valve gating is also modulated by vessel distention, which could alter leaflet stiffness coaptation. To test this hypothesis, we devised protocols measure small gradients required open or close determine if varied as a function diameter. Lymphatic vessels were isolated from rat mesentery, cannulated,...
The role of lymphatic vessels is to transport fluid, soluble molecules, and immune cells the draining lymph nodes. Here, we analyze how aging process affects functionality collectors dynamics flow. Ultrastructural, biochemical, proteomic analysis indicates a loss matrix proteins, smooth muscle in aged resulting decrease contraction frequency, systolic flow velocity, pumping activity, as measured vivo collectors. Functionally, this impairment also translated into reduced ability for bacterial...
Collecting lymphatic vessels share functional and biochemical characteristics with cardiac muscle; thus, we hypothesized that the vessel pump would exhibit behavior analogous to homeometric regulation of in its adaptation elevated afterload, i.e., an increase contractility. Single lymphangions containing two valves were isolated from rat mesenteric microcirculation, cannulated, pressurized for vitro study. Pressures at either end lymphangion [input pressure (P ), preload; output out...
Collecting lymphatic vessels (CLVs), surrounded by fat and endowed with contractile muscle valves, transport lymph from tissues after it is absorbed into capillaries. CLVs are not known to participate in immune responses. In this study, we observed that the inherent permeability of allowed broad distribution components within surrounding for uptake adjacent macrophages dendritic cells (DCs) actively interacted CLVs. Endocytosis lymph-derived Ags these supported recall T cell responses also...
Multiple investigators have shown interdependence of lymphatic contractions on nitric oxide (NO) activity by pharmacological and traumatic suppression endothelial NO synthase (eNOS). We demonstrated that diastolic relaxation is particularly sensitive to from the endothelium. The predicted mechanism shear forces produced lymph flow during phasic pumping, activating eNOS in endothelium produce NO. measured [NO] using microelectrodes situ mesenteric lymphatics anesthetized rats under basal...
To evaluate the age-related changes in pumping of mesenteric lymphatic vessels 9- and 24-month-old male Fisher-344 rats. Lymphatic diameters, contraction amplitude, frequency, fractional pump flow were determined isolated MLV before after l-NAME application. The data demonstrate a severe weakening aged including diminished as result, activity. also suggest that imposed gradient-generated shear-dependent relaxation does not exist rat MLV, sensitivity both adult to such shear cannot be...
Lymphangions, segments of lymphatic vessels bounded by valves, have characteristics both ventricles and arteries. They can act primarily like pumps when actively transporting lymph against a pressure gradient. also as conduit passively down This duality has implications for clinical treatment several types edema, since the strategy to optimize flow may depend on whether it is most beneficial lymphangions or conduits. To address this duality, we employed simple computational model contracting...
To accomplish its normal roles in body fluid regulation/macromolecular homeostasis, immune function, and lipid absorption; the lymphatic system must transport lymph from interstitial spaces, into through lymphatics, compartment of nodes, back nodal efferent lymphatics eventually empty great veins. The usual net pressure gradients along this path do not normally favor passive movement lymph. Thus, requires input energy to propel it path. this, uses a series pumps generate flow. Thus regulate...
Substance P (SP) is a neuropeptide associated with sensory innervation of lymphoid tissue and suspected modulator lymphatic function in inflammation. Only few studies have examined the effects SP on contraction, it not clear to what extent acts directly muscle and/or endothelium or indirectly through changes intraluminal filling pressure secondary increases capillary permeability/filtration. We tested spontaneous contractions rat isolated mesenteric vessels under isometric isobaric...
The objective of study was to evaluate the aging-associated changes, contractile characteristics mesenteric lymphatic vessels (MLV), and lymph flow in vivo male 9- 24-mo-old Fischer-344 rats. Lymphatic diameter, contraction amplitude, frequency, fractional pump flow, velocity, wall shear stress, minute active stress load were determined MLV before after N ω -nitro-l-arginine methyl ester hydrochloride (l-NAME) application at 100 μM. pumping aged rat found be severely depleted, predominantly...
We had previously proposed the presence of permanent stimulatory influences in tissue microenvironment surrounding aged mesenteric lymphatic vessels (MLV), which influence function. In this study, we performed immunohistochemical labeling proteins known to be present mast cells (mast cell tryptase, c-kit, prostaglandin D(2) synthase, histidine decarboxylase, histamine, transmembrane protein 16A, and TNF-α) with double verification same segment rat mesentery containing MLV by Alexa Fluor...
We tested the responses of single, isolated lymphangions to selective changes in preload and effects changing on response an imposed afterload. The methods used were similar those described our companion paper. Step-wise increases input pressure (P ; preload) over a range between 0.5 3 cmH 2 O, at constant output out ), led end-diastolic diameter, decreases end-systolic stroke volume. From baseline 1 P elevation by 2–7 O consistently produced immediate fall volume that subsequently recovered...
Abstract Objectives The knowledge of the basic principles lymphatic function, still remains, to a large degree, rudimentary and will require significant research efforts. Recent studies physiology MLVs suggested presence an EDRF other than NO. In this study, we tested hypothesis that endothelium‐derived histamine relaxes MLVs. Methods We measured analyzed parameters contractility in isolated pressurized rat under control conditions after pharmacological blockade NO by l ‐NAME (100 μ M)...
Many tissues exhibit subatmospheric interstitial pressures under normal physiologic conditions. The mechanisms by which the lymphatic system extracts fluid from these against overall pressure gradient are unknown. We address this important issue combining experimental measurements of contractile function and generation with a previously validated mathematical model. provide definitive evidence for existence 'suction pressure' in collecting vessels, manifests as transient drop downstream...
Abstract Transport of tissue-derived lymphatic fluid and clearance by draining lymph nodes are pivotal for maintenance homeostasis in the body immune-surveillance self- non-self-proteomes. Yet a quantitative analysis nodal filtration proteome present has not been reported. Here we quantified efficiency composite proteomic load using label-free isotope-labeling pre-nodal post-nodal samples collected direct cannulation. These results were extended quantitation fluorophore-labeled proteins,...
We tested the hypothesis that lymphatics would exhibit myogenic constrictions and dilations to intraluminal pressure changes. Collecting lymphatic vessels were isolated from rat mesentery, cannulated, pressurized for in vitro study. The diameter responses controlled steps of different magnitudes absence presence inflammatory mediator substance P, which is known enhance contractility. Myogenic constriction, defined as a time-dependent decrease end-diastolic over 1- 2-min period following...
The passive and active length-tension relationships of isolated rat mesenteric lymphatics ( approximately 150 microm ID), adjacent small arteries 240 microm) veins 275 were compared under isometric conditions using a wire myograph. About 60% the lymphatic vessels developed spontaneous contractions in physiological saline solution at nominal preload. To maximally activate smooth muscle, 145 mM K(+) + 5 x 10(-5) M norepinephrine was used for arteries, 1 10(-6) substance P veins. In response,...