title: Lymph transport in rat mesenteric lymphatics experiencing edemagenic stress.
abstract: OBJECTIVE
  To assess lymphatic flow adaptations to edema, we evaluated lymph transport function in rat mesenteric lymphatics under normal and increased fluid volume (edemagenic) conditions in situ.
  
  
  METHODS
  Twelve rats were infused with saline (intravenous infusion, 0.2 mL/min/100 g body weight) to induce edema. We intravitally measured mesenteric lymphatic diameter and contraction frequency, as well as lymphocyte velocity and density before, during, and after infusion.
  
  
  RESULTS
  A 10-fold increase in lymphocyte velocity (0.1-1 mm/s) and a sixfold increase in flow rate (0.1-0.6 μL/min), were observed post infusion, respectively. There were also increases in contraction frequency and fractional pump flow one minute post infusion. Time-averaged wall shear stress increased 10 fold post infusion to nearly 1.5 dynes/cm(2) . Similarly, maximum shear stress rose from 5 to 40 dynes/cm(2) .
  
  
  CONCLUSIONS
  Lymphatic vessels adapted to edemagenic stress by increasing lymph transport. Specifically, the increases in lymphatic contraction frequency, lymphocyte velocity, and shear stress were significant. Lymph pumping increased post infusion, though changes in lymphatic diameter were not statistically significant. These results indicate that edemagenic conditions stimulate lymph transport via increases in lymphatic contraction frequency, lymphocyte velocity, and flow. These changes, consequently, resulted in large increases in wall shear stress, which could then activate NO pathways and modulate lymphatic transport function.
authors.affiliation: Center for Translational Injury Research, Department of Surgery, University of Texas Health Science Center, Houston, Texas, USA.
authors.forename: Elaheh
authors.initials: E
authors.lastname: Rahbar
authors.forename: Tony
authors.initials: T
authors.lastname: Akl
authors.forename: Gerard L
authors.initials: GL
authors.lastname: Coté
authors.forename: James E
authors.initials: JE
authors.lastname: Moore
authors.forename: David C
authors.initials: DC
authors.lastname: Zawieja
mesh_terms: D000818:Animals; D001693:Biological Transport, Active; D004487:Edema / Q000378:metabolism / Q000503:physiopathology; D008196:Lymph / Q000378:metabolism*; D008214:Lymphocytes / Q000378:metabolism*; D008297:Male; D008643:Mesentery / Q000378:metabolism / Q000503:physiopathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013312:Stress, Physiological
keywords: contraction frequency; flow rate; lymphedema; shear stress