Related Experiment Videos
Modulation of leukocyte migration in mesenteric interstitium
K Bienvenu1, N Harris, D N Granger
1Department of Physiology and Biophysics, Louisiana State University Medical Center, Shreveport 71130.
Abstract:
Intravital videomicroscopy was used to monitor the migration of leukocytes in rat mesenteric interstitium following exposure of the mesentery to either N-formylmethionyl-leucyl-phenylalanine (FMLP), leukotriene B4 (LTB4), platelet-activating factor (PAF), or ischemia-reperfusion (I-R). All inflammatory stimuli resulted in interstitial migration rates that were higher than those measured in unstimulated extravasated leukocytes. The median migration rate of cells stimulated with FMLP was significantly higher than those observed during superfusion with either LTB4 or PAF or following exposure to I-R. The enhanced leukocyte migration rates elicited by I-R were not attenuated by treatment with PAF- and LTB4-receptor antagonists, suggesting that these lipid mediators are not the inflammatory mediators responsible for I-R-induced leukocyte migration. Additional experiments revealed that the rate of leukocyte migration associated with FMLP stimulation was not significantly altered by either inhibitors of neutrophilic elastase and cathepsin G, a monoclonal antibody directed against the leukocyte adhesion glycoprotein CD11/CD18, or by altering interstitial hydration. This in vivo model provides a useful new approach for defining the factors that modulate leukocyte migration within the extravascular compartment.
Insights
N-formylmethionyl-leucyl-phenylalanine (FMLP) significantly enhances leukocyte migration in rat mesentery interstitium more than other inflammatory stimuli. This study introduces a novel in vivo model for studying extravascular leukocyte movement.
Area of Science:
- Immunology
- Cell Biology
- Physiology
Background:
- Leukocyte migration is crucial in inflammatory responses.
- Understanding extravascular leukocyte movement is vital for disease research.
- Existing models have limitations in studying interstitial leukocyte dynamics.
Purpose of the Study:
- To investigate leukocyte migration rates in the rat mesenteric interstitium.
- To compare the effects of various inflammatory stimuli on leukocyte migration.
- To establish a novel in vivo model for studying extravascular leukocyte dynamics.
Main Methods:
- Intravital videomicroscopy was employed to observe leukocyte migration.
- The rat mesentery was exposed to N-formylmethionyl-leucyl-phenylalanine (FMLP), leukotriene B4 (LTB4), platelet-activating factor (PAF), or ischemia-reperfusion (I-R).
- The impact of receptor antagonists and enzyme inhibitors on migration was assessed.
Main Results:
- All tested inflammatory stimuli increased interstitial leukocyte migration rates compared to controls.
- FMLP stimulation resulted in significantly higher migration rates than LTB4, PAF, or I-R.
- Ischemia-reperfusion-induced migration was not affected by PAF- and LTB4-receptor antagonists.
- FMLP-stimulated migration was unaffected by elastase/cathepsin G inhibitors, anti-CD11/CD18 antibody, or altered interstitial hydration.
Conclusions:
- FMLP is a potent stimulator of leukocyte migration in the mesenteric interstitium.
- LTB4 and PAF are unlikely mediators of ischemia-reperfusion-induced leukocyte migration.
- The developed in vivo model is effective for studying factors influencing extravascular leukocyte migration.