Structural adaptations in the murine colon microcirculation associated with hapten-induced inflammation.
BACKGROUND
Blood flowing across the vascular endothelium creates wall shear stress, dependent on velocity of flow and vessel geometry, that tends to disrupt lymphocyte-endothelial cell adhesion.


OBJECTIVE
The microcirculation in a murine model of acute colitis was investigated to identify structural adaptations during acute colitis that may facilitate transmigration.


METHODS
In 2,4,6-trinitrobenzenesulphonic acid-induced acute colitis, the infiltrating cells and colonic microcirculation was investigated by cellular topographic mapping, corrosion casting and three-dimensional scanning electron microscopy (SEM). Colonic blood velocimetry was performed using intravital microscopy.


RESULTS
Clinical and histological parameters suggested a peak inflammatory response at 96 h (p<0.001). The infiltrating cells were spatially related to the mucosal capillary plexus by three-dimensional topographic mapping (p<0.001). In normal mice, corrosion casting and three-dimensional SEM showed a polygonal mucosal plexus supplied by ascending arteries and descending veins. After 2,4,6-trinitrobenzenesulphonic acid stimulation, three-dimensional SEM showed preserved branch angles (p = 0.52) and nominal vessel lengths (p = 0.93), but a significantly dilated mucosal capillary plexus (p<0.001). Intravital microscopy of the mucosal plexus showed a greater than twofold decrease in the velocity of flow (p<0.001).


CONCLUSIONS
The demonstrable slowing of the velocity of flow despite an increase in volumetric flow suggests that these microvascular adaptations create conditions suitable for leucocyte adhesion and transmigration.
Ravnic
Dino J
DJ
Laboratory of Immunophysiology, Brigham & Women's Hospital, Boston, Massachusetts 02115, USA.
Konerding
Moritz A
MA
Tsuda
Akira
A
Huss
Harold T
HT
Wolloscheck
Tanja
T
Pratt
Juan P
JP
Mentzer
Steven J
SJ
D000208:Acute Disease; D000222:Adaptation, Physiological; D000818:Animals; D001783:Blood Flow Velocity; D003092:Colitis / Q000139:chemically induced / Q000473:pathology* / Q000503:physiopathology; D003106:Colon / Q000098:blood supply* / Q000000981:diagnostic imaging; D016319:Corrosion Casting; D004195:Disease Models, Animal; D006241:Haptens; D021621:Imaging, Three-Dimensional; D007413:Intestinal Mucosa / Q000098:blood supply / Q000648:ultrastructure; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008833:Microcirculation / Q000000981:diagnostic imaging; D008855:Microscopy, Electron, Scanning; D010853:Picryl Chloride; D012039:Regional Blood Flow; D014463:Ultrasonography
D006241:Haptens; D010853:Picryl Chloride