Spatial variation of plasma flow in the oxazolone-stimulated microcirculation.
BACKGROUND
In cutaneous lymphocytic inflammation, enhanced regional blood flow is suggested by persistent erythema and warmth. Direct assessment of the microcirculation, however, has been limited by tissue edema and skin thickness.


METHODS
To assess the microcirculatory adaptations to the epicutaneous antigen oxazolone, we studied the first pass kinetics and microvascular topography of the inflammatory skin microcirculation using a specially adapted epi-illumination intravital microscopy system. The fluorescence intravital videomicroscopy and streaming image acquisition of fluorescein-labeled dextran (approximately 500,000 MW) injections were used to assess changes in plasma flow.


RESULTS
Direct plasma tracer injections of both the oxazolone-stimulated and control microcirculation demonstrated comparable transit times (leading edge and intensity-weighted peak times) from the carotid artery to the superficial vascular plexus (p > 0.05). In contrast to transit times, continuous infusion of the plasma tracer demonstrated a significant increase in the delivery of the fluorescein-labeled dextran to the oxazolone-stimulated microcirculation. Quantitative morphometry of intravital microscopic images demonstrated a 2.2-fold increase in the mean diameter of vessels in the superficial vascular plexus (p < 0.01). Further, fluorescence intensity mapping indicated that the increase was associated with increased perfusion of focal regions of the superficial vascular plexus (p < 0.001).


CONCLUSIONS
These results indicate that the oxazolone-stimulated adaptations of the inflammatory microcirculation include both microvascular dilatation and the redistribution of plasma flow.
West
C A
CA
Laboratory of Immunophysiology, Dana-Farber Cancer Institute and Harvard Surgical Research Laboratories, Harvard Medical School, 75 Francis Street, Boston MA 02115, USA.
He
C
C
Young
A J
AJ
Su
M
M
Zhao
T
T
Swanson
S J
SJ
Mentzer
S J
SJ
D000818:Animals; D002196:Capillaries / Q000033:anatomy & histology / Q000187:drug effects; D004396:Coloring Agents; D004801:Eosine Yellowish-(YS); D004890:Erythema / Q000473:pathology; D005456:Fluorescent Dyes; D006416:Hematoxylin; D008214:Lymphocytes / Q000187:drug effects; D008833:Microcirculation / Q000187:drug effects; D008856:Microscopy, Fluorescence; D010080:Oxazoles / Q000494:pharmacology*; D012039:Regional Blood Flow / Q000187:drug effects; D012756:Sheep; D012867:Skin / Q000098:blood supply* / Q000187:drug effects; D013268:Stimulation, Chemical
D004396:Coloring Agents; D005456:Fluorescent Dyes; D010080:Oxazoles; D004801:Eosine Yellowish-(YS); D006416:Hematoxylin