Leukocyte-endothelium-interaction in pial vessels following global, cerebral ischaemia.
BACKGROUND
Investigations have shown an increase of leukocyte-endothelium-interaction in a variety of organs following an ischaemic insult. To elucidate the role of leukocyte-endothelium-interaction following global, cerebral ischaemia the present study was performed.


METHODS
Global, cerebral ischaemia was induced for twenty minutes by four-vessel-occlusion (PULSINELLI). Leukocyte-endothelium-interaction was studied in the cerebral microcirculation using a rat closed cranial window and intravital microscopy. Leukocytes were stained intravenously using rhodamine 6G. Diameters of pial vessels, leukocyte centreline velocity and number of rolling or adhering leukocytes were determined off-line up to 2 h following global cerebral ischaemia. To confirm these results immunohistochemistry of the brain was performed.


RESULTS
Four-vessel-occlusion induced an iso-electric EEG, venular stasis and minimal rest flow in arterioles. Reperfusion yielded a significant increase of the arteriolar (p < 0.001) and a smaller increase of the venular diameters (p < 0.01). Up to 2 h after ischaemia no significant increase of the number of rolling or adhering leukocytes was measured which was confirmed by immunohistochemistry.


CONCLUSIONS
In contrast to other studies, in particular regarding focal cerebral ischaemia, an increase of leukocyte-endothelium-interaction in rat brain following 20 min of global cerebral ischaemia was not observed despite histological evidence of ischaemic damage. Thus in our model leukocytes seem not to contribute to the brain damage following global ischaemia.
Abels
C
C
Institute for Surgical Research, Klinikum Grosshadern, Ludwig-Maximilians-University Munich, Germany.
Röhrich
F
F
Corvin
S
S
Meyermann
R
R
Baethmann
A
A
Schürer
L
L
D000818:Animals; D001783:Blood Flow Velocity / Q000502:physiology; D001925:Brain Damage, Chronic / Q000473:pathology; D002545:Brain Ischemia / Q000473:pathology*; D002448:Cell Adhesion / Q000502:physiology; D004730:Endothelium, Vascular / Q000473:pathology*; D007958:Leukocyte Count; D007962:Leukocytes / Q000473:pathology*; D008297:Male; D008833:Microcirculation / Q000473:pathology; D010841:Pia Mater / Q000098:blood supply*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015427:Reperfusion Injury / Q000473:pathology*; D014655:Vascular Resistance / Q000502:physiology