Polymorphonuclear leukocyte activation induces cerebral hypoperfusion in rats in the absence of previous ischemia-reperfusion damage.
We determined if activation of circulating neutrophils could influence local cerebral blood flow (lCBF) and cerebrovascular reactivity without previous ischemic endothelial activation. After intracarotid infusion of phorbol myristate acetate (PMA, twice in 30 min), Laser-Doppler measurements of lCBF in the parietal cortex of anesthetised rats showed a fall of 34% (P<0.05) at 30 min, but not in the vehicle group nor the group predepleted in polymorphonuclear leukocytes (PMNLs). Blood gases or arterial pressure did not change significantly in any group. The PMNL count fell by 78% at 30 min and reactivity to systemic hypercapnia by 58% at 30-60 min post infusion in the PMA group. These results show that activated PMNLs reduce lCBF and vasoreactivity in the absence of previous cerebral ischemia.
Chen
L
L
Laboratory of Cerebrovascular Research, CNRS UPR 646, Faculty of Medecine, Paris University 7, Paris, France.
Vicaut
E
E
Sercombe
R
R
D000818:Animals; D001792:Blood Platelets / Q000187:drug effects; D002540:Cerebral Cortex / Q000098:blood supply* / Q000187:drug effects; D002560:Cerebrovascular Circulation / Q000187:drug effects*; D004121:Dimethyl Sulfoxide / Q000494:pharmacology; D006935:Hypercapnia / Q000503:physiopathology; D007261:Infusions, Intra-Arterial; D008212:Lymphocyte Depletion; D008214:Lymphocytes / Q000187:drug effects; D008297:Male; D009000:Monocytes / Q000187:drug effects; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D011921:Rats, Inbred WKY; D015427:Reperfusion Injury; D013755:Tetradecanoylphorbol Acetate / Q000008:administration & dosage / Q000494:pharmacology*
D013755:Tetradecanoylphorbol Acetate; D004121:Dimethyl Sulfoxide