Acute ischemic stroke : polymorphonuclear leukocyte membrane fluidity and cytosolic Ca(2+) concentration at baseline and after chemotactic activation.
OBJECTIVE
Several reports have considered the role of systemic leukocytes in acute ischemic stroke (AIS). Initially, greater attention was focused on the leukocyte count and subsequently on their adhesiveness, aggregation, rheology, and activation. The aim of this study was the evaluation of certain polymorphonuclear leukocyte (PMN) parameters, reflecting their rheology and activation, in subjects with AIS.


METHODS
In a group of 19 subjects with AIS and in a control group of 18 subjects with asymptomatic vascular atherosclerotic disease, we evaluated the PMN membrane fluidity and cytosolic Ca(2+) concentration at baseline and after in vitro chemotactic activation with 4-phorbol 12-myristate 13-acetate (PMA) and N-formyl-methionyl-leucyl-phenylalanine (fMLP).


RESULTS
From the obtained data, it is evident that at baseline only PMN membrane fluidity distinguishes control subjects from AIS subjects. After PMN activation with PMA and fMLP, prolonged for 5 and 15 minutes, we found an increase in PMN cytosolic Ca(2+) concentration and a decrease in PMN membrane fluidity only in subjects with AIS.


CONCLUSIONS
These findings emphasize that in subjects with AIS a functional alteration of systemic PMN cells is clearly expressed during chemotactic activation, although the mechanism of this abnormality is not yet explained.
Caimi
G
G
Istituto di Clinica Medica e Malattie Cardiovascolari, Università degli Studi di Palermo, Palermo, Italy.
Ferrara
F
F
Montana
M
M
Meli
F
F
Canino
B
B
Carollo
C
C
Presti
R L
RL
D000208:Acute Disease; D000368:Aged; D000369:Aged, 80 and over; D002545:Brain Ischemia / Q000276:immunology*; D002118:Calcium / Q000032:analysis*; D002633:Chemotaxis / Q000276:immunology*; D003600:Cytosol / Q000276:immunology; D005260:Female; D006801:Humans; D008297:Male; D008560:Membrane Fluidity / Q000276:immunology*; D008875:Middle Aged; D018375:Neutrophil Activation; D009504:Neutrophils / Q000737:chemistry / Q000166:cytology / Q000276:immunology*; D020521:Stroke / Q000276:immunology*
D002118:Calcium