The effect of aprotinin on hypoxia-reoxygenation-induced changes in neutrophil and endothelial function.
OBJECTIVE
An acute inflammatory response associated with cerebral ischaemia-reperfusion contributes to the development of brain injury. Aprotinin has potential, though unexplained, neuroprotective effects in patients undergoing cardiac surgery.


METHODS
Human neutrophil CD11 b/CD18, endothelial cell intercellular adhesion molecule-1 (ICAM-1) expression and endothelial interleukin (IL)-1beta supernatant concentrations in response to in vitro hypoxia-reoxygenation was studied in the presence or absence of aprotinin (1600 KIU mL(-1)). Adhesion molecule expression was quantified using flow cytometry and IL-1beta concentrations by enzyme-linked immunosorbent assay. Data were analysed using ANOVA and post hoc Student-Newman-Keuls test as appropriate.


RESULTS
Exposure to 60-min hypoxia increased neutrophil CD11b expression compared to normoxia (170+/-46% vs. 91+/-27%, P = 0.001) (percent intensity of fluorescence compared to time 0) (n = 8). Hypoxia (60 min) produced greater upregulation of CD11b expression in controls compared to aprotinin-treated neutrophils [(170+/-46% vs. 129+/-40%) (P = 0.04)] (n = 8). Hypoxia-reoxygenation increased endothelial cell ICAM-1 expression (155+/-3.7 vs. 43+/-21 mean channel fluorescence, P = 0.0003) and IL-1beta supernatant concentrations compared to normoxia (3.4+/-0.4 vs. 2.6+/-0.2, P = 0.02) (n = 3). Hypoxia-reoxygenation produced greater upregulation of ICAM- 1 expression [(155+/-3.3 vs. 116+/-0.7) (P = 0.001)] and IL-1beta supernatant concentrations [(3.4+/-0.3 vs. 2.6+/-0.1) (P = 0.01)] in controls compared to aprotinin-treated endothelial cell preparation (n = 3).


CONCLUSIONS
Hypoxia-reoxygenation-induced upregulation of neutrophil CD11b, endothelial cell ICAM-1 expression and IL-1beta concentrations is decreased by aprotinin at clinically relevant concentrations.
Harmon
D
D
Cork University Hospital, Department of Anaesthesia and Intensive Care Medicine, Cork, Ireland. dharmon@indigo.ie
Lan
W
W
Shorten
G
G
D000704:Analysis of Variance; D007611:Aprotinin / Q000494:pharmacology*; D002545:Brain Ischemia / Q000378:metabolism*; D002448:Cell Adhesion / Q000187:drug effects / Q000502:physiology; D015815:Cell Adhesion Molecules / Q000187:drug effects / Q000378:metabolism; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005434:Flow Cytometry / Q000379:methods; D006490:Hemostatics / Q000494:pharmacology*; D006801:Humans; D066298:In Vitro Techniques; D018799:Intercellular Adhesion Molecule-1 / Q000187:drug effects / Q000378:metabolism; D007375:Interleukin-1 / Q000378:metabolism; D009504:Neutrophils / Q000187:drug effects* / Q000378:metabolism; D012016:Reference Values; D015424:Reperfusion / Q000379:methods; D015427:Reperfusion Injury / Q000378:metabolism; D013997:Time Factors; D014471:Umbilical Veins
D015815:Cell Adhesion Molecules; D006490:Hemostatics; D007375:Interleukin-1; D018799:Intercellular Adhesion Molecule-1; D007611:Aprotinin