J. Tanabe et al., POSSIBLE ROLES OF PROTEIN-KINASES IN NEUTROPHIL CHEMOTACTIC FACTOR PRODUCTION BY LEUKOCYTES IN ALLERGIC INFLAMMATION IN RATS, British Journal of Pharmacology, 113(4), 1994, pp. 1480-1486
1 In an air pouch-type allergic inflammation model in rats, leucocytes
that had infiltrated into the pouch fluid collected 4h after the anti
gen challenge produced proteinaceous chemotactic factors for neutrophi
ls when they were incubated in the medium. 2 To clarify the mechanism
of activation of the infiltrated leucocytes in producing these factors
, the effects of protein kinase inhibitors on neutrophil chemotactic f
actor production were examined. 3 When the infiltrated leucocytes were
incubated for 4h in medium containing the non-selective protein kinas
e inhibitor K-252a (1-100 ng ml(-1), 2.14-214 nM), the tyrosine kinase
inhibitor genistein (1-50 mu g ml(-1), 3.7-185 mu M), and the more se
lective protein kinase C inhibitor H-7 (5-100 mu g ml(-1), 13.7-274 mu
M); neutrophil chemotactic activity in the conditioned medium was dec
reased in a concentration-dependent manner, but the adenosine 3':5'-cy
clic monophosphate (cAMP)-dependent protein kinase inhibitor H-89 (1-1
000 ng ml(-1), 2.24-2240 nM) showed no effect. 4 Isoelectric focusing
of the conditioned medium revealed that the leucocytes produced two ne
utrophil chemotactic factors, leucocyte-derived neutrophil chemotactic
factor (LDNCF) 1 and LDNCF-2. Treatment of the leucocytes with K-252a
, genistein, and H-7, but not H-89, inhibited production of both LDNCF
-1 and LDNCF-2. 5 These results suggest that activation of tyrosine ki
nase and protein kinase C, but not cAMP-dependent protein kinase, is r
esponsible for the production of LDNCF-1 and LDNCF-2. 6 The steroidal
anti-inflammatory drug dexamethasone and the protein synthesis inhibit
or cycloheximide inhibited neutrophil chemotactic factor production in
a concentration-dependent manner. Time-course experiments showed that
the inhibitory effect by dexamethasone was apparent even 30 min after
the incubation.7 Mechanism for inhibiting the production of LDNCF-1 a
nd LDNCF-2 by dexamethasone is also discussed.