Dexamethasone inhibits the production of macrophage inflammatory protein 2 in the leukocytes in rat allergic inflammation.
In the air pouch-type allergic inflammation model in rats, when the infiltrated leukocytes in the pouch fluid collected 4 h after antigen challenge were incubated, neutrophil chemotactic activity in the conditioned medium increased time-dependently. They produced neutrophil chemotactic factors, viz. leukocyte-derived neutrophil chemotactic factor (LDNCF)-2, a major component, and LDNCF-1, a minor component. When the infiltrated leukocytes were incubated in the presence of dexamethasone, neutrophil chemotactic activity in the conditioned medium decreased in a concentration-dependent manner, and production of LDNCF-2 and LDNCF-1 was inhibited. Because purified LDNCF-2 had been found to be identical with rat macrophage inflammatory protein 2 (MIP-2), effects of dexamethasone on the level of MIP-2 mRNA in the leukocytes were investigated. Using the reverse transcription-polymerase chain reaction technique, it was demonstrated that dexamethasone suppressed the level of MIP-2 mRNA in the leukocytes. These results indicate that dexamethasone inhibits MIP-2 production at the transcription level.
Tanabe
J
J
Department of Pathophysiological Biochemistry, Faculty of Pharmaceutical Sciences, Tohoku University, Miyagi, Japan.
Watanabe
M
M
Mue
S
S
Ohuchi
K
K
D000818:Animals; D001483:Base Sequence; D002478:Cells, Cultured; D054426:Chemokine CXCL2; D002630:Chemotactic Factors / Q000096:biosynthesis; D003907:Dexamethasone / Q000494:pharmacology*; D006967:Hypersensitivity / Q000378:metabolism*; D007249:Inflammation / Q000378:metabolism*; D007962:Leukocytes / Q000378:metabolism*; D008297:Male; D008969:Molecular Sequence Data; D015846:Monokines / Q000096:biosynthesis* / Q000235:genetics; D009504:Neutrophils / Q000187:drug effects / Q000502:physiology; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley
D054426:Chemokine CXCL2; D002630:Chemotactic Factors; D015846:Monokines; D012333:RNA, Messenger; D003907:Dexamethasone