Dexamethasone attenuates grain sorghum dust extract-induced increase in macromolecular efflux in vivo.
The purpose of this study was to determine whether dexamethasone attenuates grain sorghum dust extract-induced increase in macromolecular efflux from the in situ hamster cheek pouch and, if so, whether this response is specific. By using intravital microscopy, we found that an aqueous extract of grain sorghum dust elicited significant, concentration-dependent leaky site formation and increase in clearance of FITC-labeled dextran (FITC-dextran; mol mass, 70 kDa) from the in situ hamster cheek pouch (P < 0.05). This response was significantly attenuated by dexamethasone (10 mg/kg iv). Dexamethasone also attenuated substance P-induced leaky site formation and increase in clearance of FITC-dextran from the cheek pouch but had no significant effects on adenosine-induced responses. Dexamethasone had no significant effects on arteriolar diameter in the cheek pouch. On balance, these data indicate that dexamethasone attenuates grain sorghum dust extract- and substance P-induced increases in macromolecular efflux from the in situ hamster cheek pouch in a specific fashion.
Akhter
S R
SR
Department of Medicine, University of Illinois at Chicago, and West Side Department of Veterans Affairs Medical Center, Chicago, Illinois 60612, USA.
Ikezaki
H
H
Gao
X P
XP
Rubinstein
I
I
D000241:Adenosine / Q000494:pharmacology; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D001160:Arterioles / Q000187:drug effects; D006224:Cricetinae; D003907:Dexamethasone / Q000494:pharmacology*; D003911:Dextrans; D004391:Dust / Q000009:adverse effects*; D002523:Edible Grain / Q000009:adverse effects*; D016650:Fluorescein-5-isothiocyanate / Q000031:analogs & derivatives; D008297:Male; D008647:Mesocricetus; D008833:Microcirculation / Q000187:drug effects; D009061:Mouth Mucosa / Q000098:blood supply / Q000187:drug effects / Q000378:metabolism; D012039:Regional Blood Flow / Q000187:drug effects; D013373:Substance P / Q000494:pharmacology; D014665:Vasodilator Agents / Q000494:pharmacology
D000893:Anti-Inflammatory Agents; D003911:Dextrans; D004391:Dust; D014665:Vasodilator Agents; C015219:fluorescein isothiocyanate dextran; D013373:Substance P; D003907:Dexamethasone; D016650:Fluorescein-5-isothiocyanate; D000241:Adenosine