Single-dose versus two-dose dexamethasone effects on lung inflammation and airway reactivity in meconium-instilled rabbits.
Two doses of the corticosteroid dexamethasone may alleviate meconium-induced acute lung injury more effectively than a single dose. Meconium-instilled rabbits intravenously received dexamethasone (0.5 mg/kg) at one dose 0.5 hours after meconium instillation or at two doses 0.5 hours and 2.5 hours after meconium instillation or were left without treatment, and were oxygen-ventilated for additional 5 hours. At the end of experiment, lungs and trachea were excised. Two doses of dexamethasone effectively diminished meconium-induced lung edema, tracheal hyperreactivity to histamine, neutrophil count in bronchoalveolar lavage fluid, and decreased oxidative modifications of proteins and lipids in lung homogenate compared with the non-treated group. Single-dose dexamethasone also reduced lung edema, lung neutrophils, and tracheal hyperreactivity to histamine, but these effects were weaker than those after two-dose dexamethasone. We conclude that two-dose dexamethasone is superior to single-dose dexamethasone in prevention lung injury in meconium-instilled rabbits.
Mokra
D
D
Department of Physiology, Jessenius Faculty of Medicine, Comenius University, Martin, Slovakia. mokra@jfmed.uniba.sk
Mokry
J
J
Drgova
A
A
Bulikova
J
J
Petraskova
M
M
Calkovska
A
A
D000818:Animals; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage*; D001985:Bronchial Provocation Tests; D016084:Bronchoconstriction / Q000187:drug effects*; D016085:Bronchoconstrictor Agents / Q000008:administration & dosage; D003907:Dexamethasone / Q000008:administration & dosage*; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D006632:Histamine / Q000008:administration & dosage; D006801:Humans; D007231:Infant, Newborn; D007275:Injections, Intravenous; D015227:Lipid Peroxidation / Q000187:drug effects; D008168:Lung / Q000187:drug effects* / Q000378:metabolism / Q000503:physiopathology; D008471:Meconium Aspiration Syndrome / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D020556:Neutrophil Infiltration / Q000187:drug effects; D018384:Oxidative Stress / Q000187:drug effects; D011015:Pneumonia, Aspiration / Q000378:metabolism / Q000503:physiopathology / Q000517:prevention & control*; D050050:Protein Carbonylation / Q000187:drug effects; D011654:Pulmonary Edema / Q000517:prevention & control; D011817:Rabbits; D019141:Respiratory System Agents / Q000008:administration & dosage*; D013997:Time Factors; D014133:Tracheal Diseases / Q000378:metabolism / Q000503:physiopathology / Q000517:prevention & control*
D000893:Anti-Inflammatory Agents; D016085:Bronchoconstrictor Agents; D019141:Respiratory System Agents; D003907:Dexamethasone; D006632:Histamine