Effects of diazepam and stress on lung inflammatory response in OVA-sensitized rats

• Published in: American journal of physiology. Lung cellular and molecular physiology 2002-06, Vol.282 (6), p.1289-L1295
• Main Authors: Portela, Carlos De Paula, Tiberio, Iolanda De F. L. C, Leick-Maldonado, Edna A, Martins, Milton A, Palermo-Neto, Joao
• Format: Article
• Language: English
• Subjects: Administration, Inhalation; Anaphylaxis - complications; Anaphylaxis - immunology; Animals; Anti-Anxiety Agents - pharmacology; Bronchial Diseases - complications; Bronchial Diseases - immunology; Bronchial Diseases - pathology; Conditioning (Psychology); Diazepam - pharmacology; Edema - complications; Edema - immunology; Edema - pathology; Electroshock; Injections, Intraperitoneal; Lung - drug effects; Lung - immunology; Lung - pathology; Male; Ovalbumin - administration & dosage; Ovalbumin - immunology; Pneumonia - complications; Pneumonia - immunology; Pneumonia - pathology; Rats; Rats, Wistar; Specific Pathogen-Free Organisms; Stress, Physiological - drug therapy; Stress, Physiological - immunology
• ISSN: 1040-0605; 1522-1504
• DOI: 10.1152/ajplung.00352.2001

1  Applied Pharmacology and Toxicology Laboratory, School of Veterinary Medicine; and 2  Department of Medicine, School of Medicine, University of São Paulo, São Paulo, Brazil 05508-900 The influence of stress and diazepam treatment on airway inflammation was investigated in ovalbumin (OVA)-sensitized rats. Animals were injected with OVA plus aluminum hydroxide intraperitoneally ( day 0 ) and boosted with OVA subcutaneously ( day 7 ). From the first to 13th day after sensitization, rats were treated with diazepam, and 1 h later they were placed in a shuttle box where they received 50 mild escapable foot shocks/day preceded by a sound signal (S). Response during the warning (S) canceled shock delivery and terminated the S. On day 14 , rats were submitted to a single session of 50 inescapable foot shocks preceded by S and then were challenged with OVA. High levels of stress were detected in shocked animals, manifested as ultrasonic vocalizations. Morphometric analysis of stressed animals revealed a significant increase in both edema and lymphomononucleated cells in airways compared with controls. Diazepam treatment reduced edema in stressed and nonstressed rats. No differences were found in polymorphonucleated cell infiltration. Diazepam treatment reduced lymphomononucleated cell infiltration in stressed animals. These data suggest that stress and diazepam treatment play relevant roles in edema and lymphomononucleated airway inflammation in OVA-sensitized rats. ovalbumin; allergic inflammation; peribronchial edema; lymphomononucleated cells; aversive stimulation; asthma