Influence of chronic unpredictable stress on the allergic responses in rats.
The effects of chronic unpredictable stress on airway leukocyte infiltration and plasma extravasation in female rats have been investigated. The chronic stress lasted for 14 days and consisted of transitory and variable changes in the living conditions of the animals. Concomitant to the stress procedure, the animals were sensitized (Day 0) and challenged with ovalbumin (OVA; 200 microg) at Day 14. Bronchoalveolar lavage (BAL) was performed 48 h after intratracheal challenge with OVA (0.4 ml of a 0.25% solution). The increase in plasma extravasation was assessed by the rat paw oedema induced by OVA (0.1 mg/paw) or the mast cell degranulator compound 48/80 (5 microg/paw). A significant increase (P < .05) in the total leukocyte influxes into the airways was observed in the stressed (sensitized) group compared to nonstressed (sensitized) animals, and this was associated with a marked recruitment of eosinophils and mononuclear cells in the BAL fluid. In OVA-sensitized rats, intraplantar injection of OVA induced a marked paw oedema that was significantly higher in stressed compared to nonstressed groups. In contrast to OVA, the compound 48/80 (5 microg/paw)-induced oedema did not significantly differ between nonstressed and stressed groups. Our results indicate that chronic unpredictable stress exacerbates the vascular and cellular inflammatory responses.
Datti
Fernanda
F
Faculty of Medical Sciences, Department of Pharmacology, UNICAMP, P.O. Box 6111, 13081-970, Campinas (SP), Brazil.
Datti
Marcelo
M
Antunes
Edson
E
Teixeira
Nancy A
NA
D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D005260:Female; D006967:Hypersensitivity / Q000097:blood / Q000150:complications* / Q000473:pathology / Q000503:physiopathology*; D007958:Leukocyte Count; D010047:Ovalbumin / Q000097:blood / Q000493:pharmacokinetics; D051381:Rats; D017208:Rats, Wistar; D013312:Stress, Physiological / Q000150:complications*; D003189:p-Methoxy-N-methylphenethylamine / Q000097:blood / Q000493:pharmacokinetics
D003189:p-Methoxy-N-methylphenethylamine; D010047:Ovalbumin