| Full text | |
| Author(s): |
Zarzana, Eduardo C.
[1]
;
Basso, Alexandre S.
[1]
;
Costa-Pinto, Frederico A.
[1]
;
Palermo-Neto, Joao
[1]
Total Authors: 4
|
| Affiliation: | [1] Univ Sao Paulo, Sch Vet Med, Dept Pathol, Lab Pharmacol & Toxicol, Sao Paulo - Brazil
Total Affiliations: 1
|
| Document type: | Journal article |
| Source: | NEUROIMMUNOMODULATION; v. 16, n. 1, p. 19-27, 2009. |
| Web of Science Citations: | 6 |
| Abstract | |
Background: Mice allergic to ovalbumin (OVA) avoid drinking a solution containing this antigen. This was interpreted as related to IgE-dependent mast cell degranulation and sensory C fiber activation. Methods: We employed pharmacological manipulation to further investigate the mediators involved in immune-induced food aversion. Results: While nonimmunized rats preferred a sweetened OVA solution, immunized rats avoided it. We also employed a paradigm in which rats are conditioned to drink water for two 10-min sessions a day. Tolerant rats presented lower IgE titers, and this manipulation abrogated food aversion. Dexamethasone (1.0 mg/kg) prevented the aversion of OVA-immunized rats to the antigen-containing solution. Combined blockade of H(1) and 5-hydroxytryptamine (5-HT)(2) receptors by promethazine (3.0 mg/kg) plus methysergide (5.0 mg/kg) was unable to alter food aversion. Blockade of 5-HT(3) receptors by ondansetron (1.0 mg/kg) caused a twofold increase in the ingestion of the sweetened OVA solution by immunized rats, suggesting the involvement of 5-HT(3) receptors in food aversion. Finally, we showed that dexamethasone or promethazine plus methysergide, but not ondansetron, effectively prevented the IgE-dependent mast-cell-degranulation-induced increase in vascular permeability in rats. Conclusion: We suggest that regardless of whether or not they cause edema, IgE-mediated mast cell degranulation and consequent 5-HT(3) signaling are involved in the process that triggers avoidance to the source of the allergen in allergic rats. Copyright (C) 2008 S. Karger AG, Basel (AU) | |
| FAPESP's process: | 04/14128-0 - Neuroimmunomodulation: effects of drugs, stress and cytocines on central nervous and immune systems bidirectional relationships |
| Grantee: | João Palermo Neto |
| Support Opportunities: | Research Projects - Thematic Grants |