Related Experiment Videos
Further studies on passive peritoneal anaphylaxis in the rat
International Archives of Allergy and Applied Immunology
|January 1, 1977
Summary
H1 antihistamines and adrenoceptor stimulants inhibited protein extravasation in rats without affecting histamine release. Other agents required higher doses, suggesting distinct mechanisms in passive peritoneal anaphylaxis.
Area of Science:
- Pharmacology
- Immunology
- Allergy Research
Background:
- Passive peritoneal anaphylaxis (PPA) in rats is a model for studying allergic responses.
- Histamine release is a key mediator in anaphylaxis, leading to protein extravasation.
Purpose of the Study:
- To investigate the mechanisms by which different compounds affect protein extravasation during PPA.
- To differentiate between histamine-dependent and independent pathways in PPA.
Main Methods:
- Administration of H1 antihistamines, adrenoceptor stimulants, aminophylline, non-steroidal anti-inflammatory agents, disodium cromoglycate (DSCG), and BRL 10833 to rats prior to PPA induction.
- Measurement of serum protein extravasation into peritoneal fluid.
- Assessment of histamine release levels.
Main Results:
- H1 antihistamines and adrenoceptor stimulants inhibited extravasation at doses that did not affect histamine release.
- Aminophylline and NSAIDs inhibited extravasation only at doses that also inhibited histamine release, similar to DSCG and BRL 10833 but less potent.
- Pre-dosing with DSCG reduced the efficacy of subsequent DSCG, BRL 10833, and indomethacin, suggesting a shared pathway for these agents.
Conclusions:
- H1 antihistamines and adrenoceptor stimulants likely act via a histamine-independent pathway in PPA.
- Aminophylline, NSAIDs, DSCG, and BRL 10833 may involve histamine-related or common pathways, with DSCG, BRL 10833, and indomethacin sharing a specific pathway.
- The study found no evidence of histamine 'feedback' inhibition of histamine release in the rat PPA model.