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Ketotifen induced inhibition of histamine release in a non‐IgE model of middle ear effusion
Author(s) -
Berger Gilead,
Berger Rachel,
Goldberg Ar
Publication year - 2006
Publication title -
pediatric allergy and immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.269
H-Index - 89
eISSN - 1399-3038
pISSN - 0905-6157
DOI - 10.1111/j.1399-3038.2005.00350.x
Subject(s) - ketotifen , histamine , medicine , stimulation , effusion , immunoglobulin e , mast cell , population , compound 48/80 , edema , group b , degranulation , group a , anesthesia , pathology , immunology , surgery , asthma , receptor , environmental health , antibody
The inhibitory effects of ketotifen, a histamine H1‐receptor antagonist and mast cell stabilizer, were examined on a non‐IgE experimental model of middle ear effusion. Thirty rats were divided into three groups. Group A (n = 9) was subjected to mechanical stimulation of the external auditory canal (EAC); group B (n = 11) was pre‐treated with intraperitoneal administration of 0.2 mg ketotifen, 90 min before mechanical stimulation of the EAC; and group C (n = 10), the control group, was neither exposed to mechanical stimulation nor given ketotifen. Thirty minutes after completion of the experiment, the eardrums were inspected, histamine levels were determined by a fluorometric assay, and the pars flaccida underwent histological assessment. An attic effusion was observed in group A; a similar phenomenon but to a lesser extent was also seen in group B. Statistical analysis confirmed that the mean histamine concentration of the rinsing fluid obtained from group A was significantly higher than that of group C (p = 0.004) or group B (p = 0.008). No significant difference was found between the mean histamine concentration of groups C and group B (p = 0.311). Histological assessment revealed that the thickness of the pars flaccida of group A was considerably greater than that of groups C and B and was characterized by marked edema. Furthermore, the pars flaccida mast cell population was significantly depleted compared with groups C and B. The data indicate that mechanical stimulation of the EAC triggered the pars flaccida mast cells to degranulate in a non‐mediated IgE fashion and that histamine is implicated in most of these histological changes. It is concluded that administration of ketotifen before mechanical stimulation of the EAC had a stabilizing effect and abolished mast cell degranulation, therefore, may be considered as a potential therapeutic agent for the treatment of middle ear disease in the pediatric population.