Related Experiment Video
Updated: Jul 18, 2026
A Comparative Study of Drug Delivery Methods Targeted to the Mouse Inner Ear: Bullostomy Versus Transtympanic Injection
Published on: March 8, 2017
Transtympanic versus intramuscular steroid administration in a histamine-induced inflammatory middle-ear model
T S Chimona1, J G Panayiotides, C E Papadakis
1Department of Otolaryngology, University of Crete School of Medicine, Crete. chimonath@yahoo.gr
Objectives:
Assessment of the histopathologic effect of transtympanic and intramuscular administration of dexamethasone in an in vivo experimental animal model of middle-ear mucosal inflammation.
Methods:
Fifty healthy rabbits weighting 1500-1800 g were randomly divided in three groups. In 10 animals (control group), 0.5 ml of a 20 mg/ml histamine solution was injected transtympanically. In 20 rabbits (group A), histamine challenge followed a three day intramuscular pretreatment with dexamethasone at 1 mg/kg per day. In 20 rabbits (group B), histamine challenge followed pretreatment with dexamethasone via a transtympanic route (0.3 ml, 1.2 mg dexamethasone). Middle-ear mucosa was obtained for histopathology 30 minutes after histamine administration. The following parameters were assessed: inflammation, acute inflammatory component, presence of eosinophils, inflammatory activity and fibrosis.
Results:
Oedema, vascular dilatation and congestion, inflammation, the presence of an acute (polymorphonuclear) inflammatory component, the presence of eosinophils, and inflammatory activity were found to be of a lesser grade in the mucosae of group B. All differences were found to be statistically highly significant (p<0.01) using the Mann-Whitney test.
Conclusion:
Our findings validate the transtympanic route of dexamethasone administration in counteracting histamine effects.
