2.1 Establishment of animal model
The OME animal model was established according to a previous study by
Hardy et al. [10], which were modified slightly, as follows:
Model group (OME Group) was intraperitoneally injected with 10mg
Ovalbumin (Sigma-Aldrich, US) which was dissolved in 0.8ml PBS phosphate
buffer (0.01M, pH7.4) plus 5.14mg aluminum hydroxide gel adjuvant, once
a week for 2 weeks. 2 weeks after receiving chloramine (100 mg/ml) +
stability (5 mg/ml) by intraperitoneal injection of 2:1 mixture (3
ml/kg) depth of anesthesia, the supine position, under the operating
microscope is equal to the level of hyoid, a crosscutting was done for
separation of hyoid scapula muscle and hyoid bone muscle to expose
double ear, bubble bottom wall respectively, aseptic technique was used
to trace syringe. OVA 2 mg of 50 uL PBS liquid was injected into
bilateral listen to bubble, which is ear stimulating stage (before
injection, about 2 mm hole was made from the injection site to balance
the middle ear cavity injection pressure and prevents the tympanic
membrane rupture). Gelatine sponge was inserted to prolong OVA duration.
After injection, 2 small holes were sealed with bone wax, which was the
intraaural stimulation stage. Control group (CON) was sensitized with
PBS. Intramuscular injection of penicillin prevented bacterial infection
before stimulation. After the operation, animals were sacrificed 2 days
after feeding in cages in a clean environment. The researchers did not
know the allocation of groups when evaluating the results. All animals
were treated in accordance with the guidelines for the use of
experimental animals which were approved by the Ethnic Committee of
Shenzhen Longgang E.N.T Hospital (Shenzhen Otorhinolaryngology
Institute).