The present study investigated the local effect of PAP on the middle ear
of experimental animals. The study was conducted on 30 albino non lined
rats 10 of which served as control (group I). The other 20 animals were divided
into two groups(group H and 110. In which PAP was injected in the
right hypotympartic bullae in a dose of 16 mg. The electron-microscopic
changes of the mucoperiosteal tinning of group H were studied after 2
days and that of the group HI were studied after 2 weeks.
All the animals injected with PAP in their middle ear developed otitis
media with effusion after 2 days. The middle ear mucosa exhibited subepithelial
hemorrhagic foci, hyperemia, edema, leucocytic infiltration and
beginning of osteogenesis was observed. A degree of inflammation was
elicited in all operated ears.
Two weeks after PAP injection (group H), the same changes seen in
group H were also seen but were of mild severity. The presence of neoosteogenesis
was detected by the presence of modified fibroblasts in their
way to be changed into osteoblasts and osteocytes. It could be concluded
that PAP plays an important role in the pathogenesis of otitis media with
effusion (OME). The effect of PAP is marked after few days and can last
for 14 days but the effect becomes less marked. Study of the effect of
anti-PAP on OME is recommended |
