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Penicillin reduces secretory capacity in rat middle ear mucosa in acute otitis media
P Cayé-Thomasen1, A Hermansson, M Tos
1Department of Oto-rhino-laryngology, Gentofte University Hospital of Copenhagen, Denmark.
Abstract:
In the United States, antibiotic treatment of acute otitis media is almost mandatory, whereas several other western countries are more reticent. Most clinical trails on antibiotic effect have important methodologic flaws, making an overall interpretation quite difficult. This study determined the effect of penicillin V administration on the secretory capacity of rat middle ear mucosa, during and after acute pneumococcal otitis media, by quantitative studies of the goblet cell density. The right middle ear bullae of 25 rats were inoculated with type 3 pneumococci. Beginning 2 days after inoculation, penicillin V 100 mg/kg/day was administered orally for 5 days. After inoculation, five randomly selected rats were killed on days 4, 8, 16, 90, and 180. The middle ear bullae were removed, split in half, stained with periodic acid-Schiff (PAS)-alcian blue, and the mucosae dissected from the bone. Whole mounts were prepared and the goblet cell density determined in 24 well-defined localities, making a total of 160 counts per ear and covering the entire bulla mucosa. Goblet cell densities were compared with those of 25 normal ears and 25 inoculated, untreated ears. Except on day 4, the penicillin V-treated ears had a significantly lower goblet cell density in almost all localities, on all days of death, when compared with untreated ears. Six months after the acute incident, the goblet cell density was almost normal. However, the enlargement of the mucosal area containing goblet cells seen in untreated ears was unaffected by penicillin V administration. We conclude that administration of penicillin V reduces the increase in secretory capacity of rat middle ear mucosa during and 6 months after acute pneumococcal otitis media.
Insights
Penicillin V treatment for acute otitis media in rats reduced middle ear mucosal secretory capacity. While goblet cell density normalized over time, the enlarged mucosal area remained, suggesting long-term effects of antibiotic use.
Area of Science:
- Otolaryngology
- Microbiology
- Pharmacology
Background:
- Antibiotic treatment for acute otitis media (AOM) varies globally, with the US favoring mandatory treatment.
- Methodological flaws in clinical trials complicate the interpretation of antibiotic efficacy in AOM.
- The impact of antibiotics on middle ear mucosa's secretory capacity during and after AOM requires further investigation.
Purpose of the Study:
- To investigate the effect of penicillin V on the secretory capacity of rat middle ear mucosa during and after pneumococcal AOM.
- To quantify changes in goblet cell density as an indicator of secretory capacity.
Main Methods:
- Rats with experimentally induced pneumococcal AOM were treated with penicillin V.
- Goblet cell density in the middle ear mucosa was quantitatively assessed using PAS-alcian blue staining at various time points.
- Goblet cell densities were compared between penicillin V-treated, untreated, and normal ears.
Main Results:
- Penicillin V treatment significantly reduced goblet cell density in most areas of the middle ear mucosa compared to untreated ears, except on day 4.
- Goblet cell density approached normal levels six months post-infection.
- The antibiotic did not affect the enlargement of the mucosal area containing goblet cells observed in untreated ears.
Conclusions:
- Penicillin V administration decreases the increased secretory capacity of rat middle ear mucosa during and six months after acute pneumococcal otitis media.
- While penicillin V impacts goblet cell density, it does not fully reverse the mucosal area enlargement, indicating potential long-term changes.