Steroid control of acute middle ear inflammation in a mouse model.
OBJECTIVE
To investigate steroids for their potential for therapeutic approaches to control otitis media. Glucocorticoids and mineralocorticoids have differential effects on inflammation and fluid absorption, but little is known of their control of middle and inner ear manifestations of acute otitis media.


METHODS
Both glucocorticoid (prednisolone and dexamethasone) and mineralocorticoid (aldosterone and fludrocortisone) steroids were investigated for their ability to reduce inflammatory symptoms in a mouse otitis media model.


METHODS
Academic medical center.


METHODS
Acute inflammation was induced by transtympanic injection of heat killed Streptococcus pneumoniae to 100 BALB/c mice.


METHODS
Twenty mice in each experimental group (prednisolone, dexamethasone, aldosterone, and fludrocortisone) were given a steroid in their drinking water the day before inoculation, and these treatments were continued until the mice were killed for histologic examination. Twenty control mice were treated with water only.


METHODS
Histologic measure of inflammation: middle ear fluid, inflammatory cell number, and tympanic membrane thickness.


RESULTS
Histologic middle ear morphometrics showed significant steroid effects at both 3 and 5 days in reduction of fluid area, cell number, and tympanic membrane thickness.


CONCLUSIONS
Glucocorticoids were most effective in controlling inflammation. Interestingly, the mineralocorticoids were also effective in reducing the inflammatory response at 5 days, suggesting that their fluid transport function helped clear disease. Thus, steroid control of middle ear disease may be useful in alleviating symptoms faster and reducing the risk to the inner ear.
MacArthur
Carol J
CJ
Department of Otolaryngology-Head & Neck Surgery and Oregon Hearing Research Center, Oregon Health & Science University, 3181 SW Sam Jackson Park Rd, Portland, OR 97239, USA. macarthc@ohsu.edu
DeGagne
Jacqueline M
JM
Kempton
J Beth
JB
Trune
Dennis R
DR
D000450:Aldosterone / Q000494:pharmacology; D000818:Animals; D003907:Dexamethasone / Q000494:pharmacology; D004195:Disease Models, Animal; D007758:Ear, Inner / Q000187:drug effects; D004432:Ear, Middle / Q000187:drug effects*; D005438:Fludrocortisone / Q000494:pharmacology; D005938:Glucocorticoids / Q000494:pharmacology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008901:Mineralocorticoids / Q000494:pharmacology*; D010033:Otitis Media / Q000188:drug therapy*; D011239:Prednisolone / Q000494:pharmacology
D005938:Glucocorticoids; D008901:Mineralocorticoids; D000450:Aldosterone; D003907:Dexamethasone; D011239:Prednisolone; D005438:Fludrocortisone