In vivo demonstration of the absorptive function of the middle ear epithelium

Li, Jiping; Kania, Romain; Lecain, Éric; Ar, Amos; Sauvaget, E.; Huy, P. Tran Ba; Herman, Philippe

doi:10.1016/j.heares.2005.04.011

Cited by 21 publications

(31 citation statements)

References 26 publications

(31 reference statements)

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“…Recently, this same group has also conducted an in vivo study [Li et al, 2005] in which the rate of fluid absorption was assessed from the movement of fluid in a horizontal tube coupled to the fluids applied to the middle ear. Following application of a saline solution to the middle ear, they found an initial phase of fluid volume increase (about 2 l) lasting about 30 min.…”

Section: Discussionmentioning

confidence: 99%

“…Thus, their results do not exclude the involvement of other mechanisms, in addition to active Na removal driving an outflow of water. Finally, Li et al [2005] go on to estimate the time required to completely clear all fluid from the rat middle ear (13 h). However, this assessment is based only on the linear rate of absorption seen between 50-80 min following the application of saline.…”

Section: Discussionmentioning

confidence: 99%

“…The osmotic gradient may be initially present, such as exists with respect to the amniotic fluid in the middle ear of the neonate and apparently in the earlier stages of serous otitis media, or it may be induced at a later stage by active sodium transport, as suggested by Li et al [2005].…”

Section: Discussionmentioning

confidence: 99%

“…In both cases, normal middle ear function and hearing require the clearance of this incompressible fluid and its replacement by compressible air. Several mechanisms have been implicated in this clearance: a pumping action through the eustachian tube following contraction of the tensor veli palatini muscle [Cantekin et al, 1979;Honjo et al, 1981Honjo et al, , 1985; removal by the beating cilia of the mucosal lining (mucociliary mechanism) of the middle ear and eustachian tube [Sade, 1967;Nuutinen et al, 1983]; osmotic outflow of water from the middle ear as a consequence of osmotic pressure gradients between the middle ear fluid and blood [Priner et al, 2003]; active transport of sodium by middle ear epithelium from the middle ear fluid, driving water absorption [Herman et al, 1992;Yen et al, 1993;Li et al, 2005].…”

Section: Introductionmentioning

confidence: 99%

“…Recently, Li et al [2005] have conducted an in vivo investigation of the suggested mechanism of active sodium transport driving water absorption by manipulating the levels of sodium and chloride solutions applied to the middle ear and by blocking transport of these ions with appropriate drugs. The rate of middle ear fluid absorption was assessed by observing the movement of fluid in a horizontal tube in the external meatus which was in contact with the middle ear fluid through a perforated tympanic membrane.…”

Section: Introductionmentioning

confidence: 99%

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Mechanism and Rate of Middle Ear Fluid Absorption

Petrova

Freeman²,

Sohmer³

2007

Audiol Neurotol

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Several mechanisms have been suggested to explain the clearance of fluids from the middle ear. These include a pumping action through the eustachian tube, mucociliary beating through the tube, outflow of water to the blood due to osmotic gradients and an active Na⁺ transport driving water absorption. In order to assess these mechanisms, the middle ear cavity of paralyzed, ventilated (eustachian tube occluded) guinea pigs was filled with fluids varying in osmotic pressure (hypotonic, isotonic, hypertonic) to which a vertical tube was attached. The change in height of fluid in the tube was taken as a measure of changes in middle ear fluid volume. A greater fluid volume reduction was seen with the hypotonic (1/5 saline) solution. A small volume increase was observed with the hypertonic solution. These results provide evidence that in these experimental conditions, water absorption due to osmotic gradients can contribute to middle ear fluid clearance.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Mechanism and Rate of Middle Ear Fluid Absorption

Petrova

Freeman²,

Sohmer³

2007

Audiol Neurotol

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Steroid Control of Acute Middle Ear Inflammation in a Mouse Model

MacArthur¹,

DeGagne²,

Kempton³

et al. 2009

Archives of Otolaryngology - Head and Neck Surgery

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Objective The middle ear innate immune response to bacteria leads to acute inflammation consisting of fluid accumulation, infiltration of inflammatory cells, and mucosal thickening. Although inflammation from otitis media generally subsides after 5–7 days, suppression of this response would help alleviate suffering and minimize risk to the inner ear. 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. Therefore, steroids were investigated for their potential for therapeutic approaches to control of otitis media. Design Both glucocorticoid (prednisolone, dexamethasone) and mineralocorticoid (aldosterone, fludrocortisone) steroids were investigated for their ability to reduce inflammatory symptoms in a mouse otitis media model. Subjects Acute inflammation was induced by transtympanic injection of heat killed Streptococcus pneumoniae to 100 Balb/c mice. Interventions Twenty mice in each experimental group (prednisolone, dexamethasone, aldosterone, fludrocortisone) were given a steroid in their drinking water the day before inoculation and continued on these treatments until histologic observance. Twenty control mice were treated with water only. 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 their fluid transport function helped clear disease. Thus, steroid control of middle ear disease may be useful in alleviating symptoms faster and reducing risk to the inner ear.

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