Human Middle Ear Gas Composition Studied by Mass Spectrometry

Hergils, Leif; Magnuson, Bengt

doi:10.3109/00016489009122520

Cited by 66 publications

(61 citation statements)

References 15 publications

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“…The obstruction shut off the pathway of oxygen exchanges between the air and the cavity. The oxygen tension varies from 44 to 54 mm Hg in healthy ears [39,40] , but may be lower in the course of SOM. The influence of oxygen tension on the middle ear ion transport functions has revealed that prolonged incubation of the middle ear epithelial cells in moderate hypoxia (32 mm Hg) resulted in a reversible decrease in sodium transport.…”

Section: Discussionmentioning

confidence: 99%

Expression Pattern of Aquaporin 1 in the Middle Ear of the Guinea Pig with Secretory Otitis Media

Zhang

Liu²,

Gao³

et al. 2008

ORL

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Objective: To explore the pathological change of water homeostasis in the secretory otitis media (SOM) middle ear, we observed the expression and regulation of aquaporin 1 (AQP1) in the SOM middle ear cavity. Methods: Reverse transcriptase polymerase chain reaction (RT-PCR), Western blotting and immunohistochemical staining were used to detect AQP1 in the bullae of SOM models and normal animals. The expression patterns of AQP1 in the SOM group were compared with those in the normal animal group. Results: RT-PCR and immunoblot analyses revealed that mRNAs encoding AQP1 were expressed in the middle ear membrane of the guinea pigs of both groups; AQP1 was also detected as 28-kDa proteins in both groups. Immunohistochemical analysis showed that AQP1 was localized on capillary endothelial cells and fibroblasts in the lamina propria mucosae as well as on flat and cubical epithelial cells. Quantitative analysis of RT-PCR and Western blotting revealed that AQP1 expression was higher in the SOM group than in the control group. The cellular expression of AQP1 was somewhat altered in the SOM middle ear. Conclusions: Our study suggests that AQP1 in the middle ear cavity may play a vital role in the accumulation of the effusion. It might work on the vessel-caused hydrops in the middle ear cavity.

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Section: Discussionmentioning

confidence: 99%

Expression Pattern of Aquaporin 1 in the Middle Ear of the Guinea Pig with Secretory Otitis Media

Zhang

Liu²,

Gao³

et al. 2008

ORL

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“…The rest is a mixture of biologically active gases, carbon dioxide (seven per cent), water vapour (six per cent), and oxygen (5.5 per cent). 5 The area of the cell system is greatly enhanced by bony septa by which the volume is subdivided into a large number of small cavities. The bony septa are lined by a thin one-layered cubical respiratory epithelium that for the most part lacks cilia and goblet cells.…”

Section: Introductionmentioning

confidence: 99%

Functions of the mastoid cell system: auto-regulation of temperature and gas pressure

Magnuson

2003

J. Laryngol. Otol.

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This article presents a new approach to understanding the physiological functions of the mastoid cell system. It is suggested that the cell system, in combination with the continuous blood ow through the adjacent large vessels, makes up a compound functional unit that serves to protect the sensitive vestibular part of the inner ear from inadequate stimulation by external temperature changes. By virtue of the large surface area of the cell system mucosa with respect to the enclosed gas volume, the mastoid cell system may also work as a pressure regulator. Variations of the bi-directional exchange of uid over the capillary network in the mucosa will change the size of the lumen that is available for the gas in the cell system. Volumes of gas and uid can thus be exchanged to keep the intratympanic pressure within physiological limits. The process is most effective in a cell system with a high area-to-volume ratio.

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“…The rate of exchange of these gases between the ME and blood determines the net volume of transmucosal gas exchange. For N 2 , a difference in ME to blood partial pressure of up to ϳ50 Torr has been reported, whereas that of O 2 and CO 2 is nearly zero (16,26,33). Therefore, the net volume gas loss that we have observed in the steady state (30) should result mainly from transmucosal N 2 exchange.…”

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confidence: 80%

Role of nitrogen in transmucosal gas exchange rate in the rat middle ear

Kania¹,

Herman²,

Huy³

et al. 2006

Journal of Applied Physiology

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. Role of nitrogen in transmucosal gas exchange rate in the rat middle ear. J Appl Physiol 101: [1281][1282][1283][1284][1285][1286][1287] 2006. First published July 13, 2006; doi:10.1152/japplphysiol.00113.2006.-This study investigates the role of nitrogen (N 2) in transmucosal gas exchange of the middle ear (ME). We used an experimental rat model to measure gas volume variations in the ME cavity at constant pressure. We disturbed the steady-state gas composition with either air or N 2 to measure resulting changes in volume at ambient pressure. Changes in gas volume over time could be characterized by three phases: a primary transient increase with time (phase I), followed by a linear decrease (phase II), and then a gradual decrease (phase III). The mean slope of phase II was Ϫ0.128 l/min (SD 0.023) in the air group (n ϭ 10) and Ϫ0.105 l/min (SD 0.032) in the N 2 group (n ϭ 10), but the difference was not significant (P ϭ 0.13), which suggests that the rate of gas loss can be attributed mainly to the same steady-state partial pressure gradient of N 2 reached in this phase. Furthermore, a mathematical model was developed analyzing the transmucosal N2 exchange in phase II. The model takes gas diffusion into account, predicting that, in the absence of change in mucosal blood flow rate, gas volume in the ME should show a linear decrease with time after steady-state conditions and gas composition are established. In accordance with the experimental results, the mathematical model also suggested that transmucosal gas absorption of the rat ME during steady-state conditions is governed mainly by diffusive N2 exchange between the ME gas and its mucosal blood circulation. rat model

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Human Middle Ear Gas Composition Studied by Mass Spectrometry

Cited by 66 publications

References 15 publications

Expression Pattern of Aquaporin 1 in the Middle Ear of the Guinea Pig with Secretory Otitis Media

Expression Pattern of Aquaporin 1 in the Middle Ear of the Guinea Pig with Secretory Otitis Media

Functions of the mastoid cell system: auto-regulation of temperature and gas pressure

Role of nitrogen in transmucosal gas exchange rate in the rat middle ear

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