title: Relationship between the gas composition of the middle ear and the venous blood at steady state.
abstract: Concomitant continuous measurements of the steady-state gas composition of the middle ear and of the venous blood were recorded by mass spectrometry in four guinea pigs. The following mean values were obtained for the partial pressures of middle ear gases; nitrogen + argon, 606.4 mm Hg; oxygen, 46.2 mm Hg; and carbon dioxide, 60.2 mm Hg. The corresponding values for the venous blood were as follows: Nitrogen + argon, 563.4 mm Hg; oxygen, 38.0 mm Hg; and carbon dioxide, 61.4 mm Hg. The similarity of the steady-state gas composition of the middle ear to that of the venous blood suggests that the partial pressures of the gases in the middle ear are controlled by interchange with gases present in the blood.
authors.affiliation: Sarita and Felix Chair for Hearing Research, Ear Research Laboratory, Sackler School of Medicine and Bioengineering Program, Tel-Aviv University, Israel.
authors.forename: M
authors.initials: M
authors.lastname: Luntz
authors.forename: D
authors.initials: D
authors.lastname: Levi
authors.forename: J
authors.initials: J
authors.lastname: Sadé
authors.forename: M
authors.initials: M
authors.lastname: Herman
mesh_terms: D000818:Animals; D001128:Argon / Q000032:analysis; D002245:Carbon Dioxide / Q000032:analysis; D004432:Ear, Middle / Q000737:chemistry*; D005260:Female; D005740:Gases / Q000032:analysis*; D006168:Guinea Pigs; D013058:Mass Spectrometry / Q000379:methods; D009584:Nitrogen / Q000032:analysis; D009862:Online Systems; D010100:Oxygen / Q000032:analysis; D010313:Partial Pressure
chemical_list: D005740:Gases; D002245:Carbon Dioxide; D001128:Argon; D009584:Nitrogen; D010100:Oxygen