Surface‐Active Substances of the Guinea Pig Tubotympanum: A Chemical and Physical Analysis

Abstract

An attempt to describe the nature of the surface-active substances of the eustachian tube lining layer that influence normal tubal function was undertaken. Under sterile conditions, guinea pig tubotympanic washings were collected, centrifuged, and pooled. Analysis of the pooled lavages using standard surface chemistry techniques confirmed the presence of significant surface-tension-lowering activity in the mucous lining layer of the eustachian tube, but the surface pressure obtained is neither as great nor displays the same degree of hysteresis as pulmonary surfactant. Following separation into aqueous and lipid fractions, measurable amounts of surface activity can be found in both isolates. The chemical composition and concentration of the lipid fraction, and its relative contribution to the surface activity of the tubotympanic washings, however, is smaller and radically different from the phospholipids found in surfactant. A significantly higher concentration of protein was recovered in comparison with the lipid portion, and it was observed that the surface activity of the total washings and the aqueous phase bore remarkable similarities. Although the surface-tension-lowering properties of the tubal lining layer may be the consequence of a combined synergistic action of the lipid and protein moieties, we believe that the current evidence points toward the proteins as being the primary tubal surface-tension-lowering substances.

Multicenter Study on the Treatment of Secretory Otitis Media with Ambroxol

“…Our research unit has been studying na sal and tubal fluids, in agreement with the studies by Maves et al [9] showing that the antiadhesive action in these organs is due to a mixture of indispensable phospholip ids and glycoproteins which may act synergistically.…”

Effect of Body Position, Epinephrine, and a Surface-Tension-Lowering Substance on the Eustachian Tube Opening in the Rat

“…In 1963, Flisberget al [4] suggested, in a study on humans, that a surface-tension lowering substance exists, which might facili tate the opening of the ET. The existence of such substances has then been demonstrated in animals [5][6][7], Kahn et al [8] found that a substance which can reduce the viscosity of the secretion improved healing of secretory otitis media. Very recently, a study of the human ET showed that atropine reduced both the active and passive pressure-equilibrating capacity [9].…”

Surface Tension of Secretions from Eustachian Tube and Middle Ear

“…For the analysis of surface-active material in the secretions from the middle ear and the ET, biochemical and biophysical methods have been used. Lipids have been separated with chro matography [3,4,8], and surface properties have been studied with the Langmuir-Wilhelmy balance [7][8][9] and with the bubble stability method [6]. A difficulty en countered has been the limited volume of secretion that has been possible to obtain from the ET as well as from the middle ear.…”