Gas Permeability of Round Window Membrane

Abstract

The perilymphatic oxygen tension in the scala tympani was measured with a polarographic technique after various gases were insufflated into the middle ear cavity of 7 guinea pigs. Pure oxygen, insufflated into the middle ear cavity, easily permeated the round window membrane and elevated the perilymphatic oxygen tension. Oxygen transport to the inner ear, other than by the inner ear vessels, was confirmed. The inner ear function may partially be maintained by oxygenation through this route.

Use of the biodegradable polymer chitosan as a vehicle for applying drugs to the inner ear

“…The passages of different substances through the RWM in experimental animals have proven that the RWM behaves like a semi-permeable membrane. Extensive studies on RWM in guinea pigs [36,45,66,67] chinchillas [49,55,68,69], rhesus monkeys and cats [55,64] and mongolian gerbils [70] have revealed that the RWM is permeable to water [49] antibiotics; especially aminoglycosides, streptomycin, gentamicin and neomycin [49,71], chloramphenicol [72], tetracycline [49], antiseptics, arachidonic acid metabolites [73], bacterial endotoxins and exotoxins [41,[74][75][76][77], albumin [49,78,79], tracers such as horseradish peroxidase, latex spheres (1-µm), and cationic ferritin [44,64,67], local anesthetics [45], glucocorticoids, antioxidants [64] and gases such as oxygen [80]. Based on the animals studies, a number of factors have been described that may affect the permeability and the passage of substances through the RWM [41,44,45,55,59,81].…”

Acute effects of ambient air pollution on daily neurology clinic visits for vertigo: a time-series study in Wuhan, China

“…As we know, NO 2 is asphyxiating odorous gas characterized as one of environmental irritants. Studies showed that airborne NO 2 could penetrate into the inner ear through the round window membrane (Aguilera et al, 2013;Sasa et al, 1989) and then dissolved in the perilymph and endolymph, which resulting in the elevated peri-lymphatic and endolymphatic acidity (Mun et al, 2021). It is reported that acidic surrounding environment facilitated the degeneration of otoconia, leading to the detachement of otoconia (Walther et al, 2014).…”

Advances in research on labyrinth membranous barriers

“…Leukotrienes (LTs) such as LTC4/LTB4 can penetrate RWM, leading to dilation of capillaries ( Park and Moon, 2014 , Matsubara et al., 2014 ). Sasa et al. (1989) found that pure oxygen, insufflated into the middle ear cavity, easily permeated the round window membrane and elevated perilymphatic oxygen tension by 319%.…”