Ultrastructural studies of the round-window membrane of the cat.

An ultrastructural study of eight round-window membranes of four normal cats disclosed three basic layers: an outer epithelium (middle ear), a middle core of connective tissue, and an inner epithelium (inner ear). Morphologic evidence suggests that these layers participate in absorption and secretion of substances to and from the inner ear, such that the entire membrane could play a role in an inner ear "defense system." A comparison of morphologic features of round-window membranes from cats, rodents, and human beings suggests that the cat is a superior animal model for experimental studies. Cationic ferritin, placed for two hours in the round-window niche of four normal cats, was observed to traverse the round-window membrane through pinocytotic vesicles into the connective tissue layer. Evidence of exocytosis of tracer by the inner epithelial layer into the scala tympani is presented. When placed in perilymph, this same tracer was incorporated by inner epithelial cells, suggesting absorptive capabilities of the round-window membrane.

[1]  P. Schlievert,et al.  Permeability of the middle ear to staphylococcal pyrogenic exotoxin in otitis media. , 1980, International journal of pediatric otorhinolaryngology.

[2]  M. Paparella,et al.  Oval and round window changes in otitis media. Potential pathways between middle and inner ear , 1980, The Laryngoscope.

[3]  M. Paparella,et al.  Fine Structure of the round Window Membrane , 1971, The Annals of otology, rhinology, and laryngology.

[4]  C. Ilberg,et al.  Qualitative Untersuchungen der Verbindungswege des Subarachnoidalraumes mit dem Lymphatischen System des Kopfes und des Halses , 1972 .

[5]  G. Palade,et al.  STUDIES ON BLOOD CAPILLARIES , 1968, The Journal of cell biology.

[6]  M. Paparella,et al.  The human round window membrane. An electron microscopic study. , 1984, Archives of otolaryngology.

[7]  T. Okuno,et al.  The round window membrane. , 1983, Advances in oto-rhino-laryngology.

[8]  G. Proud,et al.  Ototoxicity of topically applied chloramphenicol. , 1968, Archives of otolaryngology.

[9]  H. Schuknecht.  Ablation therapy in the management of Menière's disease. , 1957, Acta oto-laryngologica. Supplementum.

[10]  I. Benedeczky,et al.  The ultrastructure of the round window membrane of the cat. , 1978, ORL; journal for oto-rhino-laryngology and its related specialties.

[11]  M. Paparella,et al.  Permeability of the round window membrane in otitis media. , 1980, Archives of otolaryngology.

[12]  W. Bossert,et al.  Vesicular transport across endothelium: a generalized diffusion model. , 1973, Microvascular research.

[13]  N. Simionescu,et al.  PERMEABILITY OF MUSCLE CAPILLARIES TO EXOGENOUS MYOGLOBIN , 1973, The Journal of cell biology.

[14]  T. L. Richardson,et al.  Submicroscopic studies of the round window membrane. , 1971, Acta oto-laryngologica.

[15]  M. Oda,et al.  Pathology of Sensorineural Hearing Loss in Otitis Media , 1972, The Annals of otology, rhinology, and laryngology.

[16]  I. Benedeczky,et al.  Ultrastructural organization of the round window membrane in the infant human middle ear. , 1983, ORL; journal for oto-rhino-laryngology and its related specialties.

[17]  W. E. Rahm,et al.  LXXIII The Effects of Topical Anesthetics upon the Ear , 1959, The Annals of otology, rhinology, and laryngology.

[18]  T. Palva,et al.  Fluid pathways in temporal bones. , 1979, Acta oto-laryngologica.

[19]  G. Palade,et al.  CELL JUNCTIONS IN AMPHIBIAN SKIN , 1965, The Journal of cell biology.

[20]  Katsuhiko Tanaka,et al.  Permeability of the labyrinthine windows in guinea pigs , 1981, Archives of oto-rhino-laryngology.

[21]  S. Juhn,et al.  Cells Involved in the Middle Ear Defense System , 1980, The Annals of otology, rhinology & laryngology. Supplement.

[22]  K. Franke.  Freeze-fracture aspects of the junctional complexes in the round window membrane , 1977, Archives of oto-rhino-laryngology.

[23]  M. Paparella,et al.  The normal chinchilla round window membrane. , 1982, Archives of otolaryngology.

[24]  J. Wersäll,et al.  SITE OF ACTION OF OTOTOXIC ANTIBIOTICS AFTER LOCAL AND GENERAL ADMINISTRATION , 1970 .

[25]  E. M. Renkin,et al.  Transport of large molecules from plasma to interstitial fluid and lymph in dogs. , 1970, The American journal of physiology.

[26]  M. Paparella,et al.  Endolymphatic hydrops and otitis media , 1979, The Laryngoscope.

[27]  E. Hentzer,et al.  Surgical Treatment of Recurrent Perilymph Fistula with Anacusis , 1980, The Annals of otology, rhinology, and laryngology.

[28]  W. Arnold.  Role of Perilymph in the Early Stage of Serous Otitis , 1976, The Annals of otology, rhinology, and laryngology.

[29]  M. Myers,et al.  The Penetration of Gentamicin and Neomycin into Perilymph Across the Round Window Membrane , 1979, Otolaryngology and head and neck surgery.