Biomaterial Database

Round window membrane permeability to transforming growth factor-alpha: an in vitro study. 2000

M C Witte, and J L Kasperbauer

Department of Otorhinolaryngology, Mayo Clinic and Mayo Foundation, Rochester, MN 55905, USA.

OBJECTIVE Recent studies have identified the capacity of transforming growth factor-alpha (TGF-alpha) to stimulate mammalian labyrinthine hair cell regeneration after acute ototoxic damage. Augmenting hair cell regeneration with such growth factors may have a role in potentiation of recovery of cochlear function after hair cell injury. Transtympanic application of aqueous solutions to the round window membrane (RWM) has proved successful as a drug delivery route. The purpose of this study was to test the permeability of the mammalian RWM to TGF-alpha in an inexpensive and reliable in vitro model. METHODS Guinea pig RWM niches were harvested and transferred to a 2-chamber apparatus, and TGF-alpha was applied to the middle-ear side of the chamber. ELISAs of TGF-alpha were measured at intervals during a 96-hour period. RESULTS Aliquots taken during a 96-hour interval demonstrated passage of TGF-alpha in concentrations sufficient to stimulate hair cell regrowth. CONCLUSIONS The apparatus allows study of RWM permeability to other substances and provides a basic model for study of RWM physiology. TGF-alpha is able to pass through a mammalian RWM.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D002463	Cell Membrane Permeability	A quality of cell membranes which permits the passage of solvents and solutes into and out of cells.	Permeability, Cell Membrane
D004797	Enzyme-Linked Immunosorbent Assay	An immunoassay utilizing an antibody labeled with an enzyme marker such as horseradish peroxidase. While either the enzyme or the antibody is bound to an immunosorbent substrate, they both retain their biologic activity; the change in enzyme activity as a result of the enzyme-antibody-antigen reaction is proportional to the concentration of the antigen and can be measured spectrophotometrically or with the naked eye. Many variations of the method have been developed.	ELISA,Assay, Enzyme-Linked Immunosorbent,Assays, Enzyme-Linked Immunosorbent,Enzyme Linked Immunosorbent Assay,Enzyme-Linked Immunosorbent Assays,Immunosorbent Assay, Enzyme-Linked,Immunosorbent Assays, Enzyme-Linked
D006168	Guinea Pigs	A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research.	Cavia,Cavia porcellus,Guinea Pig,Pig, Guinea,Pigs, Guinea
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D012405	Round Window, Ear	Fenestra of the cochlea, an opening in the basal wall between the MIDDLE EAR and the INNER EAR, leading to the cochlea. It is closed by a secondary tympanic membrane.	Cochlear Round Window,Fenestra Cochleae,Round Window of Ear,Cochlear Round Windows,Ear Round Window,Round Window, Cochlear,Round Windows, Cochlear,Round Windows, Ear
D016211	Transforming Growth Factor alpha	An EPIDERMAL GROWTH FACTOR related protein that is found in a variety of tissues including EPITHELIUM, and maternal DECIDUA. It is synthesized as a transmembrane protein which can be cleaved to release a soluble active form which binds to the EGF RECEPTOR.	Epidermal Growth Factor-Related Transforming Growth Factor,TGF-alpha,TGFalpha,Epidermal Growth Factor Related Transforming Growth Factor
D066298	In Vitro Techniques	Methods to study reactions or processes taking place in an artificial environment outside the living organism.	In Vitro Test,In Vitro Testing,In Vitro Tests,In Vitro as Topic,In Vitro,In Vitro Technique,In Vitro Testings,Technique, In Vitro,Techniques, In Vitro,Test, In Vitro,Testing, In Vitro,Testings, In Vitro,Tests, In Vitro,Vitro Testing, In