Biomaterial Database

Effect of urea on osmolality of perilymph. 1979

S K Juhn, and S Prado, and L Rybak

Blood osmolality was altered in chinchillas by intravenous administration of urea. Serum osmolality peaked rapidly at 30 minutes after administration and decreased slightly to a plateau for 180 minutes. Perilymph and CSF osmolality lagged substantially behind the increase in serum osmolality and equaled serum osmolality only after one hour. Perilymph osmolality followed changes in the serum up to 60 minutes with a definite time lag. This phenomenon suggests the existence of a selective blood-labyrinth barrier that is permeable to urea and water. However, the time lag due to the barrier may permit the reduction of hydrostatic pressure in the labyrinth. The results of the present study seem to render partial explanation of improved hearing in patients with Meniere's disease who were treated with urea.

UI	MeSH Term	Description	Entries
D007761	Labyrinthine Fluids	Fluids found within the osseous labyrinth (PERILYMPH) and the membranous labyrinth (ENDOLYMPH) of the inner ear. (From Gray's Anatomy, 30th American ed, p1328, 1332)	Fluid, Labyrinthine,Fluids, Labyrinthine,Labyrinthine Fluid
D009994	Osmolar Concentration	The concentration of osmotically active particles in solution expressed in terms of osmoles of solute per liter of solution. Osmolality is expressed in terms of osmoles of solute per kilogram of solvent.	Ionic Strength,Osmolality,Osmolarity,Concentration, Osmolar,Concentrations, Osmolar,Ionic Strengths,Osmolalities,Osmolar Concentrations,Osmolarities,Strength, Ionic,Strengths, Ionic
D010498	Perilymph	The fluid separating the membranous labyrinth from the osseous labyrinth of the ear. It is entirely separate from the ENDOLYMPH which is contained in the membranous labyrinth. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed, p1396, 642)	Perilymphs
D001769	Blood	The body fluid that circulates in the vascular system (BLOOD VESSELS). Whole blood includes PLASMA and BLOOD CELLS.
D002555	Cerebrospinal Fluid	A watery fluid that is continuously produced in the CHOROID PLEXUS and circulates around the surface of the BRAIN; SPINAL CORD; and in the CEREBRAL VENTRICLES.	Cerebro Spinal Fluid,Cerebro Spinal Fluids,Cerebrospinal Fluids,Fluid, Cerebro Spinal,Fluid, Cerebrospinal,Fluids, Cerebro Spinal,Fluids, Cerebrospinal,Spinal Fluid, Cerebro,Spinal Fluids, Cerebro
D002682	Chinchilla	A genus of the family Chinchillidae which consists of three species: C. brevicaudata, C. lanigera, and C. villidera. They are used extensively in biomedical research.	Chinchillas
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
D014508	Urea	A compound formed in the liver from ammonia produced by the deamination of amino acids. It is the principal end product of protein catabolism and constitutes about one half of the total urinary solids.	Basodexan,Carbamide,Carmol