title: Facilitated transfer of glucose from blood into perilymph in the rat cochlea.
abstract: The transport of glucose into cochlear endolymph, perilymph of scala vestibuli and perilymph of scala tympani, and cerebrospinal fluid (CSF) was studied after intravenous administration of tracers of D-glucose, L-glucose, and 3-O-methyl-D-glucose in anesthetized rats. The data showed that D-glucose concentrations in perilymph of scala vestibuli, perilymph of scala tympani, and CSF were approximately 50%, and in endolymph less than 10%, that in plasma; D-glucose concentration in perilymph of scala vestibuli, perilymph of scala tympani, and CSF increased as a linear function of that in plasma; D-glucose entry into perilymph of scala vestibuli, perilymph of scala tympani, and CSF was more rapid than that of L-glucose; after infusion of 3-O-methyl-D-glucose, but not after that of mannitol, both the D-glucose concentration ratio of perilymph over plasma and D-glucose transfer into perilymph were lowered. These results indicate that D-glucose enters into perilymph of scala vestibuli by a facilitated transport, possibly located at the blood-perilymph barrier.
mesh_terms: D019325:3-O-Methylglucose; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism*; D003051:Cochlea / Q000378:metabolism*; D005947:Glucose / Q000134:cerebrospinal fluid / Q000378:metabolism; D007700:Kinetics; D007761:Labyrinthine Fluids / Q000378:metabolism*; D008297:Male; D008353:Mannitol / Q000494:pharmacology; D008757:Methylglucosides / Q000494:pharmacology; D009994:Osmolar Concentration; D010498:Perilymph / Q000378:metabolism*; D010693:Phloretin / Q000494:pharmacology; D010695:Phlorhizin / Q000494:pharmacology; D011188:Potassium / Q000097:blood / Q000134:cerebrospinal fluid / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D012964:Sodium / Q000097:blood / Q000134:cerebrospinal fluid / Q000378:metabolism
chemical_list: D001786:Blood Glucose; D008757:Methylglucosides; D019325:3-O-Methylglucose; D008353:Mannitol; D012964:Sodium; D010695:Phlorhizin; D005947:Glucose; D011188:Potassium; D010693:Phloretin