Effect of glycerol on electrochemical composition of endolymph and perilymph in the rat.
Glycerol (2 g/kg body weight), or 0.15 M NaCl for control animals, was administered to rats by i.v. injection. The dose was chosen in order to obtain an osmolarity increase in plasma of about 15 mosm/l 1 h after the glycerol administration, an increase which is similar to that observed in the human glycerol dehydration test. Endolymph and perilymph were sampled from the basal turn of the cochlea; cerebrospinal fluid (CSF) was sampled from cisterna magna. Plasma osmolarity, endocochlear potential, Na and K concentrations in endolymph, perilymph and CSF were determined 1 and 2 h after the glycerol injection. Compared with control animals, glycerol induced an increase in Na and K concentration in perilymph and endolymph, respectively, 1 and 2 h after the glycerol injection. No modification of the endocochlear potential was observed. These results are compatible with an increase in inner ear fluids osmolarity induced by glycerol.
Morrison
G A
GA
INSERM U.251, Faculté Xavier Bichat, Université Paris 7, France.
Teixeira
M
M
Sterkers
O
O
Amiel
C
C
Ferrary
E
E
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D001769:Blood; D003051:Cochlea / Q000187:drug effects / Q000502:physiology; D004234:Diuretics, Osmotic / Q000008:administration & dosage / Q000494:pharmacology; D004563:Electrochemistry; D004710:Endolymph / Q000737:chemistry* / Q000187:drug effects; D005500:Follow-Up Studies; D005990:Glycerol / Q000008:administration & dosage / Q000494:pharmacology*; D006801:Humans; D007275:Injections, Intravenous; D009994:Osmolar Concentration; D010498:Perilymph / Q000737:chemistry* / Q000187:drug effects; D011188:Potassium / Q000032:analysis / Q000134:cerebrospinal fluid; D051381:Rats; D012964:Sodium / Q000032:analysis / Q000134:cerebrospinal fluid
D004234:Diuretics, Osmotic; D012964:Sodium; D005990:Glycerol; D011188:Potassium