Prenatal maturation of endocochlear potential and electrolyte composition of inner ear fluids in guinea pigs

1983 ◽  
Vol 237 (2) ◽  
pp. 147-152 ◽  
Author(s):  
Yehoash Raphael ◽  
Masaki Ohmura ◽  
Naoyuki Kanoh ◽  
Nobuya Yagi ◽  
Kazuo Makimoto
Keyword(s):  
Inner Ear ◽  
Guinea Pigs ◽  
Endocochlear Potential ◽  
Electrolyte Composition ◽  
Inner Ear Fluids

Electrochemical heterogeneity of the cochlear endolymph: effect of acetazolamide

1984 ◽  
Vol 246 (1) ◽  
pp. F47-F53 ◽  
Author(s):  
O. Sterkers ◽  
G. Saumon ◽  
P. Tran Ba Huy ◽  
E. Ferrary ◽  
C. Amiel
Keyword(s):  
Inner Ear ◽  
Endocochlear Potential ◽  
Electrochemical Gradient ◽  
Acid Base ◽  
Basal Turn ◽  
Ph Values ◽  
Blood Ph ◽  
Acid Base Status ◽  
Electrochemical Heterogeneity ◽  
Inner Ear Fluids

The electrochemical composition of endolymph (EL) of two adjacent cochlear turns was studied in anesthetized rats. Differences in [K]EL, [Cl]EL, and endocochlear potential (EP) were found between the basal turn (165.6 +/- 3.0 mM, n = 14; 144.6 +/- 2.1 mM, n = 14;96.6 +/- 1.9 mV, n = 5, respectively) and the middle turn (155.7 +/- 2.5 mM, n = 15; 133.2 +/- 1.5 mM, n = 15; 87.0 +/- 1.6 mV, n = 6, respectively). The pH values of inner ear fluids were evaluated with 5,5-dimethyloxazolidine-2,4-dione: EL pH of either turn was not different from blood and perilymph (PL) pH. Acetazolamide (40 mg X kg body wt-1) reduced EP and [Cl]EL at each turn by about 20 and 6%, respectively, but [K]EL was unchanged. The electrochemical differences between the two turns persisted. Acetazolamide produced a 0.2-unit decrease in blood pH while the pH values of EL and PL remained unchanged. These results suggest the existence of an electrochemical gradient within EL from the base to the apex of the cochlea involving K+ and Cl- concentrations. H+ and HCO-3 do not appear to participate in this gradient, and the acid-base status in EL could be maintained both by active H+ transport into EL and by HCO-3 formation in the cochlear epithelium.

scholarly journals COLLECTION OF INNER EAR FLUIDS IN GUINEA PIGS AND THEIR UTILIZATION

1986 ◽  
Vol 11 (4) ◽  
pp. 414-417
Author(s):  
Hiroshi MORIOKA ◽  
Takayoshi KOBAYASHI
Keyword(s):  
Inner Ear ◽  
Guinea Pigs ◽  
Inner Ear Fluids

The Developing Electrolytes Concentrations of Inner Ear Fluids in Guinea Pigs

1985 ◽  
Vol 99 (5-6) ◽  
pp. 525-528 ◽  
Author(s):  
Naoyuki Kanoh ◽  
Masaki Ohmura ◽  
Tatuya Fukazawa ◽  
Yoshinobu Hirono ◽  
Kazuo Makimoto
Keyword(s):  
Inner Ear ◽  
Guinea Pigs ◽  
Inner Ear Fluids

Immunology of the inner ear: Response of the inner ear to antigen challenge

1983 ◽  
Vol 91 (1) ◽  
pp. 18-23 ◽  
Author(s):  
Jeffrey P. Harris
Keyword(s):  
Inner Ear ◽  
Blood Brain Barrier ◽  
Guinea Pigs ◽  
Keyhole Limpet Hemocyanin ◽  
Host Immunity ◽  
Brain Barrier ◽  
Antigen Challenge ◽  
Antibody Titers ◽  
Relationship Of ◽  
The Relationship

The relationship of the inner ear to host immunity and the immunoresponsiveness of the inner ear to antigen challenge were investigated. A radioimmunoassay was used to quantitate antibody titers to keyhole-limpet hemocyanin generated in the serum, perilymph, and CSF of guinea pigs following systemic or inner ear immunizations. The results of these experiments demonstrate (1) the blood-labyrinth barrier is analogous to the blood-brain barrier with respect to immunoglobulin equilibrium, (2) the inner ear is capable of responding to antigen challenge, and (3) the inner ear is an effective route for systemic immunization.

X-ray microanalysis of inner ear fluids in the embryonic and newborn guinea pig

1982 ◽  
Vol 234 (2) ◽  
pp. 125-130 ◽  
Author(s):  
Matti Anniko ◽  
Aron Sobin ◽  
Romuald Wr�blewski
Keyword(s):  
Guinea Pig ◽  
Inner Ear ◽  
X Ray ◽  
Inner Ear Fluids

Volume receptors in guinea pig labyrinth: relevance with respect to ADH and Na control

1989 ◽  
Vol 257 (3) ◽  
pp. F341-F346 ◽  
Author(s):  
E. Bartoli ◽  
A. Satta ◽  
F. Melis ◽  
M. A. Caria ◽  
W. Masala ◽  
...  
Keyword(s):  
Inner Ear ◽  
Guinea Pigs ◽  
Control Mechanism ◽  
Extracellular Fluid ◽  
Urine Osmolality ◽  
Neural Pathways ◽  
Group Of Seven ◽  
Before And After ◽  
Pressure Changes ◽  
Inner Ear Pressure

We tested the hypothesis that changes in extracellular fluid volume are reflected by pressure changes within structures of the inner ear and that through neural pathways, a control mechanism exerts an influence on antidiuretic hormone (ADH) release and Na excretion. The study was performed on 35 guinea pigs. In protocol 1, 13 animals were studied before and after decompression of the inner ear by bilateral fluid withdrawal in an experimental setting of sustained isotonic expansion that kept the osmoreceptor partially activated and the intrathoracic volume receptors suppressed. A group of six sham-operated animals served as control. In protocol 2, nine animals were studied before and after a unilateral rise in their inner ear pressure during slightly hypertonic low-rate infusions that kept the osmoreceptor and thoracic volume receptors stimulated. A group of seven sham-operated guinea pigs served as controls. Decompression of the inner ear was attended by a rise in plasma ADH from 11.9 +/- 2.4 to 29.1 +/- 6.9 pg/ml, in urine osmolality (Uosmol) from 470 +/- 48 to 712 +/- 46 mosmol/kg (P less than 0.001), and a fall in urine flow rate (V) from 184 +/- 47 to 71 +/- 11 microliters/min (P less than 0.01), whereas plasma Na (PNa) and osmolality (Posmol) did not change. During inner ear hypertension, plasma ADH fell from 25.6 +/- 3.9 to 18.4 +/- 3.1, Uosmol from 829 +/- 58 to 627 +/- 43 (P less than 0.001), and V rose from 51 +/- 11 to 130 +/- 23 (P less than 0.001), whereas glomerular filtration rate, PNa, and Posmol did not change.(ABSTRACT TRUNCATED AT 250 WORDS)

Na and nonelectrolyte entry into inner ear fluids of the rat

1987 ◽  
Vol 253 (1) ◽  
pp. F50-F58 ◽  
Author(s):  
O. Sterkers ◽  
E. Ferrary ◽  
G. Saumon ◽  
C. Amiel
Keyword(s):  
Cerebrospinal Fluid ◽  
Inner Ear ◽  
Lateral Ventricle ◽  
Endothelial Barrier ◽  
Scala Tympani ◽  
Epithelial Secretion ◽  
Kinetics Of ◽  
Hydrophilic Solutes ◽  
Inner Ear Fluids ◽  
Scala Vestibuli

Kinetics of hydrophilic solute entry into endolymph (EL), perilymph (PL), and cerebrospinal fluid (CSF) were studied after intravenous administration (sodium, urea, glycerol, mannitol, sucrose) and cerebral lateral ventricle injection (urea, sucrose) of tracers in anesthetized rats. Samples of cochlear EL, PL of scala vestibuli (PLV), PL of scala tympani (PLT), and cisternal CSF were obtained. The data showed slow entry of tracers in PLV, PLT, and CSF as follows: Na greater than urea greater than mannitol approximately sucrose; slower entry of mannitol and sucrose in PLT and CSF than in PLV; 1 h delayed peak of radioactivity in PLV compared with the immediate peaks in PLT and CSF after CSF injection, and the value of PLV peak was 13% that in CSF; extremely slow entry of nonelectrolytes in EL. These results indicate that PLV originates mainly from plasma across a blood-perilymph barrier that restricts the entry of small hydrophilic solutes. The blood-perilymph barrier is most likely composed of an endothelial barrier associated with an epithelial secretion. The latter could be located at the vasculo-epithelial zone of the spiral limbus.

Effect of Glycerol on Inner Ear Fluid Electrolytes and Osmolalities in Guinea Pigs

1987 ◽  
Vol 96 (4) ◽  
pp. 461-467 ◽  
Author(s):  
Hiromi Ueda ◽  
Yukio Muratsuka ◽  
Teruzo Konishi
Keyword(s):  
Inner Ear ◽  
Guinea Pigs
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