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

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.

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

AJP Renal Physiology ◽

10.1152/ajprenal.1989.257.3.f341 ◽

1989 ◽

Vol 257 (3) ◽

pp. F341-F346 ◽

Cited By ~ 3

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)

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

Archives of Oto-Rhino-Laryngology ◽

10.1007/bf00463614 ◽

1983 ◽

Vol 237 (2) ◽

pp. 147-152 ◽

Cited By ~ 17

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

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Efferent-mediated protection from acoustic overexposure: relation to slow effects of olivocochlear stimulation

Journal of Neurophysiology ◽

10.1152/jn.1995.73.2.506 ◽

1995 ◽

Vol 73 (2) ◽

pp. 506-514 ◽

Cited By ~ 102

Author(s):

E. R. Reiter ◽

M. C. Liberman

Keyword(s):

Electrical Stimulation ◽

Inner Ear ◽

Guinea Pigs ◽

Threshold Shift ◽

Exposure Condition ◽

Protective Effects ◽

Acoustic Overstimulation ◽

Different Levels ◽

Stimulation Of

1. The present study attempts to resolve discrepancies in the reported role of olivocochlear (OC) efferent activation in protecting the inner ear from acoustic overstimulation: in previous studies, activating the OC system in guinea pigs reduced the threshold shift caused by 1 min monaural exposure to a 10-kHz tone; whereas unilateral OC activation in cats had no effect on threshold shifts following binaural exposure to a 10 min 6-kHz tone. 2. In this study, anesthetized and curarized guinea pigs were exposed either monaurally or binaurally to tones of different duration (1-5 min), frequency (6 to 10 kHz) and intensity (105-118 dB SPL). For each exposure condition, threshold shifts were compared among ears with different levels of OC activation: in some cases, the OC bundle (OCB) was electrically stimulated during (and/or before) the acoustic overexposure; in others, the OCB was cut before the exposure; in control cases, the OCB was neither cut nor electrically stimulated. 3. Electrical stimulation of the OCB delivered simultaneously with acoustic overstimulation produced significant reductions in threshold shift only for acoustic exposures at higher frequencies (8 and 10 kHz) and shorter durations (1 and 2 min). The protective effects on 1-min exposures could be extinguished by prior stimulation of the OCB, i.e., if the OC stimulation was turned on 4 min before the acoustic overexposure.(ABSTRACT TRUNCATED AT 250 WORDS)

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Effects of Repeated Changes in Atmospheric Pressure on Inner Ear of Guinea Pigs

Auris Nasus Larynx ◽

10.1016/s0385-8146(12)80148-9 ◽

1992 ◽

Vol 19 ◽

pp. S13-S24

Author(s):

Yuri Yamamuro ◽

Tsutomu Nakashima ◽

Noriyuki Yanagita

Keyword(s):

Inner Ear ◽

Atmospheric Pressure ◽

Guinea Pigs

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Audiological Study in Guinea Pigs with Type I Allergy Induced in the Inner Ear

Annals of Otology Rhinology & Laryngology ◽

10.1177/000348949310200709 ◽

1993 ◽

Vol 102 (7) ◽

pp. 537-542 ◽

Cited By ~ 3

Author(s):

Kengo Uno ◽

Hironori Fukuda ◽

Kenichiro Miyamura ◽

Keisuke Masuyama ◽

Yorinori Kanzaki ◽

...

Keyword(s):

Brain Stem ◽

Inner Ear ◽

Guinea Pigs ◽

Type I ◽

Auditory Brain Stem Response ◽

Type I Allergy ◽

Summating Potential ◽

Auditory Brain Stem ◽

Brain Stem Response ◽

Specific Challenge

Time course studies of electrocochleography and the auditory brain stem response were performed in guinea pigs that were passively sensitized by sera containing antidinitrophenyl reaginic antibody and specifically challenged by dinitrophenyl—bovine serum albumin injected through the stylomastoid foramen. A negative summating potential on electrocochleography was observed from 12 to 48 hours, but not at 72 hours, after the specific challenge. A threshold increase on the auditory brain stem response was observed 15 minutes after the specific challenge; the threshold recovered to the prechallenge level within 7 days. Further, we used Tranilast, a blocking agent of chemical mediator release from mast cells, before the specific challenge. A negative summating potential and head deviation were not observed after the use of this agent. These results suggest that the auditory change provoked in the inner ear of the sensitized guinea pig may have been induced by type I allergy.

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Effects of acute lead acetate exposure on adult guinea pigs: Electrophysiological study of the inner ear

Fundamental and Applied Toxicology ◽

10.1016/0272-0590(89)90287-x ◽

1989 ◽

Vol 13 (3) ◽

pp. 509-515 ◽

Cited By ~ 30

Author(s):

K YAMAMURA

Keyword(s):

Inner Ear ◽

Guinea Pigs ◽

Lead Acetate ◽

Electrophysiological Study

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The olivocochlear efferent bundle and susceptibility of the inner ear to acoustic injury

Journal of Neurophysiology ◽

10.1152/jn.1991.65.1.123 ◽

1991 ◽

Vol 65 (1) ◽

pp. 123-132 ◽

Cited By ~ 53

Author(s):

M. C. Liberman

Keyword(s):

Inner Ear ◽

Guinea Pigs ◽

Compound Action Potential ◽

Feedback System ◽

Acoustic Stimulation ◽

Experimental Series ◽

Threshold Shift ◽

Cochlear Blood Flow ◽

Auditory Periphery ◽

Control Measurement

1. The role of the efferent olivocochlear bundle (OCB) in protecting the inner ear from acoustic injury was studied in the anesthetized cat. Middle-ear muscles (MEM) were cut to eliminate possible effects of this feedback system on the auditory periphery. In each of a series of animals, the OCB was unilaterally transected. The animal was then exposed binaurally to an intense pure tone, and the resultant damage to the two sides compared by measuring threshold shifts in the compound action potential from each ear. Data from each animal provide one control measurement (threshold shift with an intact OCB) and one experimental measurement (threshold shift without a functional OCB). 2. Two experimental series were analyzed. In one the OCB was electrically stimulated, providing maximal firing rates in the efferents projecting to the control ear. In another series the OCB was not electrically stimulated: thus any OCB activity to the control ear was only that evoked by the acoustic stimulation itself. 3. In neither experimental series was there evidence that activity in the OCB provides protection from acoustic injury. These results are in disagreement with conclusions drawn from experiments with acoustic overstimulation of guinea pigs. 4. Interpretations for the discrepancy between the present study and those on guinea pigs include interspecies differences and the possible contribution of the MEM reflex or cochlear blood-flow changes to previously observed effects.

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