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[Simultaneous determinations of oxygen partial pressure in the scala tympani, electrocochleography and blood pressure measurements in noise stress in guinea pigs].
HNO. 1988 Sep; 36(9):367-72.HNO

Abstract

In 14 guinea pigs the pO2 in the perilymph of the scala tympani fell to 50%-80% of the original value during exposure to noise consisting of 4,000 Hz clicks with a repetition rate of 20/s, 100 dB CHL = 120 dB SPL p.e., repeated twice over a period of 24 minutes each time. For the measurements of the pO2 we used the thin 0.5 micron micro-coaxial needle electrode described by Baumgärtl and Luebbers, which was placed through the round-window membrane in the scala tympani to a depth of 600 micron. The simultaneously recorded CAP latency times were prolonged by 0.8 ms at a test loudness of 60 and 80 dB CHL. The amplitudes of the CM had declined by 60%-70% of the original values at a test loudness of 80 dB SPL p.e. The intra-arterial blood pressure in the common carotid artery of all animals remained constant. As the cortilymph spaces communicate with the perilymph of the scala tympani, our measured decline of pO2 in the perilymph could indicate a cortilymph hypoxia. During exposure to noise the oxygen-dependent Na+ and K+ pumps, which maintain the ion balance and function of the organ of Corti, can decompensate due to lack of oxygen. That would lead to a K+ contamination of the cortilymph and to an intracellular Na+ accumulation, which can cause microstructural damage (hair cell-cilia fusion, hair cell, synaptic and dendritic swelling, hair cell contraction and sustained depolarization), which would be reflected in the CMs and CAPs.

Authors+Show Affiliations

Abteilung Experimentelle Otologie, HNO-Klinik der Medizinischen Hochschule Hannover.No affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

English Abstract
Journal Article

Language

ger

PubMed ID

3170282

Citation

Lamm, K, et al. "[Simultaneous Determinations of Oxygen Partial Pressure in the Scala Tympani, Electrocochleography and Blood Pressure Measurements in Noise Stress in Guinea Pigs]." HNO, vol. 36, no. 9, 1988, pp. 367-72.
Lamm K, Lamm C, Lamm H, et al. [Simultaneous determinations of oxygen partial pressure in the scala tympani, electrocochleography and blood pressure measurements in noise stress in guinea pigs]. HNO. 1988;36(9):367-72.
Lamm, K., Lamm, C., Lamm, H., & Schumann, K. (1988). [Simultaneous determinations of oxygen partial pressure in the scala tympani, electrocochleography and blood pressure measurements in noise stress in guinea pigs]. HNO, 36(9), 367-72.
Lamm K, et al. [Simultaneous Determinations of Oxygen Partial Pressure in the Scala Tympani, Electrocochleography and Blood Pressure Measurements in Noise Stress in Guinea Pigs]. HNO. 1988;36(9):367-72. PubMed PMID: 3170282.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - [Simultaneous determinations of oxygen partial pressure in the scala tympani, electrocochleography and blood pressure measurements in noise stress in guinea pigs]. AU - Lamm,K, AU - Lamm,C, AU - Lamm,H, AU - Schumann,K, PY - 1988/9/1/pubmed PY - 1988/9/1/medline PY - 1988/9/1/entrez SP - 367 EP - 72 JF - HNO JO - HNO VL - 36 IS - 9 N2 - In 14 guinea pigs the pO2 in the perilymph of the scala tympani fell to 50%-80% of the original value during exposure to noise consisting of 4,000 Hz clicks with a repetition rate of 20/s, 100 dB CHL = 120 dB SPL p.e., repeated twice over a period of 24 minutes each time. For the measurements of the pO2 we used the thin 0.5 micron micro-coaxial needle electrode described by Baumgärtl and Luebbers, which was placed through the round-window membrane in the scala tympani to a depth of 600 micron. The simultaneously recorded CAP latency times were prolonged by 0.8 ms at a test loudness of 60 and 80 dB CHL. The amplitudes of the CM had declined by 60%-70% of the original values at a test loudness of 80 dB SPL p.e. The intra-arterial blood pressure in the common carotid artery of all animals remained constant. As the cortilymph spaces communicate with the perilymph of the scala tympani, our measured decline of pO2 in the perilymph could indicate a cortilymph hypoxia. During exposure to noise the oxygen-dependent Na+ and K+ pumps, which maintain the ion balance and function of the organ of Corti, can decompensate due to lack of oxygen. That would lead to a K+ contamination of the cortilymph and to an intracellular Na+ accumulation, which can cause microstructural damage (hair cell-cilia fusion, hair cell, synaptic and dendritic swelling, hair cell contraction and sustained depolarization), which would be reflected in the CMs and CAPs. SN - 0017-6192 UR - https://www.unboundmedicine.com/medline/citation/3170282/[Simultaneous_determinations_of_oxygen_partial_pressure_in_the_scala_tympani_electrocochleography_and_blood_pressure_measurements_in_noise_stress_in_guinea_pigs]_ L2 - https://medlineplus.gov/noise.html DB - PRIME DP - Unbound Medicine ER -