Korean J Otorhinolaryngol-Head Neck Surg.  2010 Dec;53(12):749-754. 10.3342/kjorl-hns.2010.53.12.749.

Correlation between Dose of Ethacrynic Acid and Weight of Cat in the Cat Deafening Procedure

• Jang JH
• Lee HS
• Kim HY
• Lee JH
• Chang SO
• Oh SH
• Park MH

• KMID: 2277169
• DOI: http://doi.org/10.3342/kjorl-hns.2010.53.12.749

Abstract

BACKGROUND AND OBJECTIVES
Co-administration of kanamycin (KM) with the loop diuretic ethacrynic acid (EA) has been known to produce a rapid and profound hearing loss in adult animals. The objective of this study was to see if monitoring the hearing status during intravenous infusion of EA could minimalize individual variability and to evaluate the correlation between the dose of EA and the body weight (wt). MATERIALS AND METHOD: Twenty cats with the mean age of 24 weeks+/-3.7 (range, 20.6-28.3 weeks) and the mean weight of 3.27 kg+/-0.75 (range 2.4-4.75 kg) received a subcutaneous injection of KM (300 mg/kg) followed by an intravenous infusion of EA (1 mg/min). Click evoked auditory brainstem responses (ABRs) were recorded to monitor the hearing during the infusion. When the ABR thresholds rose to levels in excess of 90 dB SPL, the infusion of EA was stopped. The histopathologies for sections of apex, middle, base of cochlea were examined after 6 months.
RESULTS
There was a significant positive correlation (p<.001, r2=.583) between the EA dose and body weight. Cochlear histopathology showed an absence of organ of Corti and decrease of spiral ganglion cells in the majority of cochleas, especially in the basal turn. The extent of loss of spiral ganglion cells was dependent on their distance from the round window.
CONCLUSION
Monitoring the animal's hearing status during the procedure ensured that the dose of EA was optimized for individual animals. Thus, the positive correlation between the EA dose and body weight should be considered should in designing the animal models of controlled high frequency hearing loss.

Keyword

Ethacrynic acid; Cochlea; Deafness; Aminoglycosides

MeSH Terms

Adult
Aminoglycosides
Animals
Body Weight
Cats
Cochlea
Deafness
Ethacrynic Acid
Evoked Potentials, Auditory, Brain Stem
Hearing
Hearing Loss
Humans
Infusions, Intravenous
Injections, Subcutaneous
Kanamycin
Models, Animal
Organ of Corti
Organothiophosphorus Compounds
Spiral Ganglion
Aminoglycosides
Ethacrynic Acid
Kanamycin
Organothiophosphorus Compounds