Neurogenic Model of Obstructive Sleep Apnea in Rabbits

Abstract

Objectives: An animal model of obstructive sleep apnea (OSA) can be helpful for evaluating the pathophysiology of OSA and application of novel treatment modalities. This study aimed to establish new OSA animal model simulating real upper airway conditions during sleep. Methods: A total of 27 New Zealand white male rabbits were used. Sleep was induced by intramuscular injection of 0.3 ml/kg of Zoletil and 0.2 ml/kg of Rompun. Drug-induced sleep was evaluated using Embletta X100 for electroencephalography, electrooculography, chin electromyography, nasal airflow, breathing efforts, and pulse oxymetry. Upper airway obstruction was induced by injecting botulinum toxin into the genioglossus. Respiratory events (apneas or hypopneas) during sleep were evaluated using ApneaLink. Results: All the rabbits showed no apneas or hypopneas before injection of botulinum toxin. In the control rabbits injected with normal saline, apneas or hypopneas were not found. The respiratory events were observed in 5 of 8 rabbits injected with 2.5 units of botulinum toxin whereas they were observed in 7 of 10 rabbits injected with 5.0 units of botulinum toxin. The median AHI was 9.6 (5.3 – 14.8)/h and 45.6 (21.5 – 70.5)/h in the rabbits injected with 2.5 units and 5.0 units of botulinum toxin, respectively ( P = .028). Conclusions: The animal model of OSA could be developed by paralyzing the genioglossus in rabbits.