Animal Model Of Obstructive Sleep Apnea Hypopnea Syndrome In Rats

OBJECTIVE:The obstructive sleep apnea hyponea syndrome(OSAHS) was a prevalent disease,characterized by sleep apnea and hypoapnea induced by repetitive collapse and occlusion of the upper airway,snoring,excessive daytime sleepiness,the change of the sleep architecture and the decent of saturation of blood oxygen during sleep.It do harm to many organs and systems,and therefore It draws attentions of many researchers in China and abroad.The aim of this study was to build up a steady and credible animal model to study the pathogenesis,pathological and physiological changes,and complication of OSAHS.METHODS:1.Anesthesia:The operation and sleep monitoring were performed under different dose of pentobarbital sodium anesthesia.2.Injection of Sodium Hyaluronate:After anesthesia,the Sodium Hyaluronate was injected into the palatoglossal arch,palatopharyngeal arch and root of tongue of eight Wistar rats until the rats showd apnea.During the injection,observe the breathing to prevent the rats from death because of asphyxia.3.Signal collection:The electroencephalogram(EEG),electromyogram(EMG) and oro-nasal airflow(AIRFLOW) were recorded by reformed PSG.4.Signal analysis:The signal was analyzed manually. 4.1 Scoring of the wake/sleep states:Wake/sleep state was characterized as either wake state(high-frequency and low-amplitude EEG,and increased EMG) and sleep state(low-frequency and high-amplitude EEG,and decreased EMG).4.2 Apnea:It was scored as one apnea when the respiratory wave has been away for more than 2.5 seconds.The apnea index(AI) was recorded for each rat when It was under wake or sleep state.4.3 Longest apnea time(Ltime):The longest apnea time was recorded for each rat when It was under wake or sleep state.5.Statistical analysis:The data was analyzed with SPASS 10.0 software.The difference in AI and Ltime before and after the injection was analyzed with paired t-test,the difference in AI and Ltime between WAKE and SLEEP was also analyzed with paired t-test.RESULTS:1.General condition:All animals ate normally after injection,and survived 4 weeks after injection.No sign of infection in the cavity of pharynx was found.2.When the animals were under light anesthesia,the electroencephalogram and electromyogram were similar to the non-rapid eye movement sleep state(NREM)(high-frequency and low-amplitude EEG,and increased EMG),no rapid eye movement sleep state(REM) was found(high-frequency and low-amplitude EEG, and very decreased EMG).3.All animals showed apnea with unusual movement of the thorax and abdomen before and 4 weeks after the injection,but The difference in AI and Ltime bitween before and 4 weeks after the injection of Sodium Hyaluronate was obvious(P＜0.05).4.Animals showed obstructive apnea in either wake or sleep state,but The difference in AI and Ltime between WAKE and SLEEP was obvious(P＜0.05)CONCLUSIONS:The animal model of OSAHS in rats made by injection of Sodium Hyaluronate was steady,credible and similar to the OSAHS of human beings,It can be used to study the pathogenesis,pathological and physiological changes,and complication of OSAHS.