Effect of rapid eye movement sleep deprivation on allergen-induced airway responses in a rat model of asthma

Background: Nocturnal airway narrowing is a common characteristic of asthma that remains poorly understood. Sleep itself or rapid eye movement (REM) sleep has been suspected to play a role in the etiology of nocturnal asthma; however, only inconsistent findings have so far been produced. The purpose of this study was to examine the effect of sleep deprivation, particularly REM sleep, using the classical platform (flowerpot) method on asthmatic responses in a rat model of asthma, in a situation of immobilization stress. Methods: After the rats had been randomly divided into three groups of 9 including (1) a caged control group, (2) a large (sham) platform group, and (3) a small platform group, we investigated the effect of REM sleep deprivation over a 72-hour period on both the antigen-induced immediate asthmatic response (IAR) and late asthmatic response (LAR) including the changes of stress hormones. Results: The small platform group showed significantly lower plasma histamine levels and higher plasma adrenaline levels during the IAR compared to the control group (p < 0.05). The number of eosinophils in either the bronchoalveolar lavage fluid or the bronchial lamina propria during the LAR in the small platform group was reliably suppressed compared to the other groups (p < 0.05). No significant differences were found in the plasma corticosterone and noradrenaline levels among the three groups, irrespective of the phase of the asthmatic response. Conclusions: Our results indicate that REM sleep contributes to nocturnal asthma, possibly due to an alteration of the sympathetic nervous function.