CARDIOPULMONARY INTERACTIONS FOLLOWING REM-SLEEP DEPRIVATION IN SPRAGUE-DAWLEY RATS

We characterized the effects of 48 h of rapid-eye-movement (REM) sleep deprivation on cardiovascular and respiratory variables and on sleep- related cardiopulmonary interactions in adult male Sprague-Dawley rats . Rats were instrumented for monitoring EEG, EMG, and aortic blood pre ssure. Respiratory rate and minute ventilation were measured by unrest rained single-chamber plethysmography. By using radiotelemetry to moni tor blood pressure we clearly demonstrated progressive decreases in me an blood pressure with transitions from wakefulness to non-rapid-eye-m ovement and REM sleep which were unaffected by REM sleep deprivation. Mirror-image state-dependent increases in heart period suggest that ba roreflexes were augmented during sleep with respect to wakefulness. RE M sleep deprivation was also associated with lower blood pressure and longer heart period over all sleep/wake states, although this achieved statistical significance only during REM sleep and only during the fi rst hour of recovery sleep. These cardiovascular changes coupled with the observed decreases in respiratory rate and minute ventilation sugg est a further augmentation of baroreflexes following REM sleep depriva tion. (C) 1997 Academic Press.