Objective: Obstructive sleep apnea (OSA) can provoke cardiovascular impairments. Animal models that mimic OSA can help clarify the roles of changes in sleep architecture and direct effects of apnea on these impairments. This study analyzed the effect of obstructive apneas on sleep structure, and the cardiovascular responses induced by apnea during wakefulness, non-REM sleep, and REM sleep, followed or not by awakening. Methods: Intermittent apneas, 6 s each, once a minute, were made for 8 h in male adult Wistar rats by inflation of a tracheal balloon (Schoorlemmer et al., 2011). Sleep staging was done by analysis of cortical EEG and EMG of the trapezoid muscle as described by Louis et al. (2004). Arterial pressure and ECG were obtained by telemetry. Heart rate and mean pressure were calculated each second, starting 5 s before apnea onset until 10 s after the end of apnea. Results: Apneas did not alter the total time awake (52% with, 44% without apnea), non-REM sleep (39% with, 47% without apnea) and REM sleep (8% with, 10% without apnea (n = 4 rats). Rats awoke in 76% of the apneas made in non-REM sleep, and in 35% of the apneas made in REM sleep. Heart rate and arterial pressure did not change during apnea, independently of the stage of the sleep-wake cycle, and independently of wake-up. Tachycardia was seen after the end of apnea. Heart rate increased by 12 bpm in awake subjects (152 apneas), by 27 bpm when subjects awoke from non-REM sleep (129 apneas), by 3 bpm when subjects failed to wake up from non-REM (28 apneas), by 14 bpm when subjects failed to wake up from REM (19 apneas), and by 29 bpm when subjects woke up from REM (16 apneas). After the end of apnea, arterial pressure fell by 17 mmHg in subjects that woke up from REM, but did not change in the other conditions. Conclusion: This protocol of apneas did not provoke sleep deprivation, which is suggestive of low stress in rats. Apneas that caused awakening were followed by tachycardia, and if the subject woke up from REM sleep, hypotension. Awakening may exert considerable influence on autonomic changes that occur immediately after apnea.