Effect of adrenergic blockers on the dog's sleep-wake pattern

Different results are reported for the effects of an alpha and beta adrenergic blocker on the 24-hr sleep-wake patterns in dogs. While propranolol did not affect the 24-hr sleep-wake parameters, phentolamine significantly reduced delta sleep (stage 2), shortened the length of the sleep episodes, and decreased the number of REM episodes in each sleep-wake cycle. Phentolamine effects are explained by increased arousals within sleep episodes.