title: Clonidine and sympathetic activity during sleep.
abstract: 1. Blood pressure, heart rate, plasma noradrenaline and electroencephalographic variables were measured simultaneously during sleep in five healthy males before and after slow-release clonidine (300 micrograms orally) or placebo. 2. The blood pressure fall during sleep correlated significantly with the depth of sleep. 3. Clonidine significantly reduced systolic blood pressure during sleep and profoundly reduced total paradoxical sleep duration. 4. Plasma noradrenaline declined progressively during the sleep period and concentrations were significantly lower after clonidine compared with placebo.
mesh_terms: D000328:Adult; D001794:Blood Pressure / Q000187:drug effects; D003000:Clonidine / Q000494:pharmacology*; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D008297:Male; D009638:Norepinephrine / Q000097:blood; D012894:Sleep Stages / Q000187:drug effects* / Q000502:physiology; D013564:Sympathetic Nervous System / Q000187:drug effects* / Q000502:physiology
chemical_list: D003000:Clonidine; D009638:Norepinephrine