title: Circadian variation in plasma dopamine levels in man.
abstract: Nocturnal and daytime recumbent secretory patterns of norepinephrine, epinephrine and dopamine were determined at 30 min intervals in 9 normotensive males. Plasma levels of dopamine as well as those of norepinephrine and epinephrine followed a circadian pattern in these recumbent males. Plasma levels of dopamine were more closely related to clock time (r = -0.54, p less than 0.001) than either norepinephrine or epinephrine levels. As for norepinephrine and epinephrine, the sleep period in all 9 males was characterized by a paucity of dopamine secretory peaks as well as lower mean dopamine levels than during the awake state. There was a strong relationship between the circadian changes in plasma dopamine levels and those of norepinephrine (r = 0.92) and epinephrine (r = 0.78) throughout the 24-h period of recumbency. These interrelationships are consistent with a common regulatory mechanism governing the sleep/wake and/or rest/activity in plasma catecholamine levels.
mesh_terms: D000328:Adult; D002940:Circadian Rhythm; D004298:Dopamine / Q000097:blood*; D004837:Epinephrine / Q000097:blood; D006801:Humans; D008297:Male; D008875:Middle Aged; D009638:Norepinephrine / Q000097:blood; D012016:Reference Values; D012890:Sleep / Q000502:physiology
chemical_list: D004298:Dopamine; D009638:Norepinephrine; D004837:Epinephrine