title: Dopaminergic instability in children with orthostatic dysregulation.
abstract: Effects of postural change on plasma catecholamine levels were examined in 53 children with orthostatic dysregulation (OD). Special interest was focused on plasma dopamine and dopamine-beta-hydroxylase (DBH) activity, since one patient showed a prominent rise in plasma dopamine from 822 pmol/L to 126 nmol/L in postural change. She had a wide fluctuation of plasma dopamine from 209 pmol/L to 305 nmol/L during 12 hours of observation period, but plasma norepinephrine and epinephrine remained within the normal range as well as urinary excretion of catecholamines. Of 52 children with OD, 11 had a marked increase in plasma dopamine, whereas 11 showed a reduction of it by postural change. Plasma DBH activity was significantly decreased in the former (81 +/- 14 nmol/h/ml), while it was elevated in the latter (320 +/- 48 nmol/h/ml, P less than 0.001 vs the former), although DBH activity in individuals was not affected by postural change. These results indicate the involvement of dopaminergic instability as a cause of OD in childhood.
authors.forename: T
authors.initials: T
authors.lastname: Sato
authors.forename: N
authors.initials: N
authors.lastname: Igarashi
authors.forename: H
authors.initials: H
authors.lastname: Maruyama
authors.forename: T
authors.initials: T
authors.lastname: Okabe
mesh_terms: D000293:Adolescent; D001794:Blood Pressure; D002648:Child; D004298:Dopamine / Q000097:blood*; D004299:Dopamine beta-Hydroxylase / Q000097:blood*; D004837:Epinephrine / Q000097:blood; D005260:Female; D006801:Humans; D007024:Hypotension, Orthostatic / Q000097:blood*; D007564:Japan; D008297:Male; D009638:Norepinephrine / Q000097:blood; D011187:Posture
chemical_list: D004299:Dopamine beta-Hydroxylase; D004298:Dopamine; D009638:Norepinephrine; D004837:Epinephrine