title: Dopamine turnover in rat retina: a 24-hour light-dependent rhythm.
abstract: To examine the pattern of retinal dopamine (DA) turnover during 24 h, DA and 3,4-dihydroxyphenylacetic acid (DOPAC) were measured at 2-h intervals in rats kept in a regular 12-h light-dark cycle. DA and DOPAC were higher during the light and lower during the dark hours. These rhythmic variations were abolished and DA and DOPAC remained low during 24 h of light deprivation. Findings indicate that DA turnover in the retina is accelerated during the light and suppressed during the dark phases of the diurnal light-dark cycle. These fluctuations in retinal DA neuronal activity are not truly circadian but are dependent on environmental lighting as an external stimulator.
mesh_terms: D015102:3,4-Dihydroxyphenylacetic Acid / Q000032:analysis; D000818:Animals; D002940:Circadian Rhythm; D004298:Dopamine / Q000032:analysis*; D008027:Light; D010507:Periodicity; D051381:Rats; D012160:Retina / Q000032:analysis*
chemical_list: D015102:3,4-Dihydroxyphenylacetic Acid; D004298:Dopamine