title: Circadian phase dependent pharmacokinetics of L-dopa, its main metabolites (3-OMD, HVA, DOPAC) and carbidopa in rats.
abstract: This study aims to evaluate whether or not the kinetics of L-dopa, its main metabolites (3-O-methyldopa, 3-OMD, homovanilic acid, HVA and 3,4-dihydroxyphenylacetic acid, DOPAC) and carbidopa, vary according to the 24-hour scale in rats. Four groups of seven adult male Wistar AF EOPS rats were used for these experiments; each group received L-dopa (200 mg.kg-1 ip) and carbidopa (20 mg.kg-1 ip) at 1000, 1600, 2200 or 0400 hours. L-dopa, 3-OMD, DOPAC, HVA and carbidopa were simultaneously determined by specific ion-pair reversed-phase high performance liquid chromatography with electrochemical detection. A temporal variation of the kinetics of both L-dopa and carbidopa was demonstrated with higher plasma clearance and lower area under concentration curve after the administration at 2200 hours. Moreover, a temporal variation of the metabolism of L-dopa was indirectly documented by temporal variation in kinetics of 3-OMD, DOPAC and HVA.
authors.affiliation: Laboratoire de Pharmacologie Médicale et Clinique, Faculté de Médecine de Marseille, France.
authors.forename: M H
authors.initials: MH
authors.lastname: Andre
authors.forename: S
authors.initials: S
authors.lastname: Grignon
authors.forename: B
authors.initials: B
authors.lastname: Bruguerolle
mesh_terms: D015102:3,4-Dihydroxyphenylacetic Acid / Q000097:blood / Q000493:pharmacokinetics*; D000704:Analysis of Variance; D000818:Animals; D019540:Area Under Curve; D002230:Carbidopa / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D002940:Circadian Rhythm; D006207:Half-Life; D006719:Homovanillic Acid / Q000097:blood / Q000493:pharmacokinetics*; D007980:Levodopa / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D008297:Male; D008750:Methyldopa / Q000097:blood / Q000493:pharmacokinetics*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D015102:3,4-Dihydroxyphenylacetic Acid; D007980:Levodopa; D008750:Methyldopa; D002230:Carbidopa; D006719:Homovanillic Acid