title: Slow increase of homovanillic acid in cerebrospinal fluid after levodopa administration.
abstract: Concentrations of major catabolites of dopamine were followed in the ventricular cerebrospinal fluid (CSF) in five patients undergoing intracranial pressure monitoring for chronic hydrocephalus. Determinations were made every 2 h following the administration of carbidopa/levodopa 25/250 mg (one Sinemet capsule) given 8 h apart. The rise of homovanillic acid (HVA) concentrations was slow and progressive, reaching the level of statistical significance (p < or = 0.01) only 8 h after the second administration of Sinemet. The rise in 3,4-dihydroxyphenylacetic acid (DOPAC) was faster than the rise in HVA, with the peak value detected 4 h after the first administration of Sinemet. These data are interpreted as a confirmation, in humans, of a slow pool of exogenous levodopa, previously demonstrated in animal studies.
authors.affiliation: Service de Neurochirurgie, Hôpital Erasme, Université Libre de Bruxelles, Belgium.
authors.forename: C
authors.initials: C
authors.lastname: Raftopoulos
authors.forename: S
authors.initials: S
authors.lastname: Dethy
authors.forename: M A
authors.initials: MA
authors.lastname: Laute
authors.forename: S
authors.initials: S
authors.lastname: Goldman
authors.forename: A B
authors.initials: AB
authors.lastname: Naini
authors.forename: S
authors.initials: S
authors.lastname: Przedborski
authors.forename: J
authors.initials: J
authors.lastname: Hildebrand
mesh_terms: D015102:3,4-Dihydroxyphenylacetic Acid / Q000134:cerebrospinal fluid; D000368:Aged; D000978:Antiparkinson Agents / Q000494:pharmacology*; D002230:Carbidopa / Q000493:pharmacokinetics / Q000494:pharmacology*; D004334:Drug Administration Schedule; D004338:Drug Combinations; D005260:Female; D006719:Homovanillic Acid / Q000134:cerebrospinal fluid*; D006801:Humans; D006849:Hydrocephalus / Q000134:cerebrospinal fluid; D007980:Levodopa / Q000493:pharmacokinetics / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged
chemical_list: D000978:Antiparkinson Agents; D004338:Drug Combinations; C009265:carbidopa, levodopa drug combination; D015102:3,4-Dihydroxyphenylacetic Acid; D007980:Levodopa; D002230:Carbidopa; D006719:Homovanillic Acid