Faculty Collaboration Database

Effects of L-DOPA/carbidopa administration on the levels of L-DOPA, other amino acids and related compounds in the plasma, brain and heart of the rat. Pharmacology 1997 Sep;55(3):109-16

Date

11/05/1997

Pubmed ID

9346399

DOI

10.1159/000139518

Scopus ID

2-s2.0-0030809589 (requires institutional sign-in at Scopus site)   11 Citations

Abstract

Rats were treated intraperitoneally with a mixture of 250 mg/kg L-DOPA and 40 mg/kg carbidopa or with vehicle and sacrificed 30 min later. Plasma, heart and cortex, midbrain, brainstem and cerebellum were removed from each animal and assayed by HPLC for L-DOPA and a large number of amino acids and related amino compounds. L-DOPA levels increased from undetectable (<0.2 nmol/ml or g) to 1,146, 1,007, 399, 376, 368 and 850 nmol/ml or g in the above tissues. In addition, several amino compounds were significantly affected by L-DOPA/carbidopa (p < or = 0.01). Plasma concentrations of phosphoserine, oxidized glutathione, citrulline, phenylalanine, tyrosine and 1-methylhistidine increased and arginine, glutamic acid and lysine decreased. In the heart, concentrations of phosphoserine, taurine, reduced glutathione, threonine, serine, glutamine, glycine, alanine, valine, GABA, ethanolamine, ammonia and arginine decreased. In the cortex, camosine and homocarnosine increased. In the midbrain, valine increased and leucine, ornithine and oxidized glutathione decreased. In the cerebellum, citrulline increased. In the brainstem, threonine, serine, asparagine, glutamine, oxidized glutathione, alanine, and leucine decreased. In the brainstem, arginine was slightly decreased with a concomitant increase in citrulline (p < 0.05), indicative of nitrous oxide formation. These results show that administration of L-DOPA/ carbidopa not only raises dopamine levels but can also affect other biochemicals and that the observed changes in amino acids and related compounds can perhaps contribute to the beneficial and/or adverse effects of L-DOPA/carbidopa therapy of Parkinson's disease.

Author List

Diederich C, Milakofsky L, Hare TA, Hofford JM, Dadmarz M, Vogel WH

Author

Christian Diederich MD Assistant Professor in the Anesthesiology department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Amino Acids
Animals
Aromatic Amino Acid Decarboxylase Inhibitors
Brain
Brain Stem
Carbidopa
Cerebellum
Cerebral Cortex
Enzyme Inhibitors
Levodopa
Male
Mesencephalon
Myocardium
Rats
Rats, Sprague-Dawley