Role of chronic inhibition of dopamine-metabolizing enzymes in the regulation of renal sodium and phosphate excretion in the rat remnant kidney.

• Type: Article in International Scientific Journal
• Date: 2006

Authors

Benedita Sampaio-Maia (Author) FMDUP; Mónica Rodrigues (Author) ICBAS; Pestana M (Author) FMUP

Journal

Title: Nephron - Physiology

Vol. 103 No. 1

Pages: 14-24

ISSN: 1660-2137

Publisher: S. Karger AG

Indexing

ISI Web of Knowledge - 12 Citations

ISI Web of Science

Scopus - 12 Citations

Pubmed / Medline

Scientific classification

FOS: Medical and Health sciences > Other medical sciences

Other information

Authenticus ID: P-004-QCV

Abstract (EN): BACKGROUND/AIMS: The present study examined the effects of chronic selective or combined inhibition of type A monoamine oxidase (MAO) and catechol-O-methyltransferase (COMT) on daily urinary excretion of dopamine and metabolites and on natriuresis and phosphaturia in 3/4 nephrectomized (3/4nx) and Sham rats. METHODS: The 3/4nx and Sham rats were placed in metabolic cages and received the MAO-A-selective inhibitor Ro-411049 (7.5 mg x kg(-1) bid) and/or the COMT-selective inhibitor BIA 3-202 (30 mg x kg(-1) bid) orally for 3 days during high sodium diet. RESULTS: Selective COMT inhibition increased the urinary excretion of the deaminated metabolite (3,4-dihydroxyphenylacetic acid, DOPAC) and decreased the urinary excretion of the methylated (3-methoxytyramine, 3-MT) and deaminated plus methylated metabolite (homovanillic acid, HVA) in both groups. Selective MAO-A inhibition increased the urinary excretion of 3-MT and reduced the urinary excretion of both DOPAC and HVA in either 3/4nx or Sham rats. Combined inhibition of MAO-A and COMT did not significantly change the urinary excretion of DOPAC and markedly decreased the urinary excretion of 3-MT and HVA in both groups. Selective or combined inhibition of MAO-A and COMT did not alter the daily urinary excretion of dopamine, sodium or phosphate in either 3/4nx or Sham rats. CONCLUSIONS: Chronic selective or combined inhibition of MAO-A and COMT is not of major importance in regulating the dopamine-dependent natriuresis and phosphaturia in either 3/4nx or Sham rats.

Language: English

Type (Professor's evaluation): Scientific