Renal dopaminergic system activity in the rat remnant kidney

• Type: Article in International Scientific Journal
• Date: 2005

Authors

sampaio-maia, b (Author) FCNAUP; serrao, p (Author) Other; guimaraes, jt (Author) FMUP; vieira-coelho, ma (Author) FMUP; pestana, m (Author) FMUP

Journal

Title: Nephron - Experimental Nephrology

Vol. 99 No. 2

Pages: E46-E55

ISSN: 1660-2129

Publisher: S. Karger AG

Indexing

ISI Web of Knowledge - 24 Citations

ISI Web of Science

Scopus - 25 Citations

Pubmed / Medline

Scientific classification

FOS: Medical and Health sciences > Clinical medicine

CORDIS: Health sciences

Other information

Authenticus ID: P-000-6B2

DOI: 10.1159/000082868

Abstract (EN): Background: Renal dopamine exerts natriuretic and diuretic effects by activating D(1)-like receptors. Uninephrectomy results in increased renal dopaminergic activity and dopamine-sensitive enhanced natriuresis. Methods: The present study evaluated renal adaptations in sodium handling and the role of dopamine in rats submitted to 3/4 neprectomy: right nephrectomy and excision of both poles of the left kidney (3/4nx rats). Results: Two weeks after surgery the absolute urinary levels of dopamine were markedly reduced in 3/4nx rats whereas the urinary dopamine excretion per % of residual nephrons was significantly increased in the remnant kidney of 3/4nx rats. The V(max) values for renal aromatic L-amino acid decarboxylase, the enzyme responsible for the synthesis of renal dopamine, were decreased in 3/4nx rats. Renal catechol-O-methyltransferase activity, the enzyme responsible for the methylation of dopamine, was increased in 3/4nx rats whereas the renal activities of monoamine oxidases A and B did not differ between 3/4nx and Sham animals. Volume expansion (5% body weight) resulted in similar natriuretic responses in 3/4nx and Sham rats. During D(1) antagonist administration (Sch-23390, 30 mug.h(-1).kg(-1)) the natriuretic response to volume expansion was reduced in 3/4nx rats more pronouncedly than in Sham animals. Conclusion: The decrease in absolute renal dopamine output in 3/4nx rats is related with reduced renal synthesis and enhanced O-methylation of the amine. However, this is accompanied in 3/4nx rats by increased renal dopamine excretion per residual nephrons and dopamine-sensitive enhanced natriuresis. Copyright (C) 2005 S. Karger AG, Basel.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 10