Heart failure, aging, and renal synthesis of dopamine

• Tipo: Artigo em Revista Científica Internacional
• Data: 2001

Autores

Ferreira A (Autor) Outra; Bettencourt P (Autor) FMUP; Pestana M (Autor) FMUP; Correia, Flora (Autor) FCNAUP; Maria Paula Serrão (Autor) FMUP; Martins, L (Autor) Outra; Cerqueira Gomes, M (Autor) Outra; soares-da-silva, p (Autor) FMUP

Revista

Título: American Journal of Kidney Diseases

Vol. 38

Páginas: 502-509

ISSN: 0272-6386

Editora: Elsevier

Indexação

ISI Web of Knowledge - 7 Citações

Scopus - 16 Citações

Outras Informações

ID Authenticus: P-000-TAT

DOI: 10.1053/ajkd.2001.26834

Abstract (EN): The present study evaluates renal dopaminergic activity in 23 patients with heart failure (NF), 10 age-matched controls, and 10 young subjects during normal-salt (NS) intake and after 8 days of low-salt (LS) intake (patients with HF and age-matched controls only). LS intake produced a marked reduction in urine volume in patients with HF but failed to affect urine volume in age-matched controls. Urinary sodium and fractional excretion of sodium were markedly reduced by LS intake in patients with HF and age-matched controls. Daily urinary excretion of L-3,4-dihydroxyphenylalanine (L-dopa) and dopamine was lower in patients with HF than in age-matched controls. LS intake failed to alter L-dopa and dopamine urinary excretion in control subjects. In patients with HF, LS intake produced a significant decrease in urinary L-dopa excretion, but failed to alter the urinary excretion of dopamine. No significant differences were observed in urinary L-dopa, dopamine, and dopamine metabolite levels between aged controls and young healthy subjects. Urinary dopamine-L-dopa ratios in patients with HF on LS intake (24.5 +/- 7.1) were significantly greater than those with NS intake (11.6 +/- 1.3). Urinary dopamine-L-dopa ratios in old control subjects (LS, 9.7 +/- 1.3; NS, 9.3 +/- 1.1) did not differ from those in young healthy subjects (9.2 +/- 0.8). LS intake produced a marked increase in plasma aldosterone levels in both patients with HF (84.6 +/- 14.4 to 148.2 +/- 20.4 pg/mL; P = 0.0008) and controls (102.1 +/- 13.4 to 151.6 +/- 15.7 pg/mL; P < 0.04). Plasma norepinephrine levels were not significantly affected by LS intake in controls (5.1 +/- 1.62 to 6.3 +/- 1.6 pmol/mL; P = 0.22), but were significantly increased in patients with HF (5.8 +/- 0.8 to 7.1 +/- 0.9 pmol/mL; P = 0.04). In conclusion, patients with HF are endowed with an enhanced ability to take up (or decarboxylate) filtered L-dopa, which might counterbalance the reduced renal delivery of L-dopa, contributing to a relative preservation of dopamine synthesis. This may result as a compensatory mechanism, activated by stimuli leading to sodium reabsorption. Age seems to have no influence on renal dopamine production. (C) 2001 by the National Kidney Foundation, Inc.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 8