The dopamine DA-1 receptor agonist fenoldopam enhances amino-acid-induced hyperemia in dogs.
The effect of the dopamine DA-1 receptor agonist fenoldopam on amino-acid-induced glomerular hyperemia and hyperfiltration was evaluated in conscious chronically instrumented dogs. Infusion of either amino acids (L-alanine, 4.1 mg/kg.min; L-proline, 3.2 mg/kg.min; L-serine, 2.9 mg/kg.min) or fenoldopam (0.05 micrograms/kg.min) alone resulted in significant (p < 0.05) increases in renal plasma flow of 85 +/- 41 and 53 +/- 24%, respectively. In dogs infused with both amino acids and fenoldopam, there was a dramatic (143 +/- 27%) increase in renal plasma flow (p < 0.01). This response was significantly greater than either treatment alone. The glomerular filtration rate did not change significantly when fenoldopam was infused; however, it increased to a similar degree when dogs were infused with either amino acids or a combination of fenoldopam and amino acids. The data suggest that fenoldopam either acts synergistically with amino acids to increase renal blood flow or perhaps magnifies the renal functional reserve.
Brooks
D P
DP
Department of Renal Pharmacology, SmithKline Beecham Pharmaceuticals, King of Prussia, Pa 19406-0939.
DePalma
D
D
D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine / Q000031:analogs & derivatives* / Q000494:pharmacology; D000409:Alanine; D000596:Amino Acids; D000818:Animals; D004285:Dogs; D015259:Dopamine Agents / Q000494:pharmacology*; D004357:Drug Synergism; D005260:Female; D018818:Fenoldopam; D005919:Glomerular Filtration Rate; D006940:Hyperemia / Q000139:chemically induced / Q000503:physiopathology*; D011392:Proline; D012079:Renal Circulation / Q000187:drug effects*; D012694:Serine; D012964:Sodium / Q000652:urine
D000596:Amino Acids; D015259:Dopamine Agents; D012694:Serine; D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine; D011392:Proline; D012964:Sodium; D018818:Fenoldopam; D000409:Alanine