Fenoldopam - But not dopamine - Selectively increases gastric mucosal oxygenation in dogs

Lothar A. Schwarte*, Olaf Picker, Achim W. Schindler, Artur Fournell, Thomas W.L. Scheeren

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review


Objective: To compare the effects of fenoldopam and dopamine on gastric mucosal and systemic oxygenation, and to identify the receptors involved. Design: Randomized controlled animal study. Setting: University research department of experimental anesthesiology. Subjects: Seven anesthetized dogs with chronically implanted ultrasound flow probes around the pulmonary artery for continuous measurement of cardiac output. Interventions: On different days, the dogs received in random order either the selective DA1-agonist fenoldopam (0.1 and 1.0 μg·kg-1·min-1, with or without DA1-blocker pretreatment), dopamine (2.5 and 5.0 μg·kg-1·min-1, with or without α1-blocker pretreatment), or saline (control). Measurements and Main Results: We continuously measured regional microvascular hemoglobin oxygen saturation (μHbO2) In gastric mucosa by reflectance spectrophotometry, and systemic oxygen delivery. Fenoldopam increased gastric mucosal μHbO2 by approximately 20%, and this effect was prevented by selective DA1-receptor blockade. In contrast, dopamine neither alone nor during α1-blockade altered μHbO2. With respect to systemic measures of oxygen transport, fenoldopam had negligible effects, whereas dopamine (with and without α1-blocker pretreatment) dose-dependently increased cardiac output and systemic oxygen delivery by approximately 30%. Conclusions: Fenoldopam dose-dependently increased microvascular oxygenation of the gastric mucosa without changing systemic oxygen transport, i.e., this drug acted selectively on the splanchnic mucosa. The increase in gastric mucosal oxygenation was mediated by DA1-receptors. In contrast, dopamine markedly increased systemic oxygen transport, but did not affect microvascular oxygenation of gastric mucosa. This lacking effect on gastric mucosal oxygenation was not caused by α1-mediated vasoconstriction. The regional effects of both catecholamines could not be deduced from systemic hemodynamics and oxygenation.

Original languageEnglish
Pages (from-to)1999-2005
Number of pages7
JournalCritical Care Medicine
Issue number7
Publication statusPublished - 1 Jul 2003

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