Abstract
Summary: The effect of alpha-adrenergic blockade by phentolamine on the pulmonary vascular response to dopamine was studied in chronically prepared newborn lambs. Dopamine was administered at doses of 2.7 μg·kg-1·min-1, 27 μ·kg-1·min-1 and 270μg·kg-1·min-1 with and without alpha-adrenergic blockade. Dopamine infusion at 270 μ·kg-1·min-1 caused a rise in the mean pulmonary artery pressure from 22 ± 3.2 mmHg (mean ± S.E.) at baseline to 36 ± 4.1 mmHg (P < 0.001). This rise was unaffected by alpha-adrenergic blockade. Dopamine infusion alone did not change pulmonary blood flow, but, in the presence of alpha-adrenergic blockade, pulmonary blood flow rose from 190 ± 12 ml·min-1·kg-1 at baseline to 280 ± 13 ml·min-1·kg-1 at the maximum dopamine infusion rate (P < 0.001). Pulmonary vascular resistance was the same before and after alpha-adrenergic blockade and did not change from the baseline value during dopamine infusion.
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Williams, B., Drummond, W. The Effect of Alpha-Adrenergic Blockade on the Pulmonary Vascular Response to Dopamine in Neonatal Lambs. Pediatr Res 17, 464–467 (1983). https://doi.org/10.1203/00006450-198306000-00007
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DOI: https://doi.org/10.1203/00006450-198306000-00007
