Indomethacin-induced reduction in neonatal piglet mesenteric blood flow is blunted by dopexamine

Abstract Background: Dopexamine is a specific dopaminergic and β 2 -adrenergic agonist. Using newborn piglets, we have previously shown that (1) dopexamine increases cardiac output and mesenteric blood flow; (2) indomethacin reduces mesenteric blood flow. Methods: Ultrasonic blood flow probes were placed around the ascending aorta, cranial mesenteric artery, and a renal artery of 0 to 2-day-old and 2-week-old piglets. Animals of each age were grouped (5 to 8 animals per group) and subjected to one of three experimental protocols: (1) 0.4 mg/kg indomethacin infusion, (2) 10 μg/kg/min dopexamine infusion begun 10 minutes before indomethacin, or (3) no treatment. Results: Control animals demonstrated no significant alterations in mesenteric blood flow. Compared with baseline, indomethacin produced significant ( P v 17.9 ± 3.7 mL/min at 90 min), and 2-week-old (80.2 ± 12.5 mL/min v 29.7 ± 5.7 mL/min at 90 minutes) piglets. In both animal groups treated with dopexamine before indomethacin, the decreases in cranial mesenteric artery blood flow were eliminated (38.4 ± 7.6 mL/min at baseline v 36.5 ± 6.8 mL/min at 90 minutes in 0 to 2 day olds; 79.9 ± 10.0 mL/min at baseline v 77.5 ± 14.7 mL/min in 2 week olds). Indomethacin-induced declines in renal blood flow were similarly abrogated by dopexamine. Conclusion: Dopexamine may prove of clinical benefit when a neonate is considered a candidate for indomethacin therapy.