INDOMETHACIN-INDUCED REDUCTION IN NEONATAL PIGLET MESENTERIC BLOOD-FLOW IS BLUNTED BY DOPEXAMINE

Background: Dopexamine is a specific dopaminergic and beta(2)-adrenerg ic agonist. Using newborn piglets, we have previously shown that (1) d opexamine increases cardiac output and mesenteric blood flow; (2) indo methacin reduces mesenteric blood flow. Methods: Ultrasonic blood flow probes were placed around the ascending aorta, cranial mesenteric art ery, and a renal artery of 0 to 2-day-old and 2-week-old piglets. Anim als 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 inf usion, (2) 10 mu g/kg/min dopexamine infusion begun 10 minutes before indomethacin, or (3) no treatment. Results: Control animals demonstrat ed no significant alterations in mesenteric blood flow. Compared with baseline, indomethacin produced significant (P < .05, analysis of vari ance) declines in cranial mesenteric artery blood flow in 0 to 2-day o ld (37.2 +/- 5.7 mL/min v 17.9 +/- 3.7 mL/min at 90 min), and 2-week-o ld (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, th e decreases in cranial mesenteric artery blood flow were eliminated (3 8.4 +/- 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/m in in 2 week olds). Indomethacin-induced declines in renal blood flow were similarly abrogated by dopexamine. Conclusion: Dopexamine may pro ve of clinical benefit when a neonate is considered a candidate for in domethacin therapy. Copyright (C) 1998 by W.B. Saunders Company.