The effects of indomethacin and hemorrhage on splanchnic blood flow.

The role of prostaglandins in regulating splanchnic blood flow during hemorrhage has been investigated in the anesthesized dog using the microsphere technique. Indomethacin selectively decreased blood flow to the gastrointestinal tract, but did not change hepatic arterial flow. Hemorrhage (5 ml/kg and 10 ml/kg) generally increased peripheral resistance in the gastrointestinal tract as much as total peripheral resistance was increased. However, resistance in the stomach and pancreas increased to a greater extent while there was no change in hepatic arterial resistance. The effect of hemorrhage on splanchnic blood flow distribution was not changed by prior indomethacin treatment. Thus, prostaglandins contribute to the regulation of basal flow to the gastrointestinal tract but are not involved in regulatory changes in splanchnic blood flow during hemorrhage. The enhanced sensitivity of the gastric and pancreatic vascular beds to hemorrhage may contribute to local toxicity during hemorrhage.