Changes in regional vascular capacitance during prostacyclin-induced cardiac vagal reflex in pigs

Intestinal and liver blood volumes were measured by blood-pool scintigraphy in anesthetized pigs. A prostaglandin I2-induced shift in the intestinal vascular pressure-volume relationship suggests that blood volume increases by an active change in vascular capacitance, whereas reductions in liver blood volume and left ventricular end-diastolic pressure appear to be due to passive mechanisms related to the shift of blood volume to the intestinal circulation.