The effect of secretin on peripheral arterial blood flow

Arterial blood flow was measured in 18 arteries leading to nearly all major organs in the anesthetized dog, to obtain information about the specificity of the blood flow effects caused by secretin. This gastro-intestinal hormone was administered intravenously in a sequence of bolus injections (0.001--4 U/kg). Blood flow increase in the pancreatico-duodenal arteries was highest of all arteries observed. This flow increase in the superior pancreatico-duodenal artery was also found in its truncal artery (gastroduodenal a.), but to a less extend: the effect was diluted by the other--less reacting--branch (right gastro-epiploic a.) of the same truncal artery. We conclude that secretin preferentially increased blood flow in the pancreatico-duodenal arteries. Since secretin effects on heart rate and arterial pressure were but small, the flow increase in the pancreatico-duodenal area were caused by a lowering of the resistance of the pancreatico-duodenal vasculature. Comparison between the flow responses, elicited by secretin (Boots) and secretin (Karolinska), is discussed.