Hyperosmolality and pancreatic blood flow.

In the cat pancreas, close intra-arterial infusions of hypertonic xylose, glucose and sucrose solutions caused a marked vasodilatation but no secretion. The magnitude of the vasodilator response correlated with the degree of induced glandular hyperosmolality but not with the substance per se. Stimulation of the vagus nerve as well as infusion of secretin and/or CCK evoked a pronounced secretion and a small to moderate increase in pancreatic blood flow, but did not significantly change the plasma osmolality in the venous effluent from the gland. Bradykinin, papaverine and isoprenaline caused large increments of pancreatic blood flow; none of these drugs evoked secretion nor did they change the venous osmolality. It is concluded that blood-bone hyperosmolality is a strong stimulus for pancreatic vasodilatation, but the functional hyperaemia of this gland is due to factors other than regional tissue hyperosmolality.