The role of plasma kinin in functional vasodilatation in the pancreas.

1. Freshly collected pancreatic juice of the cat contained active kinin-forming enzyme (kallikrein) and, in addition, an active kininase.2. In response to successive doses of secretin, the kinin-forming activity of pancreatic juice fell off considerably. It was restored by pancreozymin.3. Stimulation of the dorsal vagus nerve caused an increase in venous outflow from the pancreas which was greater and more consistently seen when the splanchnic nerves had been sectioned.4. Intravenous injection of highly purified secretin usually had no effect on the outflow, whereas pancreozymin increased it up to 5 times.5. When the pancreas was perfused with oxygenated Locke solution, the effluent contained some kinin-forming enzyme when the gland was at rest. The enzyme activity did not increase when secretin was added to the perfusing fluid, but when acetylcholine or pancreozymin was added, the activity rose about fourfold.6. These results are discussed in relation to the theory that plasma kinins play a prominent role in the functional vasodilatation of glandular tissues.