The rôle of the liver in pancreatic secretion.

Abstract

Secretin, when injected into dogs under amytal or ether anesthesia, proved far less effective in exciting the pancreatic flow when introduced by the portal vein than when administered by way of the femoral vein, thus confirming an earlier observation. 1 It was likewise found that with extremely potent secretin solutions, the difference in effect by the portal and systemic routes is much less marked than with weaker preparations.

In view of the fact that the secretin when injected by the portal system must first pass through the liver, it may be suggested that this organ in some way is responsible for the different behavior noted above. In order to further investigate this, secretin solutions were injected at a slow rate over a long period of time by each of these routes. When injected at the rate of one-half cubic centimeter per minute by the femoral vein, an increased secretion of the pancreatic juice was noted in the first five minute period and a constant maximum response was reached in the third five minute period. On injection of the same secretin preparation at the same rate by the portal vein, no effect could be noted for thirty minutes and the constant maximum flow of the pancreatic juice was not obtained for forty minutes; however, if a second injection of secretin solution at the slow rate was made by the portal immediately following the cessation of the flow as the result of the previous slow injection, an effect on pancreatic secretion was now noted in the second five minute interval and the constant maximum flow was obtained within twenty minutes. This result would indicate that the liver is able to absorb a considerable amount of secretin; when it becomes saturated by an injection of a relatively large amount of this substance, this power of absorption is lost and the effect obtained with secretin injections by the portal more nearly simulates that obtained by the administration by a systemic vein.