Microcirculatory dynamics in the normal and inflamed pancreas

Abstract

When an India ink solution was infused into the main pancreatic duct of the dog, the particles were shown to pass between the cells of the acinar unit without apparent ductal rupture. The ink accumulated in a well defined space immediately adjacent to the basilar aspect of the acinus. This periacinar space appeared to communicate directly with terminal ramifications of the local lymphatic circulation. When the lymphatic system was patent, an ink solution introduced into the periacinar space was removed by this route, and the ink particles were deposited in the lung. When the lymphatic system was obstructed by ligation of the thoracic duct, much of the ink remained in the periacinar spaces; however, there was also a considerable concentration of the particulate material in the liver. The latter suggested that the periacinar spaces also communicated directly with the local capillary (portal) circulation. During acute pancreatitis the periacinar spaces became acutely distended, and congestion and stasis were present in both the lymphatic and capillary components of the circulation. Ultimately, erythrocytes filled the periacinar spaces, suggesting the communications between the capillaries and periacinar spaces became pervious to both the fluid and cellular components of the blood. The latter may in part explain the development of hematochylia during acute experimental pancreatitis. The existence of a periacinar space which communicated with both the lymphatic and the capillary circulation of the pancreas was supported by the distribution of ink when it was infused directly into the local lymphatic, venous, or arterial systems during acute pancreatitis.