Some features of intestinal absorption of intact fibrinolytic enzyme III-1 from Lumbricus rubellus.

In order to investigate whether earthworm fibrinolytic enzyme III-1 (EFE-III-1) isolated from Lumbricus rubellus is capable of transporting into blood through intestinal epithelium and keeping its biological function in circulation, we have raised an antibody against EFE-III-1. The immunological results showed that 10-15% of intact EFE-III-1 was absorbed by the intestinal epithelium with the incubation chamber method [Vilhardt and Lundin, Acta Physiol. Scand. 126 (1986) 601-607]. The enzyme could be detected in the intestinal epithelial cells by immunohistochemistry. Furthermore, immunoreactive intact EFE-III-1 was found in serum or plasma after intraperitoneal injection of rats. Approx. 10% of the full-size enzyme could transport through the intestinal epithelium. The maximum remaining activity in blood could be assayed around 60 min after the intraperitoneal injection.