AJP - Gastrointestinal and Liver Physiology, Vol 250, Issue 1 103-G108, Copyright © 1986 by American Physiological Society
Pancreaticobiliary factors in the modulation of small intestinal enterokinase in the rat
B. M. Newman, P. C. Lee, H. Tajiri, D. R. Cooney and E. Lebenthal
Chronic pancreaticobiliary diversion was employed to study the modulation
of enterokinase in the small intestine of adult rats. Diversion resulted in
apparent trophic changes of the proximal bypassed portion of the intestinal
mucosa. An almost complete loss of mucosal enterokinase activity in the
proximal duodenum but no increase of enterokinase in the segments distal to
reentry of the common duct was found in the pancreaticobiliary-diverted
rats. The effect on the enterokinase activity in the proximal segment was
specific in that no other brush-border enzymes measured in that segment
were decreased. The decrease in enterokinase was partially prevented by
dietary supplementation with pancreatic trypsinogen and completely avoided
with the addition of a combination of bile acids and trypsinogen.
Supplementation with bile acid alone did not preserve the enterokinase
levels in the bypassed rats. The results suggested that trypsinogen is the
primary factor responsible for modulating enterokinase levels in the
proximal small intestine, with bile acids acting as a modifier.
