Physiological Reviews, Vol. 82, No. 1, January 2002, pp. 1-18; 10.1152/physrev.00022.2001.
Copyright ©2002 by the American Physiological Society

Conservation of Digestive Enzymes

University of California-San Francisco, San Francisco, California; State University of New York, Buffalo, New York; and Brandeis University, Waltham, Massachusetts

Rothman, Stephen, Charles Liebow, and Lois Isenman. Conservation of Digestive Enzymes. Physiol. Rev. 82: 1-18, 2002.The traditional understanding is that an entirely new complement of digestive enzymes is secreted by the pancreas into the small intestines with each meal. This is thought to be necessary because, like food itself, these enzymes are degraded during digestion. In this review we discuss experiments that bring this point of view into question. They suggest that digestive enzymes can be absorbed into blood, reaccumulated by the pancreas, and reutilized, instead of being reduced to their constituent amino acids in the intestines. This is called an enteropancreatic circulation of digestive enzymes.