Conservation of digestive enzymes.

@article{Rothman2002ConservationOD,
  title={Conservation of digestive enzymes.},
  author={Stephen S. Rothman and Charles Liebow and Lois Isenman},
  journal={Physiological reviews},
  year={2002},
  volume={82 1},
  pages={
          1-18
        }
}
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… 
View on PubMed
jpck.zju.edu.cn
68 Citations
Highly Influential Citations
1
Background Citations
22
Methods Citations
1
Results Citations
1

Figures and Tables from this paper

68 Citations

The activity of pancreatic enzymes on different stages of metabolism in broiler chicks

The physiological investigation showed that complex-reflex regulatory phase of pancreatic secretion continues during 120 min after feeding with the subsequent transition to neurohumoral phase (mediated by secretion of hormones secretin and cholecystokinine into the blood stream) when chymus reaches the intestine.

Making Sense of Digestive Enzymes

The importance of enzymes in helping to maintain optimal health has yet to be as widely acknowledged as that of other micronutrients, but research documenting their benefits continues to mount.

Hydrolases of the digestive glands in human sweat

The sweat eccrine and apocrine glands of human skin secrete many functionally significant substances, including hydrolytic enzymes, onto its surface through the mechanisms of secretion, excretion and…

The activity of trypsin in the pancreatic juice and blood of poultry increases simultaneously in the postprandial period

It is concluded that after overnight fasting the increase of trypsin activity in pancreatic juice and blood serum in the postprandial period occurs in parallel, which determines not only digestion of food protein but also the level of metabolism.

Mechanisms of Regulation for Serine Protease Activity in the Rat Ileocecal Junction

Reverse zymography results suggest that a previously unknown inhibitor of about 30 kDa for trypsin may be present in the cecal wall but absent in the small or large intestinal homogenates, and mass spectroscopy results suggest an immunoglobulin heavy chain antibody may be the source of the unknown inhibitor.

Are intact peptides absorbed from the healthy gut in the adult human?

It is concluded that there is little unequivocal evidence that dietary bioactive peptides, other than di- and tripeptides, can cross the gut wall intact and enter the hepatic portal system in physiologically relevant concentrations.

The Correlation between the Activities of Digestive Enzymes in the Pancreas and Blood Serum in Chicken

The strong positive correlation between tryptic activities in the pancreas or pancreatic juice and in blood serum in chicken can be a starting point for further research on the functions of circulatory trypsin which can include the regulation of exocrine pancreatic activity and other vital functions.

General Principles of Gastrointestinal Function — Motility , Nervous Control , and Blood Circulation

  • Medicine
  • 2015

Role of pancreatic enzymes in the development of multiple organ failure after shock

The literature surrounding the hypothesis that digestive enzymes produced by the pancreas are involved in the initiation of the systemic inflammatory response after shock and, ultimately, contribute to multiorgan failure and death is reviewed.

Effects of Exogenous Multi-enzyme Feed Additive (Kemzyme) on the Activities of Certain Digestive Enzymes and Intestinal Morphology in Growing Rabbits

It was obvious that the higher growth rate in kemzyme-supplemented rabbits was associated with improved digestive enzymatic activities and intestinal morphology, and it seemed that the exogenous enzymes did not get affected by the endogenous proteolytic activity of the gastro intestinal tract.
...

References

SHOWING 1-10 OF 175 REFERENCES

Enteropancreatic circulation of digestive enzymes.

The pancreas appears to be able to recycle proteins much as the liver recycles bile salts, although the magnitude of this process remains uncertain.

Enteropancreatic circulation of digestive enzyme as a conservation mechanism

The experiments reported here are consistent with this latter view and suggest the circulation of approximately 60% of a mixture of digestive enzymes instilled into the duodenum (82–92% at steady state).

Distribution and fate of pancreatic enzymes in small intestine of the rat.

Diversion of pancreatic juice to the exterior of the body resulted in rapid disappearance of enzymes from the small intestine with virtually complete absence after 16 hr.

Enteropancreatic circulation of digestive enzymes does not exist in the rat

The hypothesis of an enteropancreatic circulation1–3, that digestive enzymes are absorbed intact across the intestinal epithelium, are circulated through the bloodstream and rese-creted by the…

The endocrine secretion of mammalian digestive enzymes by exocrine glands.

A variety of evidence suggests that the endocrine secretion of digestive enzymes is a normal occurrence that can be of substantial magnitude in healthy individuals, is responsive to various physiological stimuli, and is distinct from exocrine secretion.

Absorption of exogenous and endogenousproteolytic enzymes

The method described does not seem to be useful as a pancreatic function test because it indicates absorption of the enzymes administered rather than release of secondary enzymes from the intestinal tract.

Permeability of adolescent rat intestine to pancreatic ribonuclease.

The experimental data favor simple diffusion of RNase across rat small bowel, but the amounts of pancreatic RNase absorbed were small, and while the data do not negate the concept of an enteropancreatic recirculation in the rat, only a minor quantity of luminal, pancreaticRNase could recirculate.

The characterization of rat intestinal amylase.

The physiology of secretin.

Effect of feeding on the protein synthesis in mammalian pancreas.

...