Abstract
The oral ingestion of naturally occurring purified trypsin inhibitors from soybean, ovomucoid, and bovine pancreas has been demonstrated to be a potent stimulus to pancreatic digestive enzyme synthesis. This effect may be so marked as to lead to impairment of growth in the rat and chicken through the faecal loss of essential amino acids. This is thought to be due to the markedly potentiated secretion of pancreatic digestive enzyme protein overwhelming the normal digestive capacity of the gastrointestinal tract and resulting in a pancreatogenous protein-losing enteropathy.
Experimental evidence is presented to suggest that this response to the trypsin inhibitors requires the mediation of the gastrointestinal tract and is independent of vagal innervation to the pancreas. The most satisfactory hypothesis would favour the release of a trophic stimulus from the intestinal mucosa (possibly pancreozymin-cholecystokinin) to the acinar cell of the pancreas in response to the presence of the trypsin inhibitor in the bowel lumen.
It is suggested that a primary function of the endogenously secreted pancreatic trypsin inhibitor may be to potentiate enzyme synthesis by the acinar cell, providing an important stimulus for the repletion of the digestive enzymes. Some of the potential physiological and clinical implications of such a mechanism are discussed.
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Selected References
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- BORCHERS R. Counteraction of the growth depression of raw soybean oil meal by amino acid supplements in weanling rats. J Nutr. 1961 Nov;75:330–334. doi: 10.1093/jn/75.3.330. [DOI] [PubMed] [Google Scholar]
- GROSSMAN M. I. Some properties of trypsin inhibitor of pancreatic juice. Proc Soc Exp Biol Med. 1958 Nov;99(2):304–306. doi: 10.3181/00379727-99-24331. [DOI] [PubMed] [Google Scholar]
- HAVERBACK B. J., DYCE B., BUNDY H., EDMONDSON H. A. Trypsin, trypsinogen and trypsin inhibitor in human pancreatic juice. Am J Med. 1960 Sep;29:421–433. doi: 10.1016/0002-9343(60)90038-3. [DOI] [PubMed] [Google Scholar]
- KALSER M. H., GROSSMAN M. I. Secretion of trypsin inhibitor in pancreatic juice. Gastroenterology. 1955 Jul;29(1):35–45. [PubMed] [Google Scholar]
- KASSELL B., RADICEVIC M., BERLOW S., PEANASKY R. J., LASKOWSKI M., Sr THE BASIC TRYPSIN INHIBITOR OF BOVINE PANCREAS. I. AN IMPROVED METHOD OF PREPARATION AND AMINO ACID COMPOSITION. J Biol Chem. 1963 Oct;238:3274–3279. [PubMed] [Google Scholar]
- Khayambashi H., Lyman R. L. Growth depression and pancreatic and intestinal changes in rats force-fed amino acid diets containing soybean trypsin inhibitor. J Nutr. 1966 Aug;89(4):455–464. doi: 10.1093/jn/89.4.455. [DOI] [PubMed] [Google Scholar]
- Klose A. A., Greaves J. D., Fevold H. L. Inadequacy of Proteolytic Enzyme Inhibition as Explanation for Growth Depression by Lima Bean Protein Fractions. Science. 1948 Jul 23;108(2795):88–89. doi: 10.1126/science.108.2795.88. [DOI] [PubMed] [Google Scholar]
- Kunitz M. CRYSTALLIZATION OF A TRYPSIN INHIBITOR FROM SOYBEAN. Science. 1945 Jun 29;101(2635):668–669. doi: 10.1126/science.101.2635.668. [DOI] [PubMed] [Google Scholar]
- LEWIS J. C., SNELL N. S., HIRSCHMANN D. J., FRAENKEL-CONRAT H. Amino acid composition of egg proteins. J Biol Chem. 1950 Sep;186(1):23–35. [PubMed] [Google Scholar]
- LYMAN R. L., LEPKOVSKY S. The effect of raw soybean meal and trypsin inhibitor diets on pancreatic enzyme secretion in the rat. J Nutr. 1957 Jun 10;62(2):269–284. doi: 10.1093/jn/62.2.269. [DOI] [PubMed] [Google Scholar]
- LYMAN R. L. The effect of raw soybean meal and trypsin inhibitor diets on the intestinal and pancreatic nitrogen in the rat. J Nutr. 1957 Jun 10;62(2):285–294. doi: 10.1093/jn/62.2.285. [DOI] [PubMed] [Google Scholar]
- LYMAN R. L., WILCOX S. S., MONSEN E. R. Pancreatic enzyme secretion produced in the rat by trypsin inhibitors. Am J Physiol. 1962 Jun;202:1077–1082. doi: 10.1152/ajplegacy.1962.202.6.1077. [DOI] [PubMed] [Google Scholar]
- Lepkovsky S., Koike T., Sugiura M., Dimick M. K., Furuta F. Pancreatic amylase in chickens fed on soya-bean diets. Br J Nutr. 1966;20(3):421–437. doi: 10.1079/bjn19660044. [DOI] [PubMed] [Google Scholar]
- Melnick D., Oser B. L., Weiss S. Rate of Enzymic Digestion of Proteins as a Factor in Nutrition. Science. 1946 Mar 15;103(2672):326–329. doi: 10.1126/science.103.2672.326-a. [DOI] [PubMed] [Google Scholar]
- Ozawa K., Laskowski M., Jr The reactive site of trypsin inhibitors. J Biol Chem. 1966 Sep 10;241(17):3955–3961. [PubMed] [Google Scholar]
- Rothman S. S., Wells H. Enhancement of pancreatic enzyme synthesis by pancreozymin. Am J Physiol. 1967 Jul;213(1):215–218. doi: 10.1152/ajplegacy.1967.213.1.215. [DOI] [PubMed] [Google Scholar]
- Salman A. J., Pubols M. H., McGinnis J. Chemical and microscopic nature of pancreata from chicks fed unheated soybean meal. Proc Soc Exp Biol Med. 1968 May;128(1):258–261. doi: 10.3181/00379727-128-32991. [DOI] [PubMed] [Google Scholar]
- Sambeth W., Nesheim M. C., Serafin J. A. Separation of soybean whey into fractions with different biological activities for chicks and rats. J Nutr. 1967 Aug;92(4):479–490. doi: 10.1093/jn/92.4.479. [DOI] [PubMed] [Google Scholar]
- Siegel B., Jacobs R., Studer R., Potchen E. J. Attempts to augment pancreatic selenomethionine uptake: effect of raw soybean diet. J Lab Clin Med. 1968 Jun;71(6):945–947. [PubMed] [Google Scholar]
- WU Y. V., SCHERAGA H. A. Studies of soybean trypsin inhibitor. I. Physicochemical properties. Biochemistry. 1962 Jul;1:698–705. doi: 10.1021/bi00910a025. [DOI] [PubMed] [Google Scholar]
- Webster P. D., 3rd Early effect of methacholine on pancreatic RNA synthesis. Am J Physiol. 1968 Apr;214(4):851–855. doi: 10.1152/ajplegacy.1968.214.4.851. [DOI] [PubMed] [Google Scholar]
