Raw Soybeans Stimulate Human Pancreatic Proteinase Secretion

Abstract

Intraduodenal instillation of raw soybeans stimulated pancreatic proteinase secretion in humans. Raw soybeans almost abolished the activity of chymotrypsin and severely reduced (50%) the tryptic activity. Immunoreactive tryptic and chymotryptic material simultaneously appeared in amounts 2 to 4 times basal concentrations. This increase, demonstrated with rocket immunoelectrophoresis, was begun within the first 10 min of soybean instillation. The enhanced secretion also persisted throughout the succeeding saline instillation, and it is suggested that the presence of Kunitz trypsin inhibitor contributed to this postprandial stimulation. An amidase that hydrolyzes low-molecular-weight substrates (i.e., benzoyl-arginine p-nitroanilide) was found in raw soybeans. Its low activity was not assumed to substantially bias standard trypsin assays. The increased proteinase secretion was, as previously published, not preceded by an elevated plasma cholecystokinin concentration. The raw soybeans also caused a nonparallel secretion of amylase and proteinases. Nervous, perhaps cholinergic, regulation mediates the inhibitor-stimulated proteinase secretion in humans. This stimulation yields both a general increase of proteinases and also a specific inhibitor-resistant trypsin. This is consistent with the physiologic need for proenzyme-activation in the presence of inhibitors and for restoration of the proteolytic capacity of the duodenal juice.

The elimination of meat from the diet selectively decreases pancreatic elastase secretion

“…Therefore, the decrease of pancreatic secretion could be expected. Other factors possibly influencing pancreatic secretion in vegetarians are higher consumption of soya-bean trypsin inhibitors (Folsch & Creutzfeldt, 1985;Holm et al 1992) and dietary fibre (Isaksson et al 1982;Dutta & Hlasko, 1985) and lower intake of Se (Jackson et al 2003). However, soya is commonly added to products commercially available for omnivores.…”

Optimization of air jet impingement drying of okara using response surface methodology

“…Trypsin inhibitor is the major anti-nutritional factor in the soybeans which could interfere with the digestion of proteins, and cause adverse effect on human health, such as pancreatic disease (Holm, Reseland, Thorsen, Flatmark, & Hanssen, 1992). TIA could still be significant in the okara from soymilk production (Vishwanathan, Govindaraju, Singh, & Subramanian, 2011).…”

Characteristics of digestive processes in Atlantic salmon (Salmo salar). Enzyme pH optima, chyme pH, and enzyme activities

“…Atlantic salmon and in human duodenal juice obtained as described earlier (Holm 1988;Holm et al 1992). …”