Effects of dietary proteinase inhibitors from field bean (Vicia faba L.) and field-bean meal on pancreatic function in the rat

Abstract

I . Male weanling rats were fed casein diets containing 1.25, 2.5, 5.0 and 10 g/kg active or autoclaved proteinase inhibitors (PI) from field bean (Viciu faba L.), and raw-and autoclaved-field-bean meal (FBM) diets. After 7, 14 and 2 1 d on the diets pancreas weights were measured and pancreas and intestinal trypsin (EC 3.4.4.4) and chymotrypsin (EC 3.4.4.5) assayed.2. Pancreas weights increased on the raw FBM and active-PI-supplemented diets. Maximum pancreatic hypertrophy measured as the percentage increase above controls was observed after 14 d in rats fed on raw FBM. The same percentage increase in pancreas size compared with appropriate controls was obtained with rats fed casein diets supplemented with 5 g active PI/kg.3. Pancreas trypsin and chymotrypsin levels decreased with increasing dietary PI level. Similarly, lower pancreas trypsin and chymotrypsin levels were observed in rats given raw FBM.4. Intestinal trypsin and chymotrypsin increased with increasing dietary PI inclusion level. Although the magnitude of this response decreased with the period of feeding the differences in enzyme levels were still significant even after 21 d.5 . It was concluded that the PI alone in raw-FBM diets could not entirely be responsible for theenlargement of the pancreas and the excess secretion of pancreatic enzymes since in synthetic diets PI levels of five times those in FBM were required to produce responses of similar magnitude.

Nutritional significance of a rice bran concentrate with trypsin inhibitor activity.

“…In particular, standard deviations of the protease activities in the pancreases of rats fed a RBPC diet were larger than those of the other groups. The pancreatic hypertrophy as well as the growth depression have been observed by other investigators (14)(15)(16)(17). Although our present data are ambiguous for the judgement of pancreatic enlargement, the possibility that slight pancreatic hypertrophy was caused by the …”

“…However, it seems that there is such a possibility. Many workers (14)(15)(16) have reported that the growth depression is observed in animals fed a diet containing a trypsin inhibitor, even though the apparent nitrogen digestibilities are the same between the diets with a trypsin inhibitor and without the inhibitor.…”

Histological alterations to the pancreas and the intestinal tract produced by raw faba bean (Vicia faba1. minor) diets in growing chicks

“…When protease inhibitors are isolated and included in the diets of rats, physiological responses such as pancreatic hypertrophy, decreased amounts of trypsin and chymotrypsin in the pancreas, increased amounts of these enzymes in the intestine and growth depression are observed. The significantly increased pancreas relative weight seen in experiment 1 among birds fed on a diet containing 500 g/kg of RFB, is associated with the presence of antiprotease factor(s) (Abbey et al, 1979). This is corroborated by the histological examination conducted on the pancreas with alteration of acinar cells (Figs.…”

A comparison of effects of body weight and feed intake on digestion in broiler cockerels with effects of tannins

“…Pancreatic hypertrophy in birds fed on diets containing TI (Levison et al 1979), lectin (Abbey et al 1979;Grant et al 1987) or tannin (Ahmed et al 1991) has been tacitly ascribed in its entirety to the direct effect of the antinutritional substance. However, the results of the present experiment show that merely limiting the feed intake of birds fed on a tannin-free diet can result in a higher relative pancreas weight compared with those which are fed ad lib.…”