Intestinal transepithelial transport constitutes a major limiting step in the transfer of food protein antigens to the blood. This transport was studied in isolated rabbit ileum in Ussing chamber in vitro for the milk protein antigen beta-lactoglobulin (beta-Lg). The transepithelial passage of beta-Lg was measured by enzyme-linked immunosorbent assay (ELISA) and radiolabeled protein transfer and compared with that of the nonmetabolizable marker polyethylene glycol (PEG)-4000. When 1 mg/ml of beta-[14C]Lg or [3H]PEG was added to the mucosal side of the tissue, the total uptake, measured as the transfer of radiolabeled material across the ileum, was significantly higher for beta-Lg than for PEG (5.46 +/- 1.75 vs. 1.43 +/- 0.26 micrograms.h-1.cm-2). Measured by ELISA, 6-9% of the total amount of beta-Lg transported was absorbed in an intact antigenic form. This transport of intact beta-Lg was inhibited by the metabolic inhibitors 50 mM 2-deoxyglucose and 1 mM azide added simultaneously, was reduced by the microtubule assembly inhibitor 0.05 mM colchicine, and was enhanced by 20 mM ammonia, which inhibits lysosomal proteolytic activity. These results indicate that beta-Lg is efficiently absorbed by the intestinal mucosa of adult animals, partly in intact antigenic form and that beta-Lg transport is probably transcellular, as observed for other proteins. The finding that beta-Lg is absorbed in intact antigenic form agrees with other reports implying that beta-Lg is the main factor responsible for milk protein immunoreactivity and intolerance.
This work was conducted in order to study the value of olive mill wastes as diet on the growth performance, abdominal and muscle fat deposition, adipose and muscle tissues fatty acid composition in broilers. 200 male chickens that were 2 weeks old, 50 for each diet, were assigned to one of the three diets containing 5, 10 or 15% olive mill wastes (OMW) compared to control diet (CD). There were no significant differences in body and weight gain, final body carcass, thighs and pectoral muscle weight between birds. The same observation was seen for abdominal tissue fat (% of body weight) of which no differences were detected in birds fed OMW diet compared to those fed on the control diet. Linoleic acid proportion increases significantly in the pectoral muscle (p < 0.0001) with the three diets containing OMW, but its level decreases in tight muscle with 5 and 10% OMW diets (p < 0.0001) and remain unchanged in abdominal fat. Oleic acid proportion increases in thigh muscle (p < 0.006) and remain unchanged in pectoral muscle and in abdominal adipose tissue. Palmitic acid proportion decreases significantly in pectoral muscle (p < 0.0001) and in abdominal adipose tissue (p < 0.002), but increases significantly in thigh muscle (p < 0.05). In conclusion, OMW diet gives attractive results. It brings identical growth performances and affect abdominal and muscle fat deposition and fatty acid composition.
Summary ― Degradations by proteolytic enzymes and intestinal epithelial permeability represent two major drawbacks to the transfer of food protein antigens to blood. These steps were studied in vitro for the milk protein antigens p-Lactogtobutin (!-Lg), a-Lactalbumin (a-La) and p-casein (!-cas). Pepsin-trypsin hydrolysis and permeability in isolated rabbit ileum in Ussing chamber were suited by ELISA and radiolabelled-protein measurement. Pepsin-trypsin hydrolysis showed an increasing resistance in the order p-cas < a-La < p-Lg.
The aim of this study in the rat was to determine the effect of a low-protein diet (3 p. 100 cereal protein) and balanced refeeding (23.5 p. 100 mixed protein) on the activity of some pancreatic digestive enzymes and the amount of their secretion. Parraliel studies were carried out on the pancreas and its exocrine secretion. 1) With a low-protein diet (21 days), there was a decrease in the amounts of bile and pancreatic juice secreted. During balanced refeeding (18 days), the amount of bile secreted returned to normal and, although that of the juice increased, it was less than the amount secreted by the reference lot. 2) Body and pancreatic weights decreased slightly with the low-protein diet. The protein content and mitotic ability of the pancreas declined. However, during balanced refeeding, the ponderal weight of the pancreas returned to normal more rapidly than that of the overall organism. Pancreatic protein content and mitotic ability also augmented. 3) The low-protein diet produced an overall decrease in enzyme activity in the pancreas and in the juice. However, in the absence of any dietary stimulation, these activities were not affected proportionally in the same way as the pancreas and its exocrine secretion. Nevertheless, no disturbance in the digestion and absorption of the ration was observed. 4) During balanced refeeding, enzyme activities increased to different levels in the juice and the pancreas but after 18 days total enzyme activity had not been entirely recovered. 5) Enzyme activity varied widely, especially during the first 48 hrs of malnutrition and the first 36 hrs of refeeding. Introduction. Protein deficiency causes serious disorders in the pancreas. It is important for pediatricians to know what ability protein-deficient children have to digest a wellbalanced diet when they are refed after protein malnutrition. Digestive enzyme activities are usually lower in the duodenal aspirates of human infants (Gomez et al., 1954 ;
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