The aims of the present study were: 1) to describe the changes in the absorption of free oleic and palmitic acids in young chicks during the first two weeks after hatching; 2) to find out if yolk sac ablation induces any change in the absorbability of such fatty acids. The study was carried out in normal and yolk-sac-ablated broiler chicks aged 2, 8 and 13 days. 14C-labelled oleic and palmitic acids were given p.o. in suspension. Stools were collected for 48h and the recovery of radioactivity was determined and considered as an indicator of the extent of absorption. Our results indicate that the absorption of palmitic acid decreased with age (p less than 0.05) whereas the absorption of oleic acid increased significantly (p less than 0.005). The changes in the absorptive capacity for each fatty acid occurred during the first week. The absorption of both fatty acids was greater in yolk-sac-ablated chicks (p less than 0.05). The relative contents of different fatty acids in yolk lipids was investigated. The results clearly indicate that the ratio OA/PA linearly increased from hatching until the 4th day. Thus the possibility that yolk sac lipids passing to the intestine through the yolk stalk are able to modify the absorptive processes cannot be excluded.

Aging↗

PubMedDate not supplied

Functional consequences of chronic implantation of electrodes for electromyographic studies in the gastrointestinal tract of chickens.

The aims of this work were: A) to define the morphological and functional changes induced by chronic implantation of electrodes for electromyographic studies and B) to study the evolution of the gastrointestinal myoelectrical activity after electrode implantation. Four lots of animals were established: birds implanted with 7 and 5 triplets of electrodes in the gastroduodenal area (lots I5 and I7 respectively); sham operated birds (lot SH) and control (lot C). Body weight was not modified by surgery. Food intake, which was transiently decreased, returned to normal within the first week post-implantation. Gastrointestinal transit time (TT) was significantly increased in lots I7 and SH during the first week. In SH birds TT returned to normal in the second week after surgery, whereas in I7 birds this parameter was not normalized until the third week. Apparent hypertrophy of the duodenum was found in lot I7 but not in lots SH and C (P < 0.05). Qualitative electromyographical changes were found in lot I7 but not in lot I5, with no morphological changes. The evolution of the electrical signal (frequency and amplitude of spiking) was analyzed in lot I5. Frequency stabilized shortly after surgery (0.8-2 days). In contrast, amplitude increased progressively to reach a steady value 9-18 days after surgery. Our results indicate that the number of electrodes implanted for electromyographical studies may induce significant morphological as well as motor changes in the gastrointestinal tract. Thus there should be as few electrodes as possible in order to avoid the changes mentioned above.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMedDate not supplied

Experimental conditions affecting in vitro intestinal incorporation of palmitic acid: a methodological approach.

In the rat, a large number of in vitro studies on intestinal fatty acid uptake have been carried out. However, the results obtained under different experimental conditions are often contradictory. The present work is a critical approach to the experimental aspects which may modify in vitro intestinal uptake of fatty acids. Different kinds of intestinal tissue samples (intact, everted or opened rings) were used. The histological changes and the uptake of palmitic acid were measured for each type of sample under different stirring rates, at different incubation times and with micellar solutions of varying composition. It is concluded that 1) opened rings have the highest absorptive capacity with the lowest dispersion; 2) incubation periods longer than 30 minutes do not result in additional palmitic acid uptake and may lead to severe tissue hypoxia as indicated by extensive vacuolization; 3) stirring rates over 1 cycle/sec do not result in increased PA uptake and cause extensive mucosal disruption, particularly in jejunal samples.

Animals↗

PubMedDate not supplied

Effects of oleic and elaidic acids on in vitro intestinal uptake of cholesterol in the rat.

The effects of oleic and elaidic acid upon the in vitro intestinal uptake of cholesterol were studied in 9 weeks-old male and female rats. Elaidic acid increases the uptake of cholesterol when compared to oleic acid in both males and females. It is suggested that elaidic acid may enhance the esterification of cholesterol within the enterocyte through being more available for esterification and/or through being preferentially incorporated into cholesterol esters.

Animals↗

PubMedDate not supplied

Effects of temperature on in vitro palmitic acid uptake by chicken and rat intestinal tissue.

The intestinal absorption of fatty acids proceeds by simple or facilitated diffusion, a mechanism which is affected by temperature. However, most studies in this field have not taken into consideration the fact that birds have higher physiological temperature than mammals, the absorption being studied at 37 degrees C in both cases. The aim of this work has been to find out whether the higher palmitic acid (PA) uptake rate in birds (chickens) compared to mammals (rats) is attributable to the differences between their body temperatures (41.5 degrees C for chickens and 37.5 degrees C for rats). PA-uptake was studied in intestinal (ileal and jejunal) tissue samples of both Hybro broiler chickens (male and female, 4 weeks-old) and Ico:OFA rats (males and females, 8 weeks-old). The intestinal tissue samples were incubated in micellar solution (0.6 mM 14C-PA; 0.3 mM monoolein; 3.4 mM sodium taurodeoxycholate) at 37.5 degrees C and 41.5 degrees C in both cases. Chicken intestinal tissue incorporated PA with higher efficiency at 41.5 degrees C than at 37.5 degrees C. In contrast, increasing the incubation temperature to 41.5 degrees C led to a decrease in PA uptake by female rat intestinal tissue whereas specimens from male rats exhibited the same absorptive efficiency. These results suggest that the incubation temperature determines to some extent the efficiency of fatty acid uptake. However the fact that the temperature caused opposite effects in rats and chickens indicates that the changes in temperature affect the intracellular processing of the fatty acids already taken up rather than the diffusion of fatty acids through the enterocyte brush-border membrane.

Animals↗