Factors influencing the intestinal phase of pancreatic exocrine secretion in the turkey

The present study was done to investigate the factors regulating the intestinal phase of exocrine pancreatic secretion in the turkey. The intestine of turkeys equipped with pancreatic fistulas was perfused with peptone solution, fat emulsion and hydrochloric acid (HCl), and pancreatic flow and protein output were measured. Neither peptone solution nor fat emulsion had any effects on pancreatic secretion. HCl enhanced the flow rate of pancreatic juice but not protein output. To clarify the neural mechanism of this phenomenon, the vagal postganglionic blocker atropine was continuously infused and pancreatic secretion in response to intestinal HCl was measured. Atropine completely suppressed both pancreatic flow and protein output. It is suggested that the avian intestinal phase of pancreatic secretion is mainly controlled by cholinergic action though HCl stimulation.     

Influence of dietary lactose on the development of lactase activity in the digestive tract of the pig]

Lactase activity has been measured in the pancreas, the small and large intestine of 79 pigs varying in age from 6-7 months. The endogenous enzyme level fluctuated along the small intestine but the activity did not vary according to the level of lactose fed in the diet either just after weaning or from 25 to 100 kg of live weight. Measurements performed in the content of the intestine showed that lactose could be digested by the enzymes of the microflora mostly active in the ileum, the caecum and the large intestine.     

Composition and functional role of the mucus layers in the intestine

In discussions on intestinal protection, the protective capacity of mucus has not been very much considered. The progress in the last years in understanding the molecular nature of mucins, the main building blocks of mucus, has, however, changed this. The intestinal enterocytes have their apical surfaces covered by transmembrane mucins and the whole intestinal surface is further covered by mucus, built around the gel-forming mucin MUC2. The mucus of the small intestine has only one layer, whereas the large intestine has a two-layered mucus where the inner, attached layer has a protective function for the intestine, as it is impermeable to the luminal bacteria.     

The function of the intestine in the pulmonate mollusc Helix pomatia L.

Summary Everted sacs of intestine from Helix pomatia do not actively transfer glucose, galatose, methionine, alanine, asparagine, aspartic acid or proline from the mucosal to serosal surfaces. The principal function of the intestine appears to be the reabsorption of water.The study was partly financed through a Reading University Research Board Scholarship. I thank Profs A. Graham, K. Simkiss, J. Machin and Dr C. Kyriakides for their advice and criticisms and E. Snowden and J. Counden for technical assistance.     

Relation of the character of capacitance vessel responses in spleen and small intestine elicited by electrical stimulation of the sympathetic fibres to the level of oxygen exchange in the organs

Summary There is a correlation between character and magnitude of capacitance vessel responses and venous blood oxygen saturation under electrical stimulation of sympathetic fibres in the spleen and small intestine.     

Identification of chicken lysozyme <Emphasis Type="Italic">g</Emphasis>2 and its expression in the intestine

Lysozyme is an important component of the innate immune system, protecting the gastrointestinal tract from infection. The aim of the present study was to determine if lysozyme is expressed in the chicken (Gallus gallus) intestine and to characterise the molecular forms expressed. Immunohistochemical staining localised lysozyme to epithelial cells of the villous epithelium along the length of the small intestine. There was no evidence for lysozyme expression in crypt epithelium and no evidence for Paneth cells. Immunoblots of chicken intestinal protein revealed three proteins: a 14-kDa band consistent with lysozyme c, and two additional bands of approximately 21 and 23 kDa, the latter consistent with lysozyme g. RT-PCR analyses confirmed that lysozyme c mRNA is expressed in 4-day, but not older chicken intestine and lysozyme g in 4- to 35-day chicken intestine. A novel chicken lysozyme g2 gene was identified by in silico analyses and mRNA for this lysozyme g2 was identified in the intestine from chickens of all ages. Chicken lysozyme g2 shows similarity with fish lysozyme g, including the absence of a signal peptide and cysteines involved in disulphide bond formation of the mammalian and bird lysozyme g proteins. Analyses using SecretomeP predict that chicken lysozyme g2 may be secreted by the non-classical secretory pathway. We conclude that lysozyme is expressed in the chicken small intestine by villous enterocytes. Lysozyme c, lysozyme g and g2 may fulfil complimentary roles in protecting the intestine.Received 4 August 2004; received after revision 1 September 2004; accepted 7 September 2004     

Acid and alkaline phosphatase heterogeneity in liver,heart and intestine of the adult chick

Summary The molecular heterogeneity of acid and alkaline phosphatase from chick liver, intestine and heart is demonstrated by polyacrilamide disc gel electrophoresis. Liver and heart show the same number of molecular forms of acid and alkaline phosphatases. In contrast, the intestine homogenate shows electrophoretic bands different in number and in gel position from those of the liver and of the heart.     

Is there a functional large intestine in the ferret?

Summary The intestine of the ferret (Putorius furo) is unusual in that there is no external anatomical division between ileum and colon. Up to 8–10 cm from the anus the electrical activity was organized into migrating myoelectric complexes typical of the small intestine. At this point the pattern of electrical activity changed abruptly to that characteristic of the colon, namely short and long spike burst activity. Histological examination showed that at this point the muscular layers were interupted by a band of connective tissue sufficient to permit the functional autonomy of the last part of the intestine.Acknowledgments. The authors are grateful to V. Rayner for helpful discussion and criticism. They acknowledge financial support received from INRA (Department of Veterinary Research).     

Effect of chronic hypo and hypervitaminosis C on the brush border enzymes and the intestinal uptake of glucose and alanine

Summary Brush border sucrase and alkaline phosphatase activities are considerably enhanced in the intestine of ascorbic acid deficient guinea-pigs. Similar increase in the uptake of D-glucose and L-alanine also occurs in chronic vitamin C deficiency. However the permeability of D-glucose and L-alanine in the intestine of animals fed with large doses of vitamin C is severely depressed, with a reduction in the levels of sucrase and alkaline phosphatase activities.     

The effects of lesions in several zones of the brain on cell multiplication in the glandular epithelium of the rat small intestine]

Radio-frequency lesions of tubero-infundibular region of the hypothalamus are followed by a significant increase of the mitotic rate in the small intestine glandular epithelium in rats. This increase does not occur when radio-frequency lesions are located in the anterior and posterior hypothalamus, in the dorsomedial thalamus and in the cerebral hemispheres.     

Effect of chronic hypo and hypervitaminosis C on the brush border enzymes and the intestinal uptake of glucose and alanine.

Brush border sucrase and alkaline phosphatase activities are considerably enhanced in the intestine of ascorbic acid deficient guinea-pigs. Similar increase in the uptake of D-glucose and L-alanine also occurs in chronic vitamin C deficiency. However the permeability of D-glucose and L-alanine in the intestine of animals fed with large doses of vitamin C is severely depressed, with a reduction in the levels of sucrase and alkaline phosphatase activities.     

Direct evidence favouring the notion that erythropoietin alters iron transport across the isolated intestinal tract of the rat.

A simple and reproducible method, using the isolated not everted intestine of the rat, for the study of iron transport is presented. Erythropoietin (ESF) enhanced significantly the passage of 59Fe across the intestine augmenting its movement at mucosal and serosal layers of the intestinal well.     

Evidence of major role of the intestine in cholesterol synthesis in the adult male rat.

By an new in vivo method using 1-14-C-acetate, it becomes apparent that the intestine is the main organ concerned in cholesterol synthesis. The liver contributes a mere 13.5% to the total. These results challenge the traditional theory which considers the liver as responsible for producing most of cholesterol synthesized by the rat.     

Mitotic activity in the glandular epithelium of the rat small intestine after electrothermocoagulation of the tubero-infundibular region of the hypothalamus and simultaneous resection of the pineal gland]

Radio-frequency lesions of the tubero-infundibular region of the hypothalamus and simultaneous pinealectomy are performed in rats. The double operation is followed by a significant increase of mitotic rate in the small intestine glandular epithelium. This increase is higher than the addition of the effects that are caused by each operation.     

Interaction between sugars and amino acids in intestinal absorption by rat, in vivo.

The inhibitory action of L-leucine on the intestinal absorption of D-glucose and D-galactose, as well as the inhibitory action of D-galactose on the absorption of L-leucine at various concentrations by rat small intestine has been studied. The further effect was more clearly evidenced when the medium was perfunded through the intestine in a closed circuit system using a peristaltic pump.     

Intraluminal bile salt increases rate of firing in afferent fibers from the small intestine of the rat

Perfusion of a rat intestinal segment with a solution containing sodium deoxycholate (8 mM) increases the rate of firing in periarterial afferent nerves from the gut. This observation indirectly supports our earlier proposal that bile salt evokes a net fluid secretion in the small intestine via an activation of the enteric nervous system.     

A reappraisal of the hormonal regulation of larval fat body histolysis in femaleDrosophila melanogaster

The histolysis of larval fat body cells in adult femaleDrosophila melanogaster was examined in wild type and mutant animals. The fat body cells of wild type (Canton-S),apterous ^56f homozygotes,apterous ^78jts homozygotes and heterozygotes,apterous ⁴/+, ecdysoneless¹ homozygotes and heterozygotes all underwent histolysis normally during the 72 h following adult eclosion. Only in the case ofap ⁴/ap⁴ adults did the cells fail to histolyze normally. The fat body cells of both diapausing and non-diapausing wild type females underwent histolysis at the same rate. Attempts to demonstrate histolysis in vitro were unsuccessful, even in the presence of juvenile hormones (JHs), larval ring glands, or adult ovaries. In all strains other than theap ⁴ homozygotes, a significant proportion of larval fat body cells were dead at any time while theap ⁴/ap⁴ animals, almost all cells remained viable. It is postulated that fat body cell lysis following eclosion is not a JH-mediated event, but is elicited by an as yet unidentified factor(s), possibly originating in the ovary.     

Differentiation of the endodermal epithelium associated with the splanchnic mesoderm]

Allantoic epithelium and epithelium from different levels of the digestive tube of the guail embryo were grafted into chick embryo splanchnopleure so that these epitheliums would come into contact with the mesoderm of the developing host digestive tube at a variety of levels. Under these conditions, the allantoic epithelium develops into an epithelium corresponding to the level of the digestive tube at which it was grafted. By contrast, the presumptive fate of epithelium from the small intestine is not modified by the mesenchyme with which it becomes associated. Mesenchyme from the small intestine, on the other hand, always dictates the type of differentiation in epithelial grafts from other levels of the digestive tube.     

Cyclic AMP and control of ion exchanges in the fish intestine]

In isolated intestine of the European Flounder, cyclic AMP and theophylline induce a reduction of the negative transmural potential difference and short circuit current, increase severalfold the passive permeability for chloride and abolish the active transport of this ion. These effects are very different from those described in mammals.     

Effects of cortisone and thyroxine on intestinal trehalase activity in infant mouse.

Cortisone acetate (25 microgram/g b.wt/day) administration to 8-day-old suckling mice induces a premature increase of trehalase activity along the entire small intestine. On the other hand, thyroxine (1 microgram/g b.wt/day) in unable to provoke a precocious increase of trehalase activity. Trehalase appears to be the only brush border membrane disaccharidase controlled solely by glucocorticoid hormones during the postnatal maturation of the intestine.