scholarly journals Intestinal disaccharidase activities in the chick

1969 ◽  
Vol 112 (1) ◽  
pp. 51-59 ◽  
Author(s):  
R. C. Siddons

1. Disaccharidase activities of the small and large intestines of the chick were studied. 2. Homogenates of the small intestine readily hydrolysed maltose, sucrose and palatinose (6-O-α-d-glucopyranosyl-d-fructose), hydrolysed lactose slowly and did not hydrolyse trehalose and cellobiose. 3. Within the small intestine the disaccharidases were located mainly in the intestinal wall; the activity in the contents accounted for less than 5% of the total activity. 4. The disaccharidases were non-uniformly distributed along the small intestine, the activities being greatest in the middle section. 5. The disaccharidase activities increased with age between 1 and 43 days. 6. Homogenates of the large intestine and contents readily hydrolysed maltose, sucrose, palatinose and lactose and hydrolysed cellobiose and trehalose slowly. 7. The large-intestinal disaccharidases were located mainly in the contents. 8. Similar Km and pH optimum values were found for the maltase, sucrase and palatinase activities of the large and small intestines. 9. The lactase activity of the large intestine was markedly affected by diet and had different Km and pH values from the small intestinal lactase. 10. Low activities of intestinal disaccharidase were found in 12-day-old embryos and marked increases in the intestinal disaccharidases of the developing embryo occurred 2–3 days before hatching.

1972 ◽  
Vol 27 (1) ◽  
pp. 101-112 ◽  
Author(s):  
R. C. Siddons ◽  
Marie E. Coates

1. Maltase sucrase, palatinase (the enzyme that hydrolyses palatinose, i.e. 6-o-α-D-gluco-pyranosyl-D-fructose) and lactase activities were measured in the small and large intestines of germ-free and conventional chicks given either a diet of purified ingredients or a practical chick mash.2. With the purified diet there were no differences in body-weight or small intestinal disaccharidase activities between germ-free and conventional chicks. With the chick mash the germ-free birds were heavier and had higher total amounts of maltase, sucrase and palatinase activities in the small intestine than did their conventional controls. When disaccharidase activities were expressed in terms of body-weight there were no differences between birds in the two environments. Enzyme activities were consistently higher in the birds given chick mash.3. Inclusion of milled fibre in the purified diet did not increase the weight or disaccharidase activities of the small intestine in either environment.4. Lactase was virtually absent from the small intestine of birds in both environments and from the large intestine of germ-free birds. There was appreciable lactase activity in the large intestinal contents of conventional chicks, and it was increased by inclusion of lactose in the diet.5. When lactose was the sole source of carbohydrate the birds grew poorly but mortality rate was less among conventional compared with germ-free chicks.6. It was concluded that the presence of micro-organisms has no direct effect on disaccharidase production in the small intestine of the chick. Microbial lactase is present in the large intestine, and at least some of the products of its action can be utilized by the bird.


1971 ◽  
Vol 121 (2) ◽  
pp. 299-308 ◽  
Author(s):  
Nils-Georg Asp

1. An acid β-galactosidase, optimum pH4.0–4.5, in the human small-intestinal mucosa was separated and characterized. 2. Autolysis of mucosal homogenates at acid pH inactivated the lactase and hetero β-galactosidase; the total activity of the acid β-galactosidase was only slightly depleted, but a greater proportion of the enzyme was solubilized by this treatment. 3. Separation on a Sephadex G-200 column revealed that the acid β-galactosidase could occur in at least three different forms, probably representing monomer, dimer and octamer or polymer of the enzyme. 4. The properties of the different forms of the acid β-galactosidase were studied with regard to pH optimum, Km, rate of hydrolysis of different substrates, and sensitivity to p-chloromercuribenzoate and tris as inhibitors. All these properties were the same for the different forms of the enzyme. 5. The acid β-galactosidase hydrolyses lactose as well as hetero β-galactosides and contributes to the lactase activity of intestinal biopsies also when measured at pH 6. This enzyme may therefore be responsible for a considerable part of the residual lactase activity found in lactose-intolerant patients.


1985 ◽  
Vol 104 (2) ◽  
pp. 435-443 ◽  
Author(s):  
A. N. Janes ◽  
T. E. C. Weekes ◽  
D. G. Armstrong

SummaryTwo groups of six sheep were fed either dried-grass or ground maize-based diets for at least 4 weeks before slaughter. Samples of the small intestinal mucosa and spancreatic tissue were assayed for a-amylase, glucoamylase, maltase and oligo-l,6-glucosidase.The pancreatic tissue contained high activities of α-amylase and much lower activities of glucoamylase, maltase and oligo-1,6-glucosidase. There was no effect of diet on the specific activities of any of these enzymes in the pancreatic tissue.The activity of α-amylase adsorbed on to the mucosa of the small intestine was greatest in the proximal region of the small intestine, the activity generally declining with increasing distance away from the pylorus. There was no diet effect on the absorbed α-amylase activity.Similar patterns of distribution along the small intestine were observed for maltase, glucoamylase and oligo-1,6-glucosidase with the highest activities in t he jejunum. There was no overall effect of diet on glucoamylase or maltase specific activities and glucoamylase total activity, although the total activities of maltase and oligo-1,6-glucosidase were significantly greater for the sheep fed the ground maize-based diet (P < 0·05).It is suggested that ruminant animals may be capable of digesting large amounts of starch in the small intestine through an adaptation in the activity of the host carbohydrases.


1963 ◽  
Vol 41 (1) ◽  
pp. 2107-2121 ◽  
Author(s):  
B. M. Laws ◽  
J. H. Moore

The digestive enzymes amylase and maltase were studied in acetone-dried powders or homogenates of the pancreatic and small intestinal tissues and small intestinal contents obtained from chicks of various ages. The stability of pancreatic amylase, which was relatively low in 0.15 M sodium chloride, was increased markedly by the presence of 0.02 M barbiturate buffer. The pH optimum of pancreatic amylase (chloride-activated) was 7.0 whereas that of intestinal maltase was 6.9. High levels of pancreatic amylase activity were found in the newly-hatched chick but these levels decreased during the following 20 days and then remained constant. The contrast between the high amylase and low maltase activities in the contents of the small intestine suggested that molecules of maltose, formed by the hydrolysis of starch, were absorbed as such by the mucosal cells. It appeared that maltose could be absorbed with equal facility from all sections of the small intestine of the 10-day-old chick but in the older birds maltose absorption seemed to occur more readily from the upper small intestine than from the duodenum and lower small intestine. A modified method for the determination of maltase activity is described.


1971 ◽  
Vol 26 (2) ◽  
pp. 135-145 ◽  
Author(s):  
J. F. Hecker

1. The object was toinvestigate the importance of urea a source of ammonia in the large intestine of herbivores. Urea was present in small intestinal contents of slaughtered horses in concentrations similar to those in blood but, in the small intestine of salughtered sheep, the urea was less than in blooc.2. There was little ammonia in small intestinal contents of slaughtered horses but consider-able ammonia was present in small intestinal contents of slaughtered sheep. The ammonia in small intestinal contents of the slaughtered sheep was probably formed from urea, as ileal con-tents taken from a sheep with an ileal cannula contained considerable urea and little ammonia.3. The ammonia concentration in caecal contents of sheep was related to the concentration of urea in blood except when ileal contents were prevented from entering the caecum.4. Ileal digesta of sheep contained more free amino nitrogen than did caecal digesta.5. Ammonia was absorbed more rapidly than water from the caecum of sheep. The rate of absorption was related to the concentration of ammonia in the caecum.


2018 ◽  
Vol 11 (4) ◽  
pp. 268-274
Author(s):  
Irina Yuryevna Karpova ◽  
Vyacheslav Vladimirovich Parshikov ◽  
Natalia Nikolaevna Prodanets ◽  
Tatyana Ivanovna Solovieva ◽  
Evgenia Dmitrievna Pyatova ◽  
...  

Based on the analysis of morphological and morphometric data, the clinical and experimental results of the effect of hypoxia on the wall of the small and large intestine in newborns are presented. The clinical part is based on the study of 58 case histories of patients with necrotizing enterocolitis, which the operating material (resected sections of the small intestine, large intestine) was studied in detail. The experimental work included the modeling of chronic hypobaric hypoxia in different trimesters of pregnancy in 4 groups of white rats (24 females). The offspring was taken out of the experiment at 4-5 days after birth, followed by collection of the small and large intestine areas to study histoarchitectonics. It is proved that hypoxia affects the number of newborn offspring, its weight. The small intestine is most vulnerable to the effect of this factor. Analysis of the morphological and morphometric picture of the operating and experimental material convincingly proves that under the influence of hypoxia the destruction of the intestinal mucosa occurs and the growth of the connective tissue component in the muscle layer occurs. Changes from the microcirculation of blood and lymph provoke the development of pre-ulcerative, ulcerative defects and the formation of necrosis. Disturbance of the drainage function promotes the spread of destruction in the intestinal wall.


2020 ◽  
Vol 318 (1) ◽  
pp. G99-G108 ◽  
Author(s):  
Marcello Costa ◽  
Timothy James Hibberd ◽  
Lauren J. Keightley ◽  
Lukasz Wiklendt ◽  
John W. Arkwright ◽  
...  

Cyclical propagating waves of muscle contraction have been recorded in isolated small intestine or colon, referred to here as motor complexes (MCs). Small intestinal and colonic MCs are neurogenic, occur at similar frequencies, and propagate orally or aborally. Whether they can be coordinated between the different gut regions is unclear. Motor behavior of whole length mouse intestines, from duodenum to terminal rectum, was recorded by intraluminal multisensor catheter. Small intestinal MCs were recorded in 27/30 preparations, and colonic MCs were recorded in all preparations ( n = 30) with similar frequencies (0.54 ± 0.03 and 0.58 ± 0.02 counts/min, respectively). MCs propagated across the ileo-colonic junction in 10/30 preparations, forming “full intestine” MCs. The cholinesterase inhibitor physostigmine increased the probability of a full intestine MC but had no significant effect on frequency, speed, or direction. Nitric oxide synthesis blockade by Nω-nitro-l-arginine, after physostigmine, increased MC frequency in small intestine only. Hyoscine-resistant MCs were recorded in the colon but not small intestine ( n = 5). All MCs were abolished by hexamethonium ( n = 18) or tetrodotoxin ( n = 2). The enteric neural mechanism required for motor complexes is present along the full length of both the small and large intestine. In some cases, colonic MCs can be initiated in the distal colon and propagate through the ileo-colonic junction, all the way to duodenum. In conclusion, the ileo-colonic junction provides functional neural continuity for propagating motor activity that originates in the small or large intestine. NEW & NOTEWORTHY Intraluminal manometric recordings revealed motor complexes can propagate antegradely or retrogradely across the ileo-colonic junction, spanning the entire small and large intestines. The fundamental enteric neural mechanism(s) underlying cyclic motor complexes exists throughout the length of the small and large intestine.


2020 ◽  
Vol 88 (6) ◽  
Author(s):  
Zhi Huo ◽  
Conghui He ◽  
Ying Xu ◽  
Tianjun Jia ◽  
Jie Wang ◽  
...  

ABSTRACT The cryptic plasmid pCM is critical for chlamydial colonization in the gastrointestinal tract. Nevertheless, orally inoculated plasmid-free Chlamydia sp. was still able to colonize the gut. Surprisingly, orally inoculated Chlamydia sp. deficient in only plasmid-encoded pGP3 was no longer able to colonize the gut. A comparison of live organism recoveries from individual gastrointestinal tissues revealed that pGP3-deficient Chlamydia sp. survived significantly better than plasmid-free Chlamydia sp. in small intestinal tissues. However, the small intestinal pGP3-deficient Chlamydia sp. failed to reach the large intestine, explaining the lack of live pGP3-deficient Chlamydia sp. in rectal swabs following an oral inoculation. Interestingly, pGP3-deficient Chlamydia sp. was able to colonize the colon following an intracolon inoculation, suggesting that pGP3-deficient Chlamydia sp. might be prevented from spreading from the small intestine to the large intestine. This hypothesis is supported by the finding that following an intrajejunal inoculation that bypasses the gastric barrier, pGP3-deficient Chlamydia sp. still failed to reach the large intestine, although similarly inoculated plasmid-free Chlamydia sp. was able to do so. Interestingly, when both types of organisms were intrajejunally coinoculated into the same mouse small intestine, plasmid-free Chlamydia sp. was no longer able to spread to the large intestine, suggesting that pGP3-deficient Chlamydia sp. might be able to activate an intestinal resistance for regulating Chlamydia sp. spreading. Thus, the current study has not only provided evidence for reconciling a previously identified conflicting phenotype but also revealed a potential intestinal resistance to chlamydial spreading. Efforts are under way to further define the mechanism of the putative intestinal resistance.


2008 ◽  
Vol 295 (3) ◽  
pp. G605-G613 ◽  
Author(s):  
S. Lukovac ◽  
E. L. Los ◽  
F. Stellaard ◽  
E. H. H. M. Rings ◽  
H. J. Verkade

Essential fatty acid (EFA) deficiency in mice induces fat malabsorption. We previously reported indications that the underlying mechanism is located at the level of the intestinal mucosa. We have investigated the effects of EFA deficiency on small intestinal morphology and function. Mice were fed an EFA-deficient or control diet for 8 wk. A 72-h fat balance, the EFA status, and small intestinal histology were determined. Carbohydrate absorptive and digestive capacities were assessed by stable isotope methodology after administration of [U-13C]glucose and [1-13C]lactose. The mRNA expression and enzyme activity of lactase, and concentrations of the EFA linoleic acid (LA) were measured in small intestinal mucosa. Mice fed the EFA-deficient diet were markedly EFA-deficient with a profound fat malabsorption. EFA deficiency did not affect the histology or proliferative capacity of the small intestine. Blood [13C6]glucose appearance and disappearance were similar in both groups, indicating unaffected monosaccharide absorption. In contrast, blood appearance of [13C]glucose, originating from [1-13C]lactose, was delayed in EFA-deficient mice. EFA deficiency profoundly reduced lactase activity (−58%, P < 0.01) and mRNA expression (−55%, P < 0.01) in mid-small intestine. Both lactase activity and its mRNA expression strongly correlated with mucosal LA concentrations ( r = 0.77 and 0.79, respectively, P < 0.01). EFA deficiency in mice inhibits the capacity to digest lactose but does not affect small intestinal histology. These data underscore the observation that EFA deficiency functionally impairs the small intestine, which in part may be mediated by low LA levels in the enterocytes.


1991 ◽  
Vol 69 (1) ◽  
pp. 116-120 ◽  
Author(s):  
Alison M. Stephen

Until the 1980s, starch in the human diet was assumed to be totally degraded and absorbed in the small intestine. Several lines of evidence since then have indicated that this is not the case, including studies of factors controlling stool output, stool bulk on elemental diets, epidemiological studies of starch intakes in developed versus developing nations, and indications using breath hydrogen that fermentation takes place in the large intestine when starch is fed. Of the few direct estimations of starch escaping absorption in the small intestine that have been carried out, one has been conducted using intubation of healthy volunteers, where two different starch meals were fed and samples aspirated from the terminal ileum. This study demonstrated that 8–10% starch escaped absorption on average, with subjects varying from 2 to 20%. Hence a sizeable proportion of starch consumed daily may reach the large intestine, with important physiological consequences. Neither small intestinal transit time nor volume of flow were related to the extent of starch malabsorption in this study. However, many factors may play a role in the extent of malabsorption, and research is continuing to investigate physiological and food characteristics that may influence the digestion and absorption of starch.Key words: starch, dietary fibre, malabsorption, ileum, gastrointestinal function.


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