scholarly journals Effect of intestinal chylomicron secretory blockade on apolipoprotein synthesis in the newborn piglet

1992 ◽  
Vol 283 (1) ◽  
pp. 81-85 ◽  
Author(s):  
D D Black
Keyword(s):  
Small Intestine ◽  
Newborn Piglet ◽  
Mrna Levels ◽  
Cellular Regulation ◽  
Apo B ◽  
Normal Increase ◽  
Expected Increase

Pluronic L-81 is a hydrophobic surfactant which blocks intestinal chylomicron secretion at the pre-Golgi level without affecting triacylglycerol uptake and re-esterification. To study the effects of such blockade on apolipoprotein synthesis, newborn female piglets received 24 h intraduodenal infusions of low-triacylglycerol, or high-triacylglycerol with or without Pluronic L-81, diets, followed by determination of apolipoprotein (apo) B-48, A-I and A-IV synthesis and content and apo B and A-IV mRNA levels in the small intestine. Jejunal apo B-48 content, synthesis and mRNA levels were down-regulated below basal levels by the addition of Pluronic to the high-triacylglycerol infusion. The normal increase in apo A-I synthesis induced by triacylglycerol absorption was ablated in both jejunum and ileum, even though the expected increase in apo A-I content in jejunum still occurred. Although attenuated, the expected increase in jejunal apo A-IV synthesis and mRNA levels with triacylglycerol absorption was still present with Pluronic treatment. These results suggest very different mechanisms of cellular regulation and trafficking for the various apolipoproteins incorporated into nascent intestinal chylomicrons. Apo B may be specifically down-regulated by the chylomicron secretory blockade induced by Pluronic L-81.

scholarly journals Determination of the molecular mass of apolipoprotein B-100 A chemical approach

1986 ◽  
Vol 239 (3) ◽  
pp. 777-780 ◽  
Author(s):  
C Y Yang ◽  
F S Lee ◽  
L Chan ◽  
D A Sparrow ◽  
J T Sparrow ◽  
...  
Keyword(s):  
Molecular Mass ◽  
Apolipoprotein B ◽  
Cell Surface Receptor ◽  
Specific Cell ◽  
Apo B ◽  
Chemical Approach ◽  
Surface Receptor ◽  
Cnbr Cleavage ◽  
Specific Cell Surface

Apolipoprotein B-100 (apo B-100) is the protein ligand in low-density lipoproteins that binds to a specific cell-surface receptor. Its molecular mass has been a subject of controversy. We have determined the molecular mass of the protein by a chemical approach. After complete CNBr cleavage, the C-terminal fragment of apo B-100 was purified by reverse-phase h.p.l.c. Amino acid N- and C-terminal analyses confirm that this peptide represents the C-terminal peptide as deduced from the DNA sequence of a human apo B-100 cDNA clone. A chemically synthesized peptide was used to determine the recovery of the peptide (74.72%). On the basis of these data, the molecular mass of apo B-100 was determined to be 496.82 +/- 24.84 kDa.

scholarly journals Identifying Dominant Runoff Processes at a Regional Scale – A GIS - Based Approach

2017 ◽  
Vol 11 (2) ◽  
pp. 19-33
Author(s):  
Fagbohun Babatunde Joseph ◽  
Olabode Oluwaseun Franklin ◽  
Adebola Abiodun Olufemi
Keyword(s):  
Overland Flow ◽  
Expert Knowledge ◽  
Regional Scale ◽  
Field Investigation ◽  
Deep Percolation ◽  
Flood Prediction ◽  
Percolation Process ◽  
Least Area ◽  
Expected Increase

Abstract Identifying landscapes with similar hydrological characteristics is useful for the determination of dominant runoff process (DRP) and flood prediction. Several approaches used for DRP-mapping differ in respect to time and data requirement. Manual approaches based on field investigation and expert knowledge are time consuming and difficult to implement at regional scale. Automatic GIS-based approach on the other hand require simplification of data but are easier to implement and it is applicable on regional scale. In this study, GIS-based automated approach was used to identify the DRPs in Anambra area. The result showed that Hortonian Overland Flow (HOF) has the highest coverage of 1508.3 Km2 (33.5%) followed by Deep Percolation (DP) with coverage of 1455.3 Km2 (32.3%). Subsurface Flow (SSF) is the third dominant runoff process covering 920.6 Km2 (20.4%) while Saturated Overland Flow (SOF) covers the least area of 618.4 Km2 (13.7%) of the study area. The result reveal that considerable amount of precipitated water would be infiltrated into the subsurface through deep percolation process contributing to groundwater recharge in the study area. However, it is envisaged that HOF and SOF will continue to increase due to the continuous expansion of built-up area. With the expected increase in HOF and SOF and the change in rainfall pattern associated with perpetual problem of climate change, it is paramount that groundwater conservation practices be considered to ensure continued sustainable utilization of groundwater in the study area.

scholarly journals Phosphatidylcholine synthesis in the developing small intestine

1980 ◽  
Vol 186 (2) ◽  
pp. 399-403 ◽  
Author(s):  
P G Holtzapple ◽  
C M Starr ◽  
T Morck
Keyword(s):  
Small Intestine ◽  
Oleic Acid ◽  
Steady State ◽  
Adult Rats ◽  
Acyltransferase Activity ◽  
Acid Incorporation ◽  
Old Rats ◽  
Phosphatidylcholine Synthesis

1. Phosphatidylcholine synthesis in the foetal, newborn and adult small intestine of rats was studied by determination of cytidine diphosphocholine-1,2-diacylglycerocholine phosphotransferase (cholinephosphotransferase) and acyl-CoA-1-acyl-sn-glycerol-3-phosphocholine acyltransferase (lysophosphatidylcholine acyltransferase) activities and the incorporation of [1-14C]oleic acid into phosphatidylcholine. 2. Cholinephosphotransferase activity was low in foetal jejunum and ileum, increased 3-4 fold in the ileum by 6 days of age and by 12 days in the jejunum. Jejunal activity remained constant throughout weaning; ileal activity gradually decreased to values 25% of that of the jejunum. 3. Lysophosphatidylcholine acyltransferase activity was high in foetal jejunum and ileum, decreased 70% immediately after birth in the jejunum and increased to adult values by 12 days of age. Ileal activity decreased by 20% after birth, but decreased more rapidly at weaning to 30% of the activity in jejunum. 4. Initial rates and steady-state incorporation of [1-14C]oleic acid into phosphatidylcholine by jejunal rings of 10 day-old rats exceeded that observed in jejunal rings from adult rats by 2-4-fold. 5. In the postnatal jejunum, neither cholinephosphotransferase and lysophosphatidylcholine acyltransferase activities nor oleic acid incorporation were stimulated by cortisone administration in vivo.

scholarly journals Experimental model for in vivo determination of dietary fibre and its effect on the absorption of nutrients in the small intestine

1981 ◽  
Vol 45 (2) ◽  
pp. 283-294 ◽  
Author(s):  
Ann-Sofie Sandberg ◽  
H. Andersson ◽  
B. Hallgren ◽  
Kristina Hasselblad ◽  
B. Isaksson ◽  
...  
Keyword(s):  
Small Intestine ◽  
Wheat Bran ◽  
Dietary Fibre ◽  
Dry Weight ◽  
Direct Analysis ◽  
Fresh Weight ◽  
Wet Weight ◽  
Definition Of

1. An experimental model for the determination of dietary fibre according to the definition of Trowell et al. (1976) is described. Food was subjected to in vivo digestion in ileostomy patients, and the ileostomy contents were collected quantitatively, the polysaccharide components of which were analysed by gas–liquid chromatography and the Klason lignin by gravimetric determination. The model was used for the determination of dietary fibre in AACC (American Association of Cereal Chemists), wheat bran and for studies on the extent of hydrolysis of wheat-bran fibre in the stomach and small intestine. The effect of wheat bran on ileostomy losses of nitrogen, starch and electrolytes was also investigated.2. Nine patients with established ileostomies were studied during two periods while on a constant low-fibre diet. In the second period 16 g AACC wheat bran/d was added to the diet. The ileostomy contents and duplicate portions of the diet were subjected to determinations of wet weight, dry weight, water content, fibre components, starch, N, sodium and potassium.3. The wet weight of ileostomy contents increased by 94 g/24 h and dry weight by 10 g/24 h after consumption of bran. The dietary fibre of AACC bran, determined as the increase in polysaccharides and lignin of ileostomy contents after consumption of bran, was 280 g/kg fresh weight (310 g/kg dry matter). Direct analysis of polysaccharides and lignin in bran gave a value of 306 g/kg fresh weight. Of the added bran hemicellulose and cellulose 80–100% and 75–100% respectively were recovered in ileostomy contents. There was no significant difference between the two periods in amount of N, starch and K found in the ileostomy contents. The Na excretion increased during the ‘bran’ period and correlated well with the wet weight of ileostomy contents.4. In conclusion, it seems probable that determination of dietary fibre by in vivo digestion in ileostomy patients comes very close to the theoretical definition of dietary fibre, as the influence of bacteria in the ileum seems small. Bacterial growth should be avoided by using a technique involving the change of ileostomy bags every 2 h and immediate deep-freezing of the ileostomy contents. True dietary fibre can be determined by direct analysis of polysaccharides and lignin in the food, at least in bran. Very little digestion of hemicellulose and cellulose from bran occurs in the stomach and small bowel. The 10–20% loss in some patients may be due to digestion by the gastric juice or to bacterial fermentation in the ileum, or both. The extra amount of faecal N after consumption of bran, reported by others, is probably produced in the large bowel.

Diabetes increases hepatic hydroxymethyl glutaryl coenzyme a reductase protein and mRNA levels in the small intestine

Metabolism ◽  
1994 ◽  
Vol 43 (4) ◽  
pp. 450-454 ◽  
Author(s):  
Kenneth R. Feingold ◽  
Dana E. Wilson ◽  
Ladonna C. Wood ◽  
Linda K. Kwong ◽  
Arthur H. Moser ◽  
...  
Keyword(s):  
Small Intestine ◽  
Coenzyme A ◽  
Mrna Levels ◽  
Coenzyme A Reductase

scholarly journals Regulation of GLUT5 gene expression in rat intestinal mucosa: regional distribution, circadian rhythm, perinatal development and effect of diabetes

1995 ◽  
Vol 309 (1) ◽  
pp. 271-277 ◽  
Author(s):  
A Castelló ◽  
A Gumá ◽  
L Sevilla ◽  
M Furriols ◽  
X Testar ◽  
...  
Keyword(s):  
Gene Expression ◽  
Small Intestine ◽  
Circadian Rhythm ◽  
Intestinal Absorption ◽  
Light Period ◽  
Proximal Jejunum ◽  
Mrna Levels ◽  
Dark Cycle ◽  
Perinatal Development ◽  
Streptozotocin Induced Diabetes

1. GLUT5 gene expression was studied in small intestine under a variety of conditions characterized by altered intestinal absorption of monosaccharides. 2. RNA-blotting studies showed that GLUT5 mRNA was abundantly expressed in rat and rabbit intestine and kidney, but it was not detected in heart or brown adipose tissue. GLUT5 mRNA levels were higher in the upper segments of the small intestine (duodenum and proximal jejunum) than in the lower segments (distal jejunum and ileum). 3. The intestinal expression of GLUT5 mRNA in rat proximal jejunum showed circadian rhythm. A 12-fold increase in GLUT5 mRNA levels was detected at the end of the light cycle and at the beginning of the dark cycle when compared with the early light period. In keeping with this, GLUT5 protein content in brush-border membranes was also increased at the beginning of the dark cycle compared with that in the light period. 4. In streptozotocin-induced diabetes an 80% increase in GLUT5 mRNA levels in mucosa from the proximal jejunum was detected under conditions in which enhanced intestinal absorption of monosaccharides has been reported. 5. The intestinal expression of GLUT5 mRNA showed regulation during perinatal development. Levels of GLUT5 mRNA were low during fetal life, increased progressively during the postnatal period and reached levels comparable with the adult state after weaning. Weaning on to a high-fat diet partially prevented the induction of GLUT5 gene expression. 6. Our results indicate that GLUT5 gene expression is tightly regulated in small intestine. Regulation involves maximal expression in the upper part of the small intestine, circadian rhythm, developmental regulation dependent on the fat and carbohydrate content in the diet at weaning and enhanced expression in streptozotocin-induced diabetes. Furthermore, changes observed in intestinal GLUT5 expression correlate with reported alterations in intestinal absorption of fructose. This suggests a regulatory role for GLUT5 in fructose uptake by absorptive enterocytes.

scholarly journals Determination of CYP450 Expression Levels in the Human Small Intestine by Mass Spectrometry-Based Targeted Proteomics

2021 ◽  
Vol 22 (23) ◽  
pp. 12791
Author(s):  
Alexia Grangeon ◽  
Valérie Clermont ◽  
Azemi Barama ◽  
Fleur Gaudette ◽  
Jacques Turgeon ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Small Intestine ◽  
Protein Expression ◽  
Mrna Levels ◽  
Targeted Proteomics ◽  
Tissue Samples ◽  
Human Organ ◽  
Expression Levels ◽  
Protein Levels ◽  
Human Small Intestine

The human small intestine can be involved in the first-pass metabolism of drugs. Under this condition, members of the CYP450 superfamily are expected to contribute to drug presystemic biotransformation. The aim of this study was to quantify protein expression levels of 16 major CYP450 isoforms in tissue obtained from nine human organ donors in seven subsections of the small intestine, i.e., duodenum (one section, N = 7 tissue samples), jejunum (three subsections (proximal, mid and distal), N = 9 tissue samples) and ileum (three subsections, (proximal, mid and distal), N = 9 tissue samples), using liquid chromatography tandem mass spectrometry (LC-MS/MS) based targeted proteomics. CYP450 absolute protein expression levels were compared to mRNA levels and enzyme activities by using established probe drugs. Proteins corresponding to seven of sixteen potential CYP450 isoforms were detected and quantified in various sections of the small intestine: CYP2C9, CYP2C19, CYP2D6, CYP2J2, CYP3A4, CYP3A5 and CYP4F2. Wide inter-subject variability was observed, especially for CYP2D6. CYP2C9 (p = 0.004) and CYP2C19 (p = 0.005) expression levels decreased along the small intestine. From the duodenum to the ileum, CYP2J2 (p = 0.001) increased, and a trend was observed for CYP3A5 (p = 0.13). CYP3A4 expression was higher in the jejunum than in the ileum (p = 0.03), while CYP4F2 expression was lower in the duodenum compared to the jejunum and the ileum (p = 0.005). CYP450 protein levels were better correlated with specific isoform activities than with mRNA levels. This study provides new data on absolute CYP450 quantification in human small intestine that could improve physiologically based pharmacokinetic models. These data could better inform drug absorption profiles while considering the regional expression of CYP450 isoforms.

scholarly journals Glutamine and cystine-enriched diets modulate aquaporins gene expression in the small intestine of piglets

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0245739
Author(s):  
Inês Vieira da Silva ◽  
Bárbara P. Soares ◽  
Catarina Pimpão ◽  
Rui M. A. Pinto ◽  
Teresa Costa ◽  
...  
Keyword(s):  
Amino Acids ◽  
Small Intestine ◽  
Amino Acid ◽  
Biochemical Parameters ◽  
Dietary Supplementation ◽  
Basal Diet ◽  
Mrna Levels ◽  
Promising Target ◽  
Dietary Treatments ◽  
Glycerol Permeability

The regulation of glycerol permeability in the gastrointestinal tract is crucial to control fat deposition, lipolysis and gluconeogenesis. Knowing that the amino acid glutamine is a physiological regulator of gluconeogenesis, whereas cystine promotes adiposity, herein we investigated the effects of dietary supplementation with glutamine and cystine on the serum biochemical parameters of piglets fed on amino acid-enriched diets, as well as on the transcriptional profile of membrane water and glycerol channels aquaporins (AQPs) in the ileum portion of the small intestine and its impact on intestinal permeability. Twenty male piglets with an initial body weight of 8.8 ± 0.89 kg were allocated to four dietary treatments (n = 5) and received, during a four week-period, a basal diet without supplementation (control) or supplemented with 8 kg/ton of glutamine (Gln), cystine (Cys) or the combination of the two amino acids in equal proportions (Gln + Cys). Most biochemical parameters were found improved in piglets fed Gln and Cys diet. mRNA levels of AQP3 were found predominant over the others. Both amino acids, individually or combined, were responsible for a consistent downregulation of AQP1, AQP7 and AQP10, without impacting on water permeability. Conversely, Cys enriched diet upregulated AQP3 enhancing basolateral membranes glycerol permeability and downregulating glycerol kinase (GK) of intestinal cells. Altogether, our data reveal that amino acids dietary supplementation can modulate intestinal AQPs expression and unveil AQP3 as a promising target for adipogenesis regulation.

Determination of the fat content in the pancreas and mucous membrane (mucosa) of the small intestine of pigs

1979 ◽  
Vol 13 (5) ◽  
pp. 546-548
Author(s):  
V. P. Pakhomov ◽  
N. N. Evgrafova ◽  
V. T. Sapleva
Keyword(s):  
Small Intestine ◽  
Mucous Membrane ◽  
Fat Content

Modified (desialylated) low-density lipoprotein measured in serum by lectin-sorbent assay

1995 ◽  
Vol 41 (7) ◽  
pp. 1018-1021 ◽  
Author(s):  
V V Tertov ◽  
I A Sobenin ◽  
A N Orekhov
Keyword(s):  
Ricinus Communis ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Diagnostic Value ◽  
Cellular Level ◽  
Chromatographic Technique ◽  
Low Density ◽  
Sialic Acid Content ◽  
Apo B

Abstract Modified low-density lipoprotein (LDL) with a low sialic acid content was found in the blood of patients with coronary atherosclerosis. This desialylated lipoprotein causes lipid accumulation in arterial smooth-muscle cells and stimulates cell proliferation and production of the extracellular matrix, i.e., induces all atherogenic manifestations at the cellular level. We have developed a lectin-sorbent assay for the determination of desialylated LDL in sera. The assay is based on the binding of desialylated LDL by immobilized Ricinus communis agglutinin with subsequent measurement of lipoprotein through use of anti-apolipoprotein (apo) B antibody. The assay is sensitive to desialylated apo B concentrations as low as 5 micrograms/L. The intraassay and interassay CVs were 4.8% and 11.3%, respectively. Comparison between the lectin-sorbent assay and a lectin chromatographic technique showed a good correlation. This determination of modified desialylated LDL in human serum with high accuracy and reproducibility may help establish the diagnostic value of this lipoprotein as a risk factor of atherosclerosis.

Sign in / Sign up

Export Citation Format

Share Document