Effect of Bile Acids and Other Factors on Cholesterol Uptake by Inverted Intestinal Sacs

1958 ◽  
Vol 195 (3) ◽  
pp. 773-778 ◽  
Author(s):  
Archie L. Smith ◽  
C. R. Treadwell
Keyword(s):  
Small Intestine ◽  
Bile Acid ◽  
Bile Acids ◽  
Binding Sites ◽  
Cellular Protein ◽  
Rat Small Intestine ◽  
Cholesterol Uptake ◽  
Quantitative Studies ◽  
Mucosal Cells ◽  
Intestinal Mucosal Cells

Conditions for the use of inverted sacs of rat small intestine for quantitative studies of cholesterol uptake are described. The uptake of cholesterol by sacs did not require glucose in the incubation medium. Albumin aided cholesterol uptake but was not obligatory for this process. A binding of cholesterol to a cellular protein is proposed as the mechanism for the entrance of cholesterol into intestinal mucosal cells. Both conjugated and unconjugated bile acids inhibited cholesterol uptake possibly by blocking the binding sites of the protein responsible for cholesterol uptake. Commercial taurocholate and glycocholate contain an inhibitor of cholesterol uptake other than the bile acid.

Activity Fronts of Migrating Myoelectric Complex: Initiation by Luminal Bile Acids in Rat Small Intestine

2008 ◽  
Vol 3 (2) ◽  
pp. 84-91 ◽  
Author(s):  
I. Nilsson ◽  
T. Svenberg ◽  
B. Wallin ◽  
G. Hedenborg ◽  
P. M. Hellström
Keyword(s):  
Small Intestine ◽  
Bile Acids ◽  
Rat Small Intestine ◽  
Migrating Myoelectric Complex

Distribution of 3α-hydroxysteroid dehydrogenase (bile acid binder) in rat small intestine: Comparison with glutathione S-transferase subunits

1994 ◽  
Vol 29 (2) ◽  
pp. 115-119 ◽  
Author(s):  
Wataru Yamamuro ◽  
Andrew Stolz ◽  
Hajime Takikawa ◽  
Motonobu Sugimoto ◽  
Neil Kaplowitz
Keyword(s):  
Small Intestine ◽  
Bile Acid ◽  
Hydroxysteroid Dehydrogenase ◽  
Rat Small Intestine ◽  
Glutathione S Transferase

Expression of ileal Na+-dependent bile acids transporter gene in transposed ileum of rat small intestine

1999 ◽  
Vol 19 (7) ◽  
pp. 1009-1016 ◽  
Author(s):  
Ryuhei Kanamoto ◽  
Kenta Kinoshita ◽  
Tomoyuki Maruyama ◽  
Thoru Seki ◽  
Kimikazu Iwami
Keyword(s):  
Small Intestine ◽  
Bile Acids ◽  
Rat Small Intestine ◽  
Transporter Gene

scholarly journals Structural basis for murine norovirus engagement of bile acids and the CD300lf receptor

2018 ◽  
Vol 115 (39) ◽  
pp. E9201-E9210 ◽  
Author(s):  
Christopher A. Nelson ◽  
Craig B. Wilen ◽  
Ya-Nan Dai ◽  
Robert C. Orchard ◽  
Arthur S. Kim ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Bile Acid ◽  
Bile Acids ◽  
Binding Sites ◽  
Structural Basis ◽  
Interface Residue ◽  
Cellular Receptor ◽  
Murine Norovirus ◽  
Bile Acid Binding ◽  
P Domain

Murine norovirus (MNoV) is closely related to human norovirus (HNoV), an infectious agent responsible for acute gastroenteritis worldwide. Here we report the X-ray crystal structure of the dimeric MNoV VP1 protruding (P) domain in complex with its cellular receptor CD300lf. CD300lf binds the P domain with a 2:2 stoichiometry, engaging a cleft between the AB and DE loops of the P2 subdomain at a site that overlaps the epitopes of neutralizing antibodies. We also identify that bile acids are cofactors enhancing MNoV cell-binding and infectivity. Structures of CD300lf–P domain in complex with glycochenodeoxycholic acid (GCDCA) and lithocholic acid (LCA) reveal two bile acid binding sites at the P domain dimer interface distant from receptor binding sites. The structural determinants for receptor and bile acid binding are supported by numerous biophysical assays utilizing interface residue mutations. We find that the monomeric affinity of CD300lf for the P domain is low and is divalent cation dependent. We have also determined the crystal structure of CD300lf in complex with phosphocholine, revealing that MNoV engages its receptor in a manner mimicking host ligands including similar metal coordination. Docking of the cocomplex structures onto a cryo-EM–derived model of MNoV suggests that each virion can make multiple CD300lf engagements, and thus, infection may be driven by the avidity of cell surface clustered CD300lf. These studies identify multiple potential modulators of norovirus infection that may act to regulate the interaction between the viral capsid P domain and its cognate cellular receptor.

scholarly journals HUMAN ORGANIC SOLUTE TRANSPORTERS UTTERED IN SMALL INTESTINE, LIVER, AND KIDNEY FOR HOMEOSTASIS

2019 ◽  
pp. 12-17
Author(s):  
HARANATH CHINTHAGINJALA ◽  
HINDUSTAN ABDUL AHAD ◽  
MAHESH REDDY CHALLA ◽  
GANDLA CHAITHANYA BARGHAV ◽  
PASAM DEVIKA ◽  
...  
Keyword(s):  
Small Intestine ◽  
Bile Acid ◽  
Drug Absorption ◽  
Binding Sites ◽  
Wide Range ◽  
Liver And Kidney ◽  
Bile Acid Transporter ◽  
Organic Solute ◽  
Drug Pharmacokinetics ◽  
Solute Transporters

The transporters participate in a significant role in drug absorption, distribution, metabolism, and elimination. Transporters are of efflux and influx type, need ATP-binding sites for their in and out movement across the cell membrane. These transporters play an important role in allowing or opposing the drugs into the cells, results in non-linearity in drug pharmacokinetics. A wide range of transporters was discovered; among them, organic solute transporters (OST) play a key role in drug absorption and disposition. Organic solute transporters is a heteromeric transporter localized to the basolateral of epithelial cells. It is the primary efflux bile acid transporter in the intestine of mammals.

Hydrolysis of peptides within lumen of small intestine

1976 ◽  
Vol 231 (5) ◽  
pp. 1322-1329 ◽  
Author(s):  
DB Silk ◽  
A Nicholson ◽  
YS Kim
Keyword(s):  
Small Intestine ◽  
Brush Border ◽  
Electrophoretic Mobilities ◽  
Chemical Assay ◽  
Intestinal Contents ◽  
Mucosal Cells ◽  
Peptide Hydrolases ◽  
Hydrolysis Of ◽  
Germfree Rats ◽  
Intestinal Mucosal Cells

The quantitative significance of intraluminal peptide hydrolases in the terminal stages of peptide digestion has been investigated, and the precise origins of these enzymes have been determined. Intestinal contents and mucosae were obtained from rats anethetized with ether. Experiments carried out on pancreaticobiliary secretions and germfree rats show that pancreatic and bacterial enzymes do not contribute significantly toward the luminal digestion of dipeptides. Chemical assay data, thermostability studies, and examination of electrophoretic mobilities of luminal peptide hydrolases indicate that jejunal enzymes originate predominantly from the cytoplasm of intestinal mucosal cells, whereas the brush border of muosal cells is a major source of the enzymes in the ileum. With glycl-L-phenylalanine and L-phenylalanyl-glycine as substrates, jejunal luminal activity was less than 2.6% of mucosal activity. Brush-border peptide hydrolase activity in ileal contents, however, was 11.9% and 40.7% of mucosal brush-border activity for the two substrates. Luminal enzymes thus play an insignifcant role in the terminal digestion of peptides in the jejunum, but have a much more important role in the ileal digestion of peptides.

scholarly journals Relationship of non-esterified fatty acids to vitamin D-dependent Ca2+ binding by rat intestinal Golgi-enriched membrane fractions

1984 ◽  
Vol 218 (2) ◽  
pp. 355-360 ◽  
Author(s):  
J R F Walters ◽  
M M Weiser
Keyword(s):  
Fatty Acids ◽  
Vitamin D ◽  
Small Intestine ◽  
Fatty Acid ◽  
Binding Sites ◽  
Close Correlation ◽  
Rat Small Intestine ◽  
Golgi Membrane ◽  
Esterified Fatty Acids ◽  
Relationship Of

Ca2+ binding and concentrations of non-esterified fatty acids and phospholipids were compared in membrane fractions of rat small intestine. These fractions differed in density and were enriched for galactosyltransferase activity, a Golgi-membrane marker. Ca2+ binding was highest in the Golgi subfraction with the least density, as were the concentrations of both non-esterified fatty acids and phospholipids; galactosyltransferase activity was distributed differently. The large amount of non-esterified fatty acids was sufficient to account for a 2:1 complex of fatty acid-Ca2+. In vitamin D-deficient animals, the yield of protein in the lightest subfractions was decreased, but Ca2+ binding per mg of protein was further decreased to about 60%. In Golgi fractions from vitamin D-deficient animals, Ca2+ binding and the concentration of non-esterified fatty acids were decreased in parallel, but phospholipids were not significantly changed. There was a close correlation between Golgi Ca2+ binding and non-esterified fatty acid concentrations (r = 0.89; P less than 0.001). Non-esterified fatty acids, which are unusually prevalent in these membrane fractions, are likely to be the binding sites that account for this vitamin D-dependent Ca2+ uptake.

scholarly journals Studies on the effect of vitamin D on calcium absorption and transport

1969 ◽  
Vol 112 (3) ◽  
pp. 275-283 ◽  
Author(s):  
George Hashim ◽  
Irwin Clark
Keyword(s):  
Vitamin D ◽  
Small Intestine ◽  
Calcium Absorption ◽  
Active Process ◽  
Hypervitaminosis D ◽  
Glycolytic Activity ◽  
Mucosal Cells ◽  
Intestinal Mucosal Cells ◽  
Uptake And Release

1. Mucosal cells of the small intestine obtained from rats deprived of vitamin D or given excessive amounts of the vitamin accumulated significantly more calcium than did cells from control animals. 2. Mucosal cells from vitamin D-deficient rats released less calcium than did cells from normal or hypervitaminotic D animals. 3. Studies in vivo showed that the transfer of 45Ca from the intestine to the blood was delayed in vitamin D deficiency, but was accelerated in hypervitaminosis D. 4. The findings support the thesis that vitamin D is involved in the release of calcium rather than in its uptake by mucosal cells. 5. Further evidence is presented suggesting that uptake of calcium by intestinal mucosal cells at 0° is primarily passive, whereas at 38° uptake and release are effected by an active process that depends on energy derived from glycolytic activity.

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