Quantitative assessment of villous motility

1987 ◽  
Vol 252 (2) ◽  
pp. G250-G256 ◽  
Author(s):  
W. A. Womack ◽  
J. A. Barrowman ◽  
W. H. Graham ◽  
J. N. Benoit ◽  
P. R. Kvietys ◽  
...  
Keyword(s):  
Small Intestine ◽  
Fatty Acid ◽  
Amino Acid ◽  
Surface Temperature ◽  
Quantitative Assessment ◽  
Current Knowledge ◽  
Intermediate Frequency ◽  
Quantitative Information ◽  
Physiological Importance ◽  
Observation Period

A videomicroscopic method was used to quantitatively analyze villous motility in the dog small intestine. The frequency and duration of villous contractions (retractions) were measured in the duodenum, midjejunum, and distal ileum under controlled conditions. A pronounced gradient of villous motility was evident along the bowel. The duodenum exhibited the highest frequency (7.3 +/- 0.1/min) and longest duration (2.6 +/- 0.1 s) of contraction; the jejunum exhibited an intermediate frequency and duration of contraction (4.0 +/- 0.1/min, 2.1 +/- 0.1 s), and the lowest values were measured in the ileum (2.0 +/- 0.1/min and 1.8 +/- 0.1 s). In contrast to the retraction movements, the frequency of pendular villous movements (whipping, swaying movements without shortening) was highest in the jejunum and lowest in the duodenum. The frequency and duration of villous contractions (retractions) remained relatively constant over a 2-h observation period. Reducing mucosal surface temperature from 38 to 30 degrees C caused the frequency of contraction to fall by 33% and the duration to increase by 106%. Varying the suffusate pH within the physiological range of 5.0-7.4 produced no significant effects on jejunal villous motility. Suffusion with glucose (140 and 280 mM) failed to alter villous motility. However, amino acid (15 and 30 mM) and fatty acid (10 mM) solutions significantly increased contraction frequency by 30-50% and 90%, respectively. The videomicroscopic method provides useful quantitative information, which should extend current knowledge regarding the regulation and physiological importance of villous motility.

scholarly journals Quantitative aspects of fatty acid biohydrogenation, absorption and transfer into milk fat in the lactating goat, with special reference to the cis- and trans-isomers of octadecenoate and linoleate

1972 ◽  
Vol 130 (2) ◽  
pp. 607-617 ◽  
Author(s):  
R. Bickerstaffe ◽  
D. E. Noakes ◽  
E. F. Annison
Keyword(s):  
Small Intestine ◽  
Fatty Acid ◽  
Milk Fat ◽  
Complex Mixture ◽  
Quantitative Information ◽  
Trans Isomers ◽  
Cis And Trans Isomers ◽  
Lactating Goats ◽  
Cis And Trans ◽  
Ruminal Biohydrogenation

1. Surgically prepared lactating goats were used to obtain quantitative information on the biohydrogenation and absorption of dietary fat, and on the mammary uptake and transfer into milk fat of the complex mixture of cis- and trans-isomers of octadecenoate that arise during ruminal biohydrogenation. 2. About 90% of dietary linolenate, linoleate and oleate was hydrogenated in the rumen, and the availability to the animals of the essential fatty acid, linoleate, represented only 0.5–1.5% of the total dietary energy. 3. The intra-ruminal administration of 14C-labelled linolenate and linoleate showed that these acids were not absorbed from the rumen, in agreement with previous work. 4. No selectivity was observed in the metabolism of the geometrical and positional isomers of octadecenoate: their rates of absorption from the small intestine, transfer into lymph, uptake by the mammary gland and appearance in milk fat were similar. 5. The desaturase activity of intestinal epithelium was demonstrated by the appearance in lymph of [1-14C]oleate after the addition of [1-14C]stearate to the small intestine.

Hepatic cytochrome P-450 reductase-null mice show reduced transcriptional response to quercetin and reveal physiological homeostasis between jejunum and liver

2006 ◽  
Vol 291 (1) ◽  
pp. G63-G72 ◽  
Author(s):  
David M. Mutch ◽  
Vanessa Crespy ◽  
Jennifer Clough ◽  
Colin J. Henderson ◽  
Sofiane Lariani ◽  
...  
Keyword(s):  
Small Intestine ◽  
Fatty Acid ◽  
Amino Acid ◽  
Fatty Acid Metabolism ◽  
Amino Acid Metabolism ◽  
Acid Metabolism ◽  
Glutathione Metabolism ◽  
Sterol Metabolism ◽  
Cytochrome P 450 ◽  
Hepatic Cytochrome

Using mice deficient in hepatic cytochrome P-450 oxidoreductase (POR), which disables the liver cytochrome P-450 system, we examined the metabolism and biological response of the anticarcinogenic flavonoid, quercetin. Profiling circulating metabolites revealed similar profiles over 72 h in wild-type (WT) and POR-null (KO) mice, showing that hepatic P450 and reduced biliary secretion do not affect quercetin metabolism. Transcriptional profiling at 24 h revealed that two- to threefold more genes responded significantly to quercetin in WT compared with KO in the jejunum, ileum, colon, and liver, suggesting that hepatic P450s mediate many of the biological effects of quercetin, such as immune function, estrogen receptor signaling, and lipid, glutathione, purine, and amino acid metabolism, even though quercetin metabolism is not modified. The functional interpretation of expression data in response to quercetin (single dose of 7 mg/animal) revealed a molecular relationship between the liver and jejunum. In WT animals, amino acid and sterol metabolism was predominantly modulated in the liver, fatty acid metabolism response was shared between the liver and jejunum, and glutathione metabolism was modulated in the small intestine. In contrast, KO animals do not regulate amino acid metabolism in the liver or small intestine, they share the control of fatty acid metabolism between the liver and jejunum, and regulation of sterol metabolism is shifted from the liver to the jejunum and that of glutathione metabolism from the jejunum to the liver. This demonstrates that the quercetin-mediated regulation of these biological functions in extrahepatic tissues is dependent on the functionality of the liver POR. In conclusion, using a systems biology approach to explore the contribution of hepatic phase 1 detoxification on quercetin metabolism demonstrated the resiliency and adaptive capacity of a biological organism in dealing with a bioactive nutrient when faced with a tissue-specific molecular dysfunction.

scholarly journals Cytosolic phosphoenolpyruvate carboxykinase as a cataplerotic pathway in the small intestine

2018 ◽  
Vol 315 (2) ◽  
pp. G249-G258 ◽  
Author(s):  
Austin Potts ◽  
Aki Uchida ◽  
Stanislaw Deja ◽  
Eric D. Berglund ◽  
Blanka Kucejova ◽  
...  
Keyword(s):  
Amino Acids ◽  
Small Intestine ◽  
Fatty Acid ◽  
Amino Acid ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Postprandial Triglyceride ◽  
Amino Acid Profiles ◽  
Gluconeogenic Enzyme ◽  
Acid Esterification ◽  
Fatty Acid Esterification

Cytosolic phosphoenolpyruvate carboxykinase (PEPCK) is a gluconeogenic enzyme that is highly expressed in the liver and kidney but is also expressed at lower levels in a variety of other tissues where it may play adjunct roles in fatty acid esterification, amino acid metabolism, and/or TCA cycle function. PEPCK is expressed in the enterocytes of the small intestine, but it is unclear whether it supports a gluconeogenic rate sufficient to affect glucose homeostasis. To examine potential roles of intestinal PEPCK, we generated an intestinal PEPCK knockout mouse. Deletion of intestinal PEPCK ablated ex vivo gluconeogenesis but did not significantly affect glycemia in chow, high-fat diet, or streptozotocin-treated mice. In contrast, postprandial triglyceride secretion from the intestine was attenuated in vivo, consistent with a role in fatty acid esterification. Intestinal amino acid profiles and 13C tracer appearance into these pools were significantly altered, indicating abnormal amino acid trafficking through the enterocyte. The data suggest that the predominant role of PEPCK in the small intestine of mice is not gluconeogenesis but rather to support nutrient processing, particularly with regard to lipids and amino acids. NEW & NOTEWORTHY The small intestine expresses gluconeogenic enzymes for unknown reasons. In addition to glucose synthesis, the nascent steps of this pathway can be used to support amino acid and lipid metabolisms. When phosphoenolpyruvate carboxykinase, an essential gluconeogenic enzyme, is knocked out of the small intestine of mice, glycemia is unaffected, but mice inefficiently absorb dietary lipid, have abnormal amino acid profiles, and inefficiently catabolize glutamine. Therefore, the initial steps of intestinal gluconeogenesis are used for processing dietary triglycerides and metabolizing amino acids but are not essential for maintaining blood glucose levels.

Electron probe x-ray microanalysis and electron microscopy of amino acid absorption and transport by the small intestine: inhibition by chemical poisons and correlation to the elemental composition of the epithelial cells

1986 ◽  
Vol 44 ◽  
pp. 134-135
Author(s):  
A. J. Tousimis
Keyword(s):  
Small Intestine ◽  
Amino Acid ◽  
Epithelial Cells ◽  
Elemental Composition ◽  
Isotope Labeling ◽  
Structural Components ◽  
X Ray ◽  
Human Small Intestine ◽  
Transport Studies

The elemental composition of amino acids is similar to that of the major structural components of the epithelial cells of the small intestine and other tissues. Therefore, their subcellular localization and concentration measurements are not possible by x-ray microanalysis. Radioactive isotope labeling: I131-tyrosine, Se75-methionine and S35-methionine have been successfully employed in numerous absorption and transport studies. The latter two have been utilized both in vitro and vivo, with similar results in the hamster and human small intestine. Non-radioactive Selenomethionine, since its absorption/transport behavior is assumed to be the same as that of Se75- methionine and S75-methionine could serve as a compound tracer for this amino acid.

Free Fatty Acid Receptors as New Potential Targets in Colorectal Cancer

2020 ◽  
Vol 21 (14) ◽  
pp. 1397-1404
Author(s):  
Adrian Bartoszek ◽  
Jakub Fichna ◽  
Aleksandra Tarasiuk ◽  
Agata Binienda ◽  
Adam Fabisiak ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Fatty Acid ◽  
Free Fatty Acid ◽  
Current Knowledge ◽  
Developed Countries ◽  
Future Directions ◽  
Screening Programs ◽  
Pharmacological Targets ◽  
The Family ◽  
Free Fatty Acid Receptors

Colorectal cancer (CRC) is one of the most common cancers worldwide. In developed countries, its mortality remains high, yet the prevalence has established owing to effective screening programs; however due to the westernization of lifestyle, the incidences in many other countries have increased. Although the treatment of CRC has improved in the last few years, the side effects of these approaches cannot be neglected. Recently, members of the family of free fatty acid receptors (FFARs) have become attractive pharmacological targets in many diseases, including asthma; studies also point to their role in carcinogenesis. Here, we discuss current knowledge and future directions in FFAR research related to CRC. Contradictory results of FFARs modulation may derive from the pleiotropic effects of FFAR ligands, receptor distribution and different signal transduction. Hence, we indicate directions of further studies to fully use the potential of FFARs in CRC.

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