Luminal peptide YY-releasing factors in the isolated vascularly perfused rat colon

1996 ◽  
Vol 151 (3) ◽  
pp. 421-429 ◽  
Author(s):  
P Plaisancié ◽  
V Dumoulin ◽  
J-A Chayvialle ◽  
J-C Cuber
Keyword(s):  
Amino Acids ◽  
Oleic Acid ◽  
Peptide Yy ◽  
Total Concentration ◽  
Gum Arabic ◽  
Rat Colon ◽  
Maximal Response ◽  
L Cells ◽  
Releasing Factors ◽  
Dose Dependent

Abstract Peptide YY (PYY) is produced in endocrine L cells primarily localized in the distal bowel. These open-type L cells make contact with the intestinal chyme which may thus affect their secretory activity. The aim of the present study was to examine a large variety of luminal compounds found in colonic contents for their potential as PYY-releasing factors, using the isolated vascularly perfused rat colon. The release of PYY into the portal effluent was measured by a specific RIA. Luminal administration of 5 mm glucose or 0·5% (w/v) starch for 30 min did not induce significant release of PYY. Oleic acid (10 and 100 mm) also did not significantly increase PYY secretion. A pharmacological concentration of glucose (250 mm) and a mixture of amino acids (total concentration 250 mm) both induced PYY secretion (200% of basal). Pectin, a polygalacturonic acid, evoked dose-dependent secretion of PYY-like immunoreactivity over the range 0·1–0·5% (w/v). The maximal response was observed after infusion of 0·5% pectin which induced a prompt and sustained release of PYY (300% of basal). Galacturonic acid itself (5%) produced marked PYY secretion. Gum arabic (0·5%) induced a gradual increase in portal PYY concentration (maximal response 250% of the basal value) whereas cellulose (0·5%) did not elicit PYY secretion. Luminal n-butyrate over the range 0·5–5 mm produced a dose-dependent release of PYY (maximal response 300% of the basal value with 5 mm n-butyrate). Increasing the concentration of n-butyrate to 100 mm provoked a gradual decrease in PYY secretion. Propionate was a less potent stimulant than n-butyrate, and acetate did not increase PYY secretion above the basal value. At a concentration of 2 or 20 mm, taurocholate, cholate and deoxycholate brought about PYY secretion while hyodeoxycholate was without effect. In conclusion, glucose and amino acids may mediate PYY release but only when they are present at high supraphysiological concentrations in the colon while oleic acid does not produce any PYY secretion. Physiological concentrations of fibers (pectin, gum arabic), short-chain fatty acids (n-butyrate, propionate) and bile salts (taurocholate, cholate, deoxycholate) are all potent stimulants of PYY release. Whether the release of PYY by luminal factors is coupled to water and electrolyte transfer via a local/paracrine pathway remains an open question which requires additional work with the isolated vascularly perfused colon preparation. Journal of Endocrinology (1996) 151, 421–429

Luminal glucagon-like peptide-1(7–36) amide-releasing factors in the isolated vascularly perfused rat colon

1995 ◽  
Vol 145 (3) ◽  
pp. 521-526 ◽  
Author(s):  
P Plaisancié ◽  
V Dumoulin ◽  
J-A Chayvialle ◽  
J-C Cuber
Keyword(s):  
Bile Acids ◽  
Total Concentration ◽  
Gum Arabic ◽  
Secretory Activity ◽  
Short Chain Fatty Acids ◽  
Rat Colon ◽  
Maximal Response ◽  
L Cells ◽  
Glucagon Like Peptide ◽  
Glucagon Like Peptide 1

Abstract Glucagon-like peptide-1 (GLP-1) is released from endocrine cells of the distal part of the gut after ingestion of a meal. GLP-1 secretion is, in part, under the control of hormonal and/or neural mechanisms. However, stimulation of the colonic L cells may also occur directly by the luminal contents. This was examined in the present study, using an isolated vascularly perfused rat colon. GLP-1 immunoreactivity was measured in the portal effluent after luminal infusion of a variety of compounds which are found in colonic contents (nutrients, fibers, bile acids, short-chain fatty acids (SCFAs)). Oleic acid (100 mm) or a mixture of amino acids (total concentration 250 mm), or starch (0·5%, w/v) did not increase GLP-1 secretion over basal value. A pharmacological concentration of glucose (250 mm) elicited a marked release of GLP-1 which was maximal at the end of infusion (400% of basal), while 5 mm glucose was without effect on secretion. Pectin evoked a dose-dependent release of GLP-1 over the range 0·1–0·5% (w/v) with a maximal response at 360% of basal when 0·5% pectin was infused. Cellulose or gum arabic (0·5%) did not modify GLP-1 secretion. The SCFAs acetate, propionate or butyrate (5, 20 and 100 mm) did not induce a significant release of GLP-1. Among the four bile acids tested, namely taurocholate, cholate, deoxycholate and hyodeoxycholate, the last one was the most potent at eliciting a GLP-1 response with a maximal release at 300% and 400% of the basal value when 2 and 20 mm bile acid were administered respectively. In conclusion, some fibres and bile acids are capable of releasing colonic GLP-1 in rats and may contribute to the secretory activity of colonic L cells. Journal of Endocrinology (1995) 145, 521–526

scholarly journals Bile acids drive colonic secretion of glucagon-like-peptide 1 and peptide-YY in rodents

2019 ◽  
Vol 316 (5) ◽  
pp. G574-G584 ◽  
Author(s):  
Charlotte Bayer Christiansen ◽  
Samuel Addison Jack Trammell ◽  
Nicolai Jacob Wewer Albrechtsen ◽  
Kristina Schoonjans ◽  
Reidar Albrechtsen ◽  
...  
Keyword(s):  
Bile Acids ◽  
G Protein ◽  
Peptide Yy ◽  
Whole Body ◽  
Rat Colon ◽  
G Protein Coupled Receptor ◽  
L Cells ◽  
Glucagon Like Peptide ◽  
Glucagon Like Peptide 1 ◽  
G Protein Coupled

A large number of glucagon-like-peptide-1 (GLP-1)- and peptide-YY (PYY)-producing L cells are located in the colon, but little is known about their contribution to whole body metabolism. Since bile acids (BAs) increase GLP-1 and PYY release, and since BAs spill over from the ileum to the colon, we decided to investigate the ability of BAs to stimulate colonic GLP-1 and PYY secretion. Using isolated perfused rat/mouse colon as well as stimulation of the rat colon in vivo, we demonstrate that BAs significantly enhance secretion of GLP-1 and PYY from the colon with average increases of 3.5- and 2.9-fold, respectively. Furthermore, we find that responses depend on BA absorption followed by basolateral activation of the BA-receptor Takeda-G protein-coupled-receptor 5. Surprisingly, the apical sodium-dependent BA transporter, which serves to absorb conjugated BAs, was not required for colonic conjugated BA absorption or conjugated BA-induced peptide secretion. In conclusion, we demonstrate that BAs represent a major physiological stimulus for colonic L-cell secretion.NEW & NOTEWORTHY By the use of isolated perfused rodent colon preparations we show that bile acids are potent and direct promoters of colonic glucagon-like-peptide 1 and peptide-YY secretion. The study provides convincing evidence that basolateral Takeda-G protein-coupled-receptor 5 activation is mediating the effects of bile acids in the colon and thus add to the existing literature described for L cells in the ileum.

scholarly journals Effects of neurotransmitters, gut hormones, and inflammatory mediators on mucus discharge in rat colon

1998 ◽  
Vol 275 (5) ◽  
pp. G1073-G1084 ◽  
Author(s):  
Pascale Plaisancié ◽  
Aline Barcelo ◽  
Frederic Moro ◽  
Jean Claustre ◽  
Jean-Alain Chayvialle ◽  
...  
Keyword(s):  
Peptide Yy ◽  
Gut Hormones ◽  
Rat Colon ◽  
Maximal Response ◽  
Enzyme Linked Immunosorbent Assay ◽  
Control Loops ◽  
Colonic Mucin ◽  
Calcitonin Gene ◽  
Glucagon Like Peptide 1 ◽  
Mucin Release

The effect of potential mediators of mucus secretion was investigated in the isolated vascularly perfused rat colon by using a sandwich enzyme-linked immunosorbent assay for rat colonic mucin and by histochemical analysis. Bethanechol (100–200 μM), bombesin (100 nM), and vasoactive intestinal peptide (VIP, 100 nM) provoked a dramatic mucin discharge (maximal response at 900, 900, and 600% of control loops, respectively). VIP-stimulated mucin secretion was abolished by tetrodotoxin, whereas atropine was without effect. In contrast, both tetrodotoxin and atropine significantly decreased mucin release induced by bombesin. Isoproterenol or calcitonin gene-related peptide was without effect. Serotonin (1–5 μM) and peptide YY (10 nM) evoked mucin discharge, whereas glucagon-like peptide-1 did not release mucin. Finally, bromolasalocid (20 μM), interleukin-1β (0.25 nM), sodium nitroprusside (1 mM), and dimethyl-PGE2(2.5 μM) induced mucus discharge. The results demonstrated a good correlation between the immunological method and histological analysis. In conclusion, these findings suggest a role for the enteric nervous system, the enteroendocrine cells, and resident immune cells in mediation of colonic mucus release.

Roux-en-Y Gastrointestinal Bypass Promotes Activation of TGR5 and Peptide YY

2020 ◽  
Vol 20 (8) ◽  
pp. 1262-1267
Author(s):  
Haojun Yang ◽  
Hanyang Liu ◽  
YuWen Jiao ◽  
Jun Qian
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Metabolic Diseases ◽  
Peptide Yy ◽  
The Body ◽  
Wild Type ◽  
L Cells ◽  
Body Weights ◽  
Gastrointestinal Bypass ◽  
G Protein Coupled

Background: G protein-coupled bile acid receptor (TGR5) is involved in a number of metabolic diseases. The aim of this study was to identify the role of TGR5 after Roux-en-Y gastric bypass (GBP). Methods: Wild type and TGR5 knockout mice (tgr5-/-) were fed a high-fat diet (HFD) to establish the obesity model. GBP was performed. The changes in body weight and food intake were measured. The levels of TGR5 and peptide YY (PYY) were evaluated by RT-PCR, Western blot, and ELISA. Moreover, the L-cells were separated from wild type and tgr5-/- mice. The levels of PYY in L-cells were evaluated by ELISA. Results: The body weights were significantly decreased after GBP in wild type mice (p<0.05), but not tgr5-/- mice (p>0.05). Food intake was reduced after GBP in wild type mice, but also not significantly affected in tgr5-/- mice (p>0.05). The levels of PYY were significantly increased after GBP compared with the sham group (p<0.05); however, in tgr5-/- mice the expression of PYY was not significantly affected (p>0.05). After INT-777 stimulation in L-cells obtained from murine intestines, the levels of PYY were significantly increased in L-cells tgr5+/+ (p<0.05). Conclusion: Our study suggests that GBP up-regulated the expression of TGR5 in murine intestines, and increased the levels of PYY, which further reduced food intake and decreased the body weight.

scholarly journals Basil as Secondary Crop in Cascade Hydroponics: Exploring Salinity Tolerance Limits in Terms of Growth, Amino Acid Profile, and Nutrient Composition

Horticulturae ◽  
2021 ◽  
Vol 7 (8) ◽  
pp. 203
Author(s):  
Denisa Avdouli ◽  
Johannes F. J. Max ◽  
Nikolaos Katsoulas ◽  
Efi Levizou
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Salinity Tolerance ◽  
Total Concentration ◽  
Amino Acid Profile ◽  
Total Amino Acid ◽  
Cascade System ◽  
Hydroponic System ◽  
Salinity Levels ◽  
Use Efficiency

In a cascade hydroponic system, the used nutrient solution drained from a primary crop is directed to a secondary crop, enhancing resource-use efficiency while minimizing waste. Nevertheless, the inevitably increased EC of the drainage solution requires salinity-tolerant crops. The present study explored the salinity-tolerance thresholds of basil to evaluate its potential use as a secondary crop in a cascade system. Two distinct but complemented approaches were used; the first experiment examined basil response to increased levels of salinity (5, 10 and 15 dS m−1, compared with 2 dS m−1 of control) to identify the limits, and the second experiment employed a cascade system with cucumber as a primary crop to monitor basil responses to the drainage solution of 3.2 dS m−1. Growth, ascorbate content, nutrient concentration, and total amino acid concentration and profile were determined in both experiments. Various aspects of basil growth and biochemical performance collectively indicated the 5 dS m−1 salinity level as the upper limit/threshold of tolerance to stress. Higher salinity levels considerably suppressed fresh weight production, though the total concentration of amino acids showed a sevenfold increase under 15 dS m−1 and 4.5-fold under 5 and 10 dS m−1 compared to the control. The performance of basil in the cascade system was subject to a compromise between a reduction of fresh produce and an increase of total amino acids and ascorbate content. This outcome indicated that basil performed well under the conditions and the system employed in the present study, and might be a good candidate for use as a secondary crop in cascade-hydroponics systems.

scholarly journals Fate of fructo-oligosaccharides in the human intestine

1996 ◽  
Vol 76 (2) ◽  
pp. 211-221 ◽  
Author(s):  
Martine S. Alles ◽  
Joseph G. A. J. Hautvast ◽  
Fokko M. Nagengast ◽  
Ralf Hartemink ◽  
Katrien M. J. Van Laere ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Total Concentration ◽  
Latin Square ◽  
Short Chain Fatty Acids ◽  
Short Chain ◽  
Colonic Fermentation ◽  
Faecal Samples ◽  
Faecal Weight ◽  
Dose Dependent ◽  
Chain Fatty Acids

There is a need for studies on colonic fermentation in order to learn more abouthealth and diseases of the colon. The aim of the present study was to evaluate the fate of twodifferent doses of fructo-oligosaccharides (5 and 15 g/d) v. glucose in the intestine of healthy men. Twenty-four volunteers participated in a 5-weekstudy. The study was a completely balanced multiple crossover trial using an orthogonal Latin-square design for three periods, with supplement periods of 7 d and two 7 d wash-out periods. Breath samples and faecal samples were collected. There was a clear gaseous response to the consumption of fructo-oligosaccharides. The highest dose significantly increased 24 h integratedexcretion of breath H2 (P < 0·05). Breath H2 excretion after ingestion of 5 g fructo-oligosaccharides was higher than control, but did not reach significance. No effects on the total concentration of short-chain fatty acids in faeces were observed, no modification of the molar proportions of the various short-chain fatty acids was observed. The faecal pH did not change. No changes in faecal weight were observed. No fructo-oligosaccharides were recovered in faeces. We conclude that fructo-oligosaccharides added to the diet of young Western subjects are fully metabolized in the large intestine. The level of fermentation seems to be dose-dependent.

Role of insulin and branched-chain amino acids in regulating protein metabolism during fasting

1990 ◽  
Vol 258 (6) ◽  
pp. E907-E917 ◽  
Author(s):  
M. Frexes-Steed ◽  
M. L. Warner ◽  
N. Bulus ◽  
P. Flakoll ◽  
N. N. Abumrad
Keyword(s):  
Amino Acids ◽  
Protein Metabolism ◽  
Insulin Dose ◽  
Group Iii ◽  
Group I ◽  
Tissue Sensitivity ◽  
Branched Chain ◽  
Independent Effects ◽  
Dose Dependent

This study examines the independent effects of insulin and amino acids on protein metabolism after a 12-h and 4-day fast in healthy volunteers. Leucine (Leu) kinetics were examined during sequential insulin infusions of 0 (group I) or 0.0125 (groups II and III), 1.2, and 10 mU.kg-1.min-1. Plasma Leu was maintained at 12-h fasted levels in groups I and II and at 84-h fasted levels in group III. Four-day fast (vs. 1 day, P less than 0.01) was associated with a 79% drop in plasma insulin and elevations in plasma Leu (122%), Leu rates of appearance (Ra) (21%), and Leu oxidation (56%), and no change in nonoxidative rates of disappearance (Rd). Insulin resulted in a dose-dependent suppression of endogenous Leu Ra with group III = I greater than II. Leu oxidation rose 1.7-fold in group III at the highest insulin dose but remained stable in the two other groups. In conclusion, 4-day fasting is associated with enhanced proteolysis and Leu oxidation with no change in nonoxidative Rd (protein synthesis). Elevated branched-chain (and other) amino acids were required to restore tissue sensitivity and specificity to the effects of insulin on protein metabolism after 4 days of fasting.

Mechanism of oleic acid-induced inhibition on gastric acid secretion in rats

1991 ◽  
Vol 260 (4) ◽  
pp. G564-G570 ◽  
Author(s):  
J. C. Rhee ◽  
T. M. Chang ◽  
K. Y. Lee ◽  
Y. H. Jo ◽  
W. Y. Chey
Keyword(s):  
Oleic Acid ◽  
Acid Secretion ◽  
Peptide Yy ◽  
Acid Output ◽  
Inhibitory Effect ◽  
Rabbit Serum ◽  
Similar Degree ◽  
Normal Rabbit Serum ◽  
Anesthetized Rats ◽  
Acid Acid

We investigated the existence of an enterogastrone in rats induced by duodenal administration of oleic acid. Acid secretion by the luminally perfused stomach was stimulated in anesthetized rats by intravenous infusion of 0.3 micrograms.kg-1.h-1 pentagastrin. Intraduodenal administration of 3 mmol of oleic acid produced a profound inhibition (94%) of pentagastrin-stimulated acid output in 10 rats (P less than 0.01). Of several peptides in plasma including secretin, neurotensin, somatostatin, and peptide YY, only secretin was found to increase significantly (P less than 0.001). A similar degree of inhibition of acid output (93%) was caused by porcine secretin, 5.6 pmol.kg-1.h-1, given intravenously to mimic the plasma level of secretin produced by oleic acid infusion. The inhibitory effect of oleic acid on the acid secretion was completely reversed by intravenous injection of a rabbit antisecretin serum but not by a normal rabbit serum. These observations strongly suggest that the inhibition was mediated via circulating secretin. The inhibition produced by either oleic acid or secretin was completely blocked by indomethacin. The blocking action was completely reversed by intravenous administration of 48 micrograms.kg-1.h-1 prostaglandin E2. We conclude that endogenous secretin is a major enterogastrone released by oleic acid in anesthetized rats and that the inhibitory action of secretin requires endogenous prostaglandins.

Plasma concentrations of glucocorticoids in white-tailed deer: the effect of acute ACTH and dexamethasone administration

1990 ◽  
Vol 68 (10) ◽  
pp. 2123-2129 ◽  
Author(s):  
J. H. Smith ◽  
G. A. Bubenik
Keyword(s):  
Adrenal Gland ◽  
Intramuscular Injection ◽  
Plasma Concentrations ◽  
Maximal Response ◽  
Rapid Decline ◽  
Immature Female ◽  
Castrate Male ◽  
Adrenal Response ◽  
Serial Samples ◽  
Dose Dependent

To study the response of the adrenal gland of white-tailed deer to exogenous ACTH, eight penned animals (five mature intact males, one mature castrate male, one adult castrate female, and one immature female) were sedated with xylazine and ketamine and then challenged with various doses of ACTH with and without dexamethasone (DX) pretreatment. Plasma concentrations of cortisol and cortiscosterone were determined by radioimmunoassay in serial samples taken from a jugular cannula. Rapid, dose-dependent increases lasting over 5 h were observed after intramuscular injection of 10, 20, or 40 IU of porcine ACTH. The ratio of cortisol to corticosterone varied from 2:1 to 40:1. Maximum cortisol concentrations averaged 14.9, 20.3, and 21.3 μg/dL, respectively. Intravenous infusion of 5 mg of DX induced a rapid decline of cortisol levels. Administration of 20 or 40 IU of ACTH 140 min after DX caused increases of cortisol which were not different from those when ACTH was given alone. It was concluded that (i) xylazine and ketamine immobilization is suitable for study of the adrenal activity in deer, (ii) 20 IU of ACTH elicits maximal response of cortisol and corticosterone, (iii) DX pretreatment can result in minimal cortisol concentrations but its use is not essential for studies of adrenal response to ACTH, and (iv) the adrenal response to ACTH of females and castrate males is similar to that of intact males.

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