Calcium transport in rat small intestine in vitro and in vivo

1972 ◽  
Vol 273 (4) ◽  
pp. 352-365 ◽  
Author(s):  
Klaus Ewe
Keyword(s):  
Small Intestine ◽  
Calcium Transport ◽  
Rat Small Intestine

scholarly journals Absorption of lactulose from mammalian gastrointestinal tract

1979 ◽  
Vol 41 (1) ◽  
pp. 47-51 ◽  
Author(s):  
D. F. Evered ◽  
F. Sadoogh-Abasian
Keyword(s):  
Small Intestine ◽  
Calcium Ions ◽  
Clinical Evidence ◽  
Buccal Cavity ◽  
Rat Small Intestine ◽  
Sodium Ions ◽  
Mode Of Transport ◽  
Poor Absorption

1. The disaccharide lactulose (galactosyl-β-1,4-fructose) was poorly absorbed from rat small intestine in vitro and human mouth in vivo.2. These results confirm indirect clinical evidence of poor absorption from the intestine.3. The presence of calcium ions, or absence of sodium ions, had no effect on lactulose absorption from the buccal cavity.4. The presence of ouabain, or absence of Na+, did not decrease the absorption of lactulose from small intestine.5. It is thought that the mode of transport, in both instances, is by passive diffusion with the concentration gradient.

Uptake and compartmental distribution of fatty acid by rat small intestine in vivo

1975 ◽  
Vol 228 (5) ◽  
pp. 1409-1414
Author(s):  
S Mishkin ◽  
M Yalovsky ◽  
JI Kessler
Keyword(s):  
Fatty Acids ◽  
Small Intestine ◽  
Fatty Acid ◽  
Entire Length ◽  
Rat Small Intestine ◽  
Pass Through

The uptake and esterification of micellar [3-H]oleate and [14-C] palmitate were uniform along the entire length of the small intestine in vivo. Fatty acids (FA) radioactivity taken up by the small intestine could be described in terms of four functionally distinct compartments analogous to those described in vitro. The KRP-extractable compartment (KEC) and albumin-extractable compartment (AEC) contained reversibly adherent unesterified FA radioactivity, while the tissue free and esterified FA compartments contained irreversibly bound radioactivity. Wheras 27% and 63% of FA uptake were reversibly bound in the KEC and AEC by the most proximal and most distal regions of the small intestine in vitro (15), less than 10% was contained in these compartments in vivo, independent of location. Linear inverse relationships were found betweeen tissue FA esterification and proportion of FA radioactivity present in the KEC,AEC, and the tissue free FA compartment in vivo. These observations allow for the possibility that FA molecules pass through these compartments prior to esterification.

Oral intake of slowly digestible α-glucan, isomaltodextrin, stimulates glucagon-like peptide-1 secretion in the small intestine of rats

2019 ◽  
Vol 123 (6) ◽  
pp. 619-626
Author(s):  
Yoshihiko Komuro ◽  
Takashi Kondo ◽  
Shingo Hino ◽  
Tatsuya Morita ◽  
Naomichi Nishimura
Keyword(s):  
Small Intestine ◽  
Oral Delivery ◽  
Oral Intake ◽  
Membrane Vesicles ◽  
Rat Small Intestine ◽  
Maize Starch ◽  
Glucagon Like Peptide ◽  
Glucagon Like Peptide 1

AbstractTo investigate whether oral intake of highly branched α-glucan isomaltodextrin (IMD) could stimulate ileal glucagon-like peptide-1 (GLP-1) secretion, we examined (1) the digestibility of IMD, (2) the digestion and absorption rates of IMD, in rat small intestine and (3) portal GLP-1 concentration in rats given IMD. In Expt 1, ileorectostomised rats were given a 3 % IMD diet for 10 d. Separately, a 16-h in vitro digestion of IMD, using porcine pancreatic α-amylase and brush-border membrane vesicles from rat small intestine, was conducted. In Expt 2, upon 24-h fasting, rats were given any of glucose, IMD and high-amylose maize starch (HAMS) (1 g/kg of body weight). In Expt 3, caecectomised rats were given 0·2 % neomycin sulphate and a 5 % IMD diet for 10 d. The in vivo and in vitro digestibility of IMD was 70–80 %. The fraction of IMD digested in vitro for the first 120 min was 67 % of that in maize starch. The AUC for 0–120 min of plasma glucose concentration was significantly lower in HAMS group and tended to be lower in IMD group than in the glucose group. Finally, we also observed that, when compared with control rats, glucose of IMD significantly stimulated and improved the concentration of portal active GLP-1 in antibiotic-administered, caecectomised rats. We concluded that IMD was slowly digested and the resulting glucose stimulated GLP-1 secretion in rat small intestine. Oral delivery of slowly released IMD glucose to the small intestine probably exerts important, yet unknown, physiological effects on the recipient.

Intestinal calcium transport in the spontaneously hypertensive rat: response to calcium depletion

1986 ◽  
Vol 250 (4) ◽  
pp. G412-G419
Author(s):  
H. P. Schedl ◽  
D. L. Miller ◽  
R. L. Horst ◽  
H. D. Wilson ◽  
K. Natarajan ◽  
...  
Keyword(s):  
Vitamin D ◽  
Small Intestine ◽  
Calcium Transport ◽  
Spontaneously Hypertensive Rat ◽  
Calcium Depletion ◽  
Spontaneously Hypertensive ◽  
Distal Small Intestine ◽  
Wistar Kyoto

We previously found intestinal Ca2+ transport to be lower in the spontaneously hypertensive (SH) as compared with the Wistar-Kyoto control (WKY) rat. These animals were fed a relatively high (1%) Ca2+ diet, and the concentration of 1 alpha,25-dihydroxycholecalciferol [1 alpha,25(OH)2D3] in serum was the same in both groups. In the present experiment we tested the possibility that the lower Ca2+ transport in the SH rat was the result of unresponsiveness to 1 alpha,25(OH)2D3. We fed diets high and low in Ca2+ and measured serum 1 alpha,25(OH)2D3 and Ca2+ transport. Serum 1 alpha,25(OH)2D3 increased in response to Ca2+ depletion at both 5 and 12 wk in both the WKY and SH rat. With high-Ca2+ diet, Ca2+ transport was lower in SH than in WKY when studied 1) in vitro in duodenum at 5 wk of age, and 2) in vivo in proximal and distal small intestine at 12 wk of age. Ca2+ transport increased in SH in response to Ca2+ depletion, but not in WKY, except in distal small intestine in vivo at 12 wk. In summary, although Ca2+ transport is lower in the SH as compared with the WKY rat when vitamin D activity is basal through feeding a high-Ca2+ diet, Ca2+ transport increases in the SH rat in response to the increase in 1 alpha,25(OH)2D3 produced by feeding a low-Ca2+ diet. We conclude that 1) the vitamin D-regulated component of mediated Ca2+ transport is intact in the SH rat and is unrelated to hypertension, and 2) mediated Ca2+ transport under basal conditions, i.e., nonvitamin D-regulated, differs in the SH and WKY rats and may be related to hypertension.

scholarly journals Absence of gluconeogenesis in the rat small intestine: In vitro carbon 13 NMR and in vivo evidence

2007 ◽  
Vol 21 (5) ◽  
Author(s):  
Gabriel Baverel ◽  
Bernard Ferrier ◽  
Mireille Martin ◽  
Agnès Conjard ◽  
Fadi Saadé ◽  
...  
Keyword(s):  
Small Intestine ◽  
Rat Small Intestine

Uptake and esterification of plant sterols by rat small intestine

1981 ◽  
Vol 240 (1) ◽  
pp. G50-G55 ◽  
Author(s):  
A. K. Bhattacharyya
Keyword(s):  
Small Intestine ◽  
Tissue Concentration ◽  
Intestinal Content ◽  
Plant Sterols ◽  
Cell Uptake ◽  
Side Chain ◽  
Mucosal Cell ◽  
Rat Small Intestine

The commonly found plant sterols, beta-sitosterol, campesterol, and stigmasterol, differ structurally from cholesterol only in side chains but are absorbed in much smaller amounts than cholesterol. Because intestinal mucosal cell uptake and esterification are important steps in absorption, these were studied in vivo after feeding the sterols and in vitro using everted sacs of rat small intestine. The studies showed that campesterol uptake was significantly higher than that of beta-sitosterol, whereas stigmasterol uptake was extremely low throughout the intestine. The total intestinal content of campesterol was 2.223 mg/g or about 14% of the dose fed as compared with 1.496 mg/g or 7.4% for beta-sitosterol and only 0.392 mg/g or 2.3% for stigmasterol. Intestinal tissue concentration of esterified campesterol was higher than that of beta-sitosterol, whereas that of esterified stigmasterol was extremely low. The results suggest that campesterol absorption would be higher than that of beta-sitosterol; stigmasterol probably would not be absorbed in any significant amount because of its negligible uptake due to its inability to partition out of the mixed micelles. It appears that the structure of the side chain of a sterol is an important determinant for uptake and esterification, and probably absorption, in the small intestine.

Release of Dipeptide Hydrolase Activities from Rat Small Intestine Perfused in Vitro and in Vivo

1979 ◽  
Vol 57 (6) ◽  
pp. 529-534 ◽  
Author(s):  
M. L. G. Gardner ◽  
Jane A. Plumb
Keyword(s):  
Small Intestine ◽  
Physiological Significance ◽  
Peptide Transport ◽  
Rat Small Intestine ◽  
Experimental Procedure ◽  
Specific Process ◽  
Whole Cells ◽  
Anaesthetized Rats

1. Hydrolase activities against three dipeptides were measured in mucosal cytoplasm in unperfused intestines and in mucosal cytoplasm, luminal effluents and serosal secretions after perfusion in vitro and in vivo for 1 h. Intestines in vitro were prepared both from anaesthetized rats and from freshly killed rats. 2. Only 0·6–1·9% of the initial cytoplasmic activity was recovered in the luminal effluent when intestines in vitro were prepared from anaesthetized rats. Recoveries in luminal effluents were similar (1·3–3·3%) during perfusion in vivo. 3. Losses of dipeptidases into the luminal effluent were four to eight times greater when intestines in vitro were prepared from freshly killed animals. 4. Similar losses of dipeptidases into the secretion on to the serosal surface were observed; they too were much greater when intestines were prepared from freshly killed animals. 5. Small losses of mucosal DNA during perfusion were also observed; however, losses of cytoplasmic peptidases were consistently slightly greater. 6. Enzyme loss therefore probably occurs both by sloughing of whole cells and by a more specific process which is greatly influenced by experimental procedure. Caution is necessary in the interpretation of peptide transport experiments in vitro, although the possibility that intraluminal hydrolysis is of physiological significance must not be excluded.

Differences in uptake and esterification of saturated analogues of cholesterol by rat small intestine

1986 ◽  
Vol 251 (4) ◽  
pp. G495-G500 ◽  
Author(s):  
A. K. Bhattacharyya
Keyword(s):  
Small Intestine ◽  
Intestinal Mucosa ◽  
Cholesterol Content ◽  
Cell Uptake ◽  
Cholesterol Concentration ◽  
Mucosal Cell ◽  
Rat Small Intestine ◽  
Intestinal Tissue

Coprostanol and cholestanol are two saturated analogues of cholesterol. The former, which is the A/B ring isomer of cholesterol, is a nonabsorbable sterol, whereas the latter, which has an A/B ring configuration closer to that of cholesterol, is absorbed only half as efficiently as cholesterol. Intestinal mucosal cell uptake and esterification, two important steps in absorption, were studied in vivo after feeding the sterols and in vitro using everted sacs of rat small intestine. The results showed that the intestinal tissue content of coprostanol, total and esterified, were significantly lower than that of cholestanol. Total cholesterol concentration in the intestinal tissue was similar throughout but the esterified cholesterol content increased significantly throughout the length of the intestine compared with controls. The study suggests that cholestanol is absorbable because its uptake and esterification are not limited, whereas coprostanol is nonabsorbable because its uptake and esterification are limited in the intestinal mucosa. Also, the two sterols stimulate the activities of cholesterol esterase, one of the cholesterol esterifying enzymes, in the intestinal mucosa. The present study along with previous studies suggests that the structure of the sterol molecule as a whole appears to be the important determinant for its uptake and esterification, and probably absorption, in the small intestine.

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