Demonstration and modification of intervillous pH profiles in rat small intestine in vitro

1989 ◽  
Vol 257 (4) ◽  
pp. G489-G495 ◽  
Author(s):  
H. Daniel ◽  
C. Fett ◽  
A. Kratz
Keyword(s):  
Small Intestine ◽  
Low Ph ◽  
Rat Small Intestine ◽  
Ph Profile ◽  
Subsequent Increase ◽  
Alkaline Secretion ◽  
Alkaline Fluid ◽  
Ph Profiles

The intervillous pH profiles along the crypt villus axis in different regions of the rat small intestine were measured in vitro by using pH-sensitive liquid ion-exchanger microelectrodes. A characteristic pH profile was observed in the duodenum and jejunum. A region of low pH was detected in the upper parts of the villi (pH 6.65 +/- 0.06 to 6.85 +/- 0.07), whereas pH at the villus base was always higher. In the ileum no gradient was observed (pH 7.26 +/- 0.05 to 7.31 +/- 0.05). Preincubation of the tissue in situ with 10 mM theophylline for 1 h caused an increase in the villus base pH in the jejunum (pH 7.24 +/- 0.04) and ileum (7.44 +/- 0.04) followed by a subsequent increase of the pH in the upper part of the villi. These results indicate that the low pH in the upper intervillous space may be related to H+ secretion occurring from the mature enterocytes, whereas the crypt cells may secrete a rather neutral or slightly alkaline fluid. Alkaline secretion from the crypts may be increased by theophylline, which changes the levels of cyclic nucleotides in the mucosa.

scholarly journals In vitro and in situ absorption of methionine sulfoxide in rat small intestine.

1982 ◽  
Vol 46 (10) ◽  
pp. 2533-2538 ◽  
Author(s):  
Masako HIGUCHI ◽  
Kimikazu IWAMI ◽  
Akio NAKAMURA ◽  
Kyoden YASUMOTO ◽  
Kazuo IWAI
Keyword(s):  
Small Intestine ◽  
Methionine Sulfoxide ◽  
Rat Small Intestine ◽  
In Situ Absorption

In situ demonstration of migration of dendritic cells released from rat small intestine to mesenteric lymph nodes

2001 ◽  
Vol 120 (5) ◽  
pp. A183-A183
Author(s):  
H KOBAYASHI ◽  
H NAGATA ◽  
S MIURA ◽  
T AZUMA ◽  
H SUZUKI ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Small Intestine ◽  
Lymph Nodes ◽  
Rat Small Intestine ◽  
Mesenteric Lymph Nodes ◽  
Mesenteric Lymph

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.

Pyruvate transport across mucosa of rat small intestine in vitro

1986 ◽  
Vol 14 (2) ◽  
pp. 299-300
Author(s):  
JOHN E. LAWRENCE ◽  
DEREK F. EVERED
Keyword(s):  
Small Intestine ◽  
Rat Small Intestine

Absorption of beta-casomorphins from autoperfused lamb and piglet small intestine

1990 ◽  
Vol 259 (3) ◽  
pp. G443-G452 ◽  
Author(s):  
L. C. Read ◽  
A. P. Lord ◽  
V. Brantl ◽  
G. Koch
Keyword(s):  
Small Intestine ◽  
Intestinal Lumen ◽  
Physiological Conditions ◽  
Naturally Occurring ◽  
Gut Epithelium ◽  
Measured Absorption ◽  
Beta Casein ◽  
Kinetics Of

beta-Casomorphins (beta-CMs) derived from milk beta-casein may exert various opiate activities in milk-fed infants. To assess the physiological significance of beta-CMs as a source of circulating opioids in infants, we measured absorption rates of several beta-CMs under near-physiological conditions using in situ autoperfused lamb intestine. The naturally occurring beta-CMs, beta-CM-7 and beta-CM-4-amide, were absorbed readily into blood with no transfer into lymph. Uptake peaked within several minutes of the luminal infusion of peptide but then declined sharply and stopped within a further 10-15 min. The recovery in blood, intestinal contents, and tissue at the end of the 30-min experiment was less than 1% of the infused dose. The low recovery was due to rapid proteolysis based on in vitro studies that demonstrated half-lives of less than 5 min in lamb blood, luminal contents, and lymph. The synthetic dipeptidyl peptidase IV-resistant analogue beta-[D-Ala2]CM- 4-amide was stable during incubation in blood, lymph, or luminal contents and was absorbed into blood at rates that were maximal within several minutes and remained steady for the 30-min period. We conclude that although natural beta-CMs are transferred across the lamb small intestine, rapid degradation within the intestinal lumen, gut epithelium, and blood would prevent entry into the circulation under normal conditions. Val-beta-CM-7, a putative stable precursor, had similar stability and kinetics of absorption to beta-CM-7, results that exclude Val-beta-CM-7 as a stable precursor for delivery of beta-CMs to the circulation. Essentially identical results to those in lambs were obtained in 7-day-old piglets.

Development of fatty acid esterification mechanisms in rat small intestine.

1979 ◽  
Vol 237 (5) ◽  
pp. E399 ◽  
Author(s):  
Y F Shiau ◽  
C Umstetter ◽  
K Kendall ◽  
O Koldovsky
Keyword(s):  
Small Intestine ◽  
Fatty Acid ◽  
Total Fatty Acid ◽  
Fetal Programming ◽  
Rat Small Intestine ◽  
Adult Rats ◽  
Major Pathway ◽  
Acid Esterification ◽  
Fatty Acid Esterification

Fatty acid esterification was measured in fetal jejunal and ileal isografts implanted under the kidney capsules of adult host rats and compared to the age-controlled intestine grown in situ. Studies were conducted on the 21st, 35th, 49th, and 63rd postconceptional days, corresponding to prenatal, suckling, weaning, and weaned rats. Substantial fatty acid esterification activity was found in prenatal jejunum but not in ileum. A proximal-distal gradient of fatty acid esterification was observed in all groups grown in situ, but not in isografts. The monoglyceride pathway (MG-P) accounted for about one-third of total fatty acid esterification (TFAE) in jejunum grown in situ and remained constant through the study. In the ileum, MG-P was the major esterification pathway during the first 4 postnatal weeks, but decreased progressively after weaning to become insignificant in adult rats. TFAE fell in the jejunal isografts, whereas it increased in the ileum. MG-P remained as the major pathway in the implanted jejunum and ileum. Our studies suggest that luminal contents are probably the most important modulator for the development and maintenance of intestinal fatty acid esterification, and "fetal programming" manifested by changes in fatty acid esterification mechanisms in the isografts is less important.

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