Regional Small-Intestinal Permeability in Vitro to Different-Sized Dextrans and Proteins in the Rat

Pantzar, N.; Weström, Björn; Luts, A.; Lundin, S.

doi:10.3109/00365529309096073

Cited by 53 publications

(45 citation statements)

References 31 publications

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“…Disruption of the mucosal barrier, or the movement of microand macromolecules from the lumen to the circulation across enterocytes, has been reported under various conditions [22]. Minimal but similar movement of the marker substance through the enteric mucosa of the normal dog was demonstrated in this study, as described in the normal rat intestine [23]. Pantzar et al, using the same Ussing chamber technique, demonstrated that 0.03-0.04% of the FITC-conjugated Dextran injected into the mucosal-side reservoir was recovered from the serosal-side solution after 60 min perfusion.…”

Section: Discussionsupporting

confidence: 48%

Effect of Ischemia on the Canine Large Bowel: A Comparison with the Small Intestine

Takeyoshi

Zhang

Nakamura

et al. 1996

Journal of Surgical Research

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Mucosal injury caused by ischemia and reperfusion has been well documented with the small intestine, but little is known about the colon. In the present study, the effect of warm and cold ischemia on the canine colon was studied and compared to that on the small intestine. After in situ flushing, the small intestine and the colon from six beagle dogs were removed and stored for 0.5, 1.5, and 3 hr at 37°C (warm ischemia) or for 1, 6, 12, 24, 36, and 48 hr at 4°C (cold ischemia). Electrophysiology, permeability, biochemistry, and histopathology of the specimens at each ischemic period and after reperfusion in the Ussing chamber were determined. Warm and cold ischemia induced durationdependent suppression of electrophysiology in both organs, but the colonic mucosa retained higher activity of absorptive enterocytes and cryptic cells than the small intestine. Only the colon showed increased permeability of FITC-conjugated Dextran from the mucosal surface to the submucosal layer after prolonged ischemia. Changes in adenine nucleotides and purine catabolites were not markedly different between the organs. Histopathologic abnormalities during ischemia and after reperfusion were more serious with the small intestine than with the colon. Compared to warm ischemia, hypothermia lessened or delayed these morphofunctional derangements in both organs, which became universally worsened after reperfusion. Colonic mucosa receives morphofunctional derangements from ischemia and reperfusion, but the severity of the damage was much less severe in the colon than in the small intestine.

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Section: Discussionsupporting

confidence: 48%

Effect of Ischemia on the Canine Large Bowel: A Comparison with the Small Intestine

Takeyoshi

Zhang

Nakamura

et al. 1996

Journal of Surgical Research

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“…where c i represents the concentration of the marker molecule present in the serosal half-cell (M) and c 0 represents the initial concentration of the same marker molecule in the mucosal half-cell (M) (18) . The apparent permeability coefficient (P app ) was calculated for the macromolecules FITC-dextran and ovalbumin by means of the formula:…”

Section: Calculationsmentioning

confidence: 99%

“…where dc/dt represents the change of serosal concentration in the 60 to 120 min period (M/s), V the volume in the half-cells (cm 3 ), c 0 the initial marker concentration in the mucosal half-cell (M), and A the area of exposed intestine in the Ussing chamber (cm 2 ) (18) .…”

Section: Calculationsmentioning

confidence: 99%

“…All intestinal segments were mounted in the chambers within 30 min after the intestine was collected. The intestinal segments were considered viable for a minimum of 2 h after mounted in the chambers (18) . At the start of the experiment, the buffer was exchanged to fresh buffer in the serosal half-cell, and test solution in the mucosal half-cell.…”

Section: Ussing Experiments and Analysesmentioning

confidence: 99%

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Chloroplast thylakoids reduce glucose uptake and decrease intestinal macromolecular permeability

et al. 2011

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Thylakoid membranes, derived from chloroplasts, have previously been shown to retard fat digestion and lower blood glucose levels after oral intake. The purpose of the present study was to investigate the effect of thylakoid membranes on the passage of methyl-glucose, dextran and ovalbumin over rat intestine in vitro using Ussing chambers. The results show that thylakoids retard the passage of each of the test molecules in a dose-dependent way. The thylakoids appear to be attached on the mucosal surface and a mechanism is suggested that the thylakoids delay the passage of the test molecules by sterical hindrance. The present results indicate that thylakoid membranes may be useful both to control intestinal absorption of glucose and to enhance the barrier function of the intestine.

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“…Insulin absorption appears to differ between intestinal regions because the protease content is much higher in the upper small intestine than in the descending small intestine (24). Furthermore, the permeability of macromolecular drugs is molecular weight-dependent passage over different regions of the small intestine (25). Therefore, the design of an optimal oral delivery system of insulin using a physical complex of CPPs depends on understanding the different effects of CPPs on the insulin absorption along the intestinal tract.…”

Section: Introductionmentioning

confidence: 99%

Region-Dependent Role of Cell-Penetrating Peptides in Insulin Absorption Across the Rat Small Intestinal Membrane

Khafagy

Iwamae

Kamei

et al. 2015

AAPS J

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Abstract. We have reported that the cell-penetrating peptide (CPP) penetratin acts as a potential absorption enhancer in oral insulin delivery systems and that this action occurs through noncovalent intermolecular interactions. However, the region-dependent role of CPPs in intestinal insulin absorption has not been clarified. To identify the intestinal region where CPPs have the most effect in increasing insulin absorption, the region-dependent action of penetratin was investigated using in situ closed intestinal loops in rats. The order of the insulin area under the insulin concentration-time curve (AUC) increase effect by L-penetratin was ileum>jejunum>duodenum>colon. By contrast, the AUC order after coadministration of insulin with D-penetratin was colon>duodenum≥jejunum and ileum. We also compared the effects of the L-and D-forms of penetratin, R8, and PenetraMax on ileal insulin absorption. Along with the CPPs used in this study, L-and D-PenetraMax produced the largest insulin AUCs. An absorption study using ilea pretreated with CPPs showed that PenetraMax had no irreversible effect on the intestinal epithelial membrane. The degradation of insulin in the presence of CPPs was assessed in rat intestinal enzymatic fluid. The half-life (t 1/2 ) of insulin increased from 14.5 to 23.7 and 184.7 min in the presence of L-and D-PenetraMax, respectively. These enzymatic degradation-resistant effects might contribute partly to the increased ileal absorption of insulin induced by D-PenetraMax. In conclusion, this study demonstrated that the ability of the L-and D-forms of penetratin to increase intestinal insulin absorption was maximal in the ileum and the colon, respectively, and that D-PenetraMax is a powerful but transient enhancer of oral insulin absorption.

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Regional Small-Intestinal Permeability in Vitro to Different-Sized Dextrans and Proteins in the Rat

Cited by 53 publications

References 31 publications

Effect of Ischemia on the Canine Large Bowel: A Comparison with the Small Intestine

Effect of Ischemia on the Canine Large Bowel: A Comparison with the Small Intestine

Chloroplast thylakoids reduce glucose uptake and decrease intestinal macromolecular permeability

Region-Dependent Role of Cell-Penetrating Peptides in Insulin Absorption Across the Rat Small Intestinal Membrane

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