Effect of alcohols on gastric and small intestinal apical membrane integrity and fluidity
Duodenal and jejunal brush border membrane vesicle integrity was studied after in vitro treatment of rabbit tissue with ethyl, benzyl or octyl alcohol. The effects of the alcohols on gastric parietal cell apical and microsomal membrane vesicle integrity was also studied. Membrane vesicle integrity w...
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Published in | Gut Vol. 29; no. 12; pp. 1648 - 1655 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
London
BMJ Publishing Group Ltd and British Society of Gastroenterology
01.12.1988
BMJ BMJ Publishing Group LTD |
Subjects | |
Online Access | Get full text |
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Summary: | Duodenal and jejunal brush border membrane vesicle integrity was studied after in vitro treatment of rabbit tissue with ethyl, benzyl or octyl alcohol. The effects of the alcohols on gastric parietal cell apical and microsomal membrane vesicle integrity was also studied. Membrane vesicle integrity was determined from the enclosed volume of the vesicle preparations, measured as [14C]glucose space at equilibrium. Exposure of vesicles to the three alcohols caused concentration dependent decreases in enclosed volume. The rank order of potency of the alcohol was octyl greater than benzyl greater than ethyl. Concentrations greater than or equal to 10 mM benzyl alcohol significantly reduced the enclosed volume of duodenal or jejunal vesicles; jejunal vesicles were disrupted by 625 mM ethanol, whereas 2 M ethanol was required to disrupt the duodenal vesicles. Gastric apical membrane integrity was reduced with 0.25 M ethanol, the vesicles being approximately an order of magnitude more sensitive to ethanol than gross estimates of gastric mucosal damage, but 1 M ethanol was required to significantly damage gastric microsomes. All concentrations of benzyl or octyl alcohol tested (greater than or equal to 5 mM) reduced the enclosed volume of both gastric apical membrane vesicles and gastric microsomes. As determined by shrink-swell techniques, benzyl alcohol permeated duodenal vesicles at a faster rate than NH4Cl (apparent rate constant of 9.89 (0.71) X 10(-3)s-1 compared with 4.48 (0.23) X 10(-3)s-1). Therefore, reductions in enclosed volume in response to alcohol treatment could not be explained by alcohol induced osmotic shrinkage. The enclosed volume of the vesicles after alcohol treatment was negatively correlated with membrane fluidity suggesting a common causal effect, the increased fluidity increasing membrane fragility. Duodenal vesicles were more resistant to disruption by the alcohols compared with gastric and jejunal vesicles. |
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Bibliography: | ark:/67375/NVC-HJWN4BS1-D href:gutjnl-29-1648.pdf istex:948D5B12275932949CE217705B6F4D93A9850746 local:gutjnl;29/12/1648 PMID:3220304 ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0017-5749 1468-3288 1458-3288 |
DOI: | 10.1136/gut.29.12.1648 |