Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1987-8-5
pubmed:abstractText
Mucin secretion in situ from rat intestinal loops was promoted more effectively by dialysed crude cholera filtrate than by an equivalent amount of purified enterotoxin. The filtrate could be rendered inactive by incubation with mixed gangliosides or passage through a GM1-affinity column, which indicated that the secretory action of the filtrate depended upon its enterotoxin component. In an effort to explain the greater potency of the filtrate, we established the presence of a metalloproteinase in the filtrate and demonstrated that this enzyme was capable of degrading purified rat intestinal mucin. Sufficient degradation occurred to cause a substantial decrease in viscosity (57% in 120 min). Biochemical analysis of the mucin before and after exposure to filtrate revealed a rise in the combined percentage of serine, threonine and proline (53-58%), suggesting that poorly glycosylated areas (which are less abundant in these amino acids) were being partly removed from the mucin. The carbohydrate composition was essentially unaltered. Inhibition of the filtrate metalloproteinase by Zincov and alpha 2-macroglobulin significantly (P less than 0.005) reduced the ability of cholera filtrate to degrade mucin or to stimulate mucin secretion from rat intestinal slices in vitro. Purified cholera enterotoxin added to enterotoxin-depleted filtrate was a more potent secretagogue (secretory stimulant) in intestinal loops than an equivalent amount of enterotoxin alone. We therefore propose that mucin secretion induced by cholera filtrate is caused by cholera enterotoxin, but that degradation of the protective epithelial mucus layer by a constituent metalloproteinase may assist the toxin by allowing increased access to mucosal GM1 receptor sites.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
22
pubmed:volume
924
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
393-402
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1987
pubmed:articleTitle
Vibrio cholerae metalloproteinase degrades intestinal mucin and facilitates enterotoxin-induced secretion from rat intestine.
pubmed:publicationType
Journal Article, In Vitro