Linked Life Data

2881583

Source:http://linkedlifedata.com/resource/pubmed/id/2881583

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1987-5-13
pubmed:abstractText
Mg2+-dependent activity of intestinal brush border guanylate cyclase was stimulated 4-5-fold by 50-100 microM hemin. Higher concentrations were inhibitory. In the presence of 25% dimethyl sulfoxide, which stimulated activity 9-times, 50 microM hemin further increased activity 1.7-fold. However, when activity was stimulated 32-fold by the Escherichia coli heat-stable enterotoxin, or 26-fold by Lubrol PX, hemin produced only concentration-dependent inhibition. The first type of activation was more sensitive to hemin than the second. Reduction of hemin by dithiothreitol eliminated stimulation of basal activity, while inhibition of Lubrol PX-stimulated activity remained. Protoporphyrin IX also had no effect on basal activity, however, it inhibited enterotoxin- and Lubrol PX-stimulated activities similarly, but only to half the extent of hemin. Substitution of Mn2+ for Mg2+ elevated basal activity 15-fold, and this Mn2+-dependent activity was inhibited by hemin. Mn2+-dependent activity was stimulated (43%) by enterotoxin, however, the stimulated activity was more sensitive to hemin inhibition than the basal Mn2+-dependent activity and both inhibition curves were congruent above 50 microM hemin. Hemin inhibition of Lubrol PX-stimulated activity was much less with Mn2+ than with Mg2+. These results were interpreted as suggesting two sites of hemin inhibition; on an inhibitory regulator and on the enzyme. We also found that the secretory effect of enterotoxin in the suckling mouse bioassay was reduced 56% by the oral administration of hemin.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Bacterial Toxins, http://linkedlifedata.com/resource/pubmed/chemical/Dimethyl Sulfoxide, http://linkedlifedata.com/resource/pubmed/chemical/Dithiothreitol, http://linkedlifedata.com/resource/pubmed/chemical/Enterotoxins, http://linkedlifedata.com/resource/pubmed/chemical/Guanylate Cyclase, http://linkedlifedata.com/resource/pubmed/chemical/Heme, http://linkedlifedata.com/resource/pubmed/chemical/Hemin, http://linkedlifedata.com/resource/pubmed/chemical/Manganese, http://linkedlifedata.com/resource/pubmed/chemical/Nitric Oxide, http://linkedlifedata.com/resource/pubmed/chemical/Polyethylene Glycols, http://linkedlifedata.com/resource/pubmed/chemical/Porphyrins, http://linkedlifedata.com/resource/pubmed/chemical/Protoporphyrins, http://linkedlifedata.com/resource/pubmed/chemical/heat stable toxin (E coli), http://linkedlifedata.com/resource/pubmed/chemical/lubrol, http://linkedlifedata.com/resource/pubmed/chemical/protoporphyrin IX
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
2
pubmed:volume
928
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
83-91
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1987
pubmed:articleTitle
Regulation of intestinal mucosa guanylate cyclase by hemin, heme and protoporphyrin IX.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't