Linked Life Data

2052204

Source:http://linkedlifedata.com/resource/pubmed/id/2052204

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1991-7-25
pubmed:abstractText
Rats have very high endogenous levels of serum carboxylesterase (CAE) compared to primates. This difference accounts for the lower sensitivity of rats to toxic organophosphates, which interact with CAE instead of the more critical acetylcholinesterase. Pretreatment of rats with CAE inhibitors potentiates the effects of organophosphates. In this study, the effects of three putative CAE inhibitors, 2-(o-Cresyl)-4H-1:3:2-benzodioxaphosphorin-2-oxide (CBDP), bis-p-nitrophenyl-phosphate (BNPP), and tetraisopropyl pyrophosphoramide (Iso-OMPA), on the hydrolysis of several commercially available substrates were determined. Respective kinetic constants Km and Vmax were derived and effects of inhibitors compared using saturating amounts of substrate. Data presented here indicate significant differences in substrate affinity (Km), reactivity (Vmax), as well as effects of inhibitors. CBDP inhibits hydrolysis of specific naphthyl and paranitrophenyl esters at relatively low concentrations (1-10 microM). In contrast, significantly higher concentrations (mM) of BNPP and Iso-OMPA were required for inhibition of serum esterase activity. Of the inhibitors tested, Iso-OMPA in general exhibited the smallest inhibitory effect on ester hydrolysis. Although inhibition of hydrolysis of specific paranitrophenyl and naphthyl esters occurred in the presence of similar amounts of CBDP, the degree of inhibition differed significantly (50-75% vs. greater than 90%, respectively). These data suggest that there exists in rat serum, a pool of naphthyl ester esterase activity that is very sensitive ex vivo (greater than 90% inhibition) to CBDP and may be very useful in validating a rodent model for soman toxicity.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0149-7634
pubmed:author
pubmed:issnType
Print
pubmed:volume
15
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
85-8
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Effects of three reputed carboxylesterase inhibitors upon rat serum esterase activity.
pubmed:affiliation
Brain Research Laboratory of Biochemistry, University of Texas, San Antonio 78285.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.