Linked Life Data

12062545

Source:http://linkedlifedata.com/resource/pubmed/id/12062545

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2002-6-13
pubmed:abstractText
Protein S (PS) is a vitamin K-dependent plasma protein and serves as a cofactor for the anticoagulant activities of activated protein C (APC). We investigated the effects of different PS concentrations on prothrombin activation and thrombin generation in cord and adult plasma containing APC and different amounts of alpha 2-macroglobulin (a2-M). Prothrombin activation was assessed by monitoring the time-course of prothrombin fragment 1+2 (F1+2) generation. Thrombin generation curves were determined by means of a subsampling technique using the chromogenic substrate S-2238. We demonstrate a dose-dependent inhibition of the anticoagulant action of PS by a2-M: suppression of F1+2 and thrombin generation due to addition of PS was stronger in plasma containing low amounts of a2-M than in plasma with elevated a2-M levels. Since no complex formation between a2-M and PS was observed by means of SDS-PAGE, we attribute decreased anticoagulant action of PS at high a2-M levels to enhanced complex formation between APC and a2-M. Thereby, APC is subtracted from its cofactor PS, resulting in suppressed formation of the anticoagulant APC/PS complex. Thus, our data suggest that a2-M, besides its well-known anticoagulant effects, also acts as a procoagulant by suppressing the formation of the anticoagulant APC/PS complex. Our findings have implications particularly on thrombin generation and inhibition in cord plasma, since a2-M levels in newborns are elevated over adult values and the antithrombotic APC/PS pathway is up-regulated at birth. Therefore, elevated levels of a2-M might restrict the up-regulation of the APC/PS pathway.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0049-3848
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
105
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
433-9
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Alpha 2-macroglobulin enhances prothrombin activation and thrombin potential by inhibiting the anticoagulant protein C/protein S system in cord and adult plasma.
pubmed:affiliation
Ludwig Boltzmann Research Institute for Pediatric Hemostasis and Thrombosis, Graz, Austria. gerhard.cvirn@klinikum-graz.at
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't