Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1985-3-26
pubmed:abstractText
The pharmacokinetics of heparin differ markedly from those of its fractions both in man and in experimental animal models. The route of administration determines the relative availability of different molecular species that exert the anti-Xa, anti-IIa, fibrinopeptide A generation inhibiting actions and the release of tissue plasminogen activator-like activity from the endothelial cell lining. The bioavailability of heparin fractions has proved to be much greater than heparin after subcutaneous or intraperitoneal administration. Most of the low molecular weight heparin fractions exhibit sustained antiprotease and antithrombotic actions. The pharmacokinetics of the specific anti-IIa and anti-Xa actions of heparin and its fractions is dependent on the molecular composition of these agents. Even if the fractions are standardized for identical potencies by the in vitro assays, the elimination rate of anti-Xa and anti-IIa actions are significantly different for each fraction. The antithrombotic actions of heparin and its fractions also vary widely in the rabbit stasis thrombosis model. Different fractions show variable antithrombotic actions against defined thrombogenic challenges. Moreover, selection and potency of a thrombogenic agent is of crucial importance in these studies. The primate (Macaca mulatta) model offers a useful preclinical model for the pharmacologic evaluation of the low molecular heparin fractions. Since the coagulation system and heparinizability index of this model approximate a human response, the data may be used to reflect therapeutic and prophylactic responses, as well as to assess toxic effects, such as bleeding.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0094-6176
pubmed:author
pubmed:issnType
Print
pubmed:volume
11
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
56-74
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:3883500-Animals, pubmed-meshheading:3883500-Biological Availability, pubmed-meshheading:3883500-Bleeding Time, pubmed-meshheading:3883500-Chemical Phenomena, pubmed-meshheading:3883500-Chemistry, pubmed-meshheading:3883500-Disease Models, Animal, pubmed-meshheading:3883500-Factor X, pubmed-meshheading:3883500-Factor Xa, pubmed-meshheading:3883500-Fibrinopeptide A, pubmed-meshheading:3883500-Heparin, pubmed-meshheading:3883500-Humans, pubmed-meshheading:3883500-Kinetics, pubmed-meshheading:3883500-Macaca mulatta, pubmed-meshheading:3883500-Molecular Weight, pubmed-meshheading:3883500-Oligosaccharides, pubmed-meshheading:3883500-Partial Thromboplastin Time, pubmed-meshheading:3883500-Polymers, pubmed-meshheading:3883500-Prothrombin, pubmed-meshheading:3883500-Rabbits, pubmed-meshheading:3883500-Structure-Activity Relationship, pubmed-meshheading:3883500-Thrombosis
pubmed:year
1985
pubmed:articleTitle
Studies on the antithrombotic effects and pharmacokinetics of heparin fractions and fragments.
pubmed:publicationType
Journal Article, Comparative Study, Review