PMID- 1329921
OWN - NLM
STAT- MEDLINE
DCOM- 19921223
LR  - 20190704
IS  - 0007-1048 (Print)
IS  - 0007-1048 (Linking)
VI  - 82
IP  - 2
DP  - 1992 Oct
TI  - Inhibition of thrombin generation by heparin and low molecular weight (LMW) 
      heparins in the absence and presence of platelet factor 4 (PF4).
PG  - 406-13
AB  - The ability of several low molecular weight (LMW) heparins and unfractionated 
      heparin (UFH) to inhibit thrombin generation, and their anti-Xa and anti-IIa 
      activities, were measured in the absence and presence of platelet factor 4 (PF4). 
      The LMW heparins studied were 2-5 times less potent, on a weight basis, than UFH 
      as inhibitors of thrombin generation in platelet-poor plasma; the inhibition of 
      thrombin generation by LMW heparins correlated better with their anti-IIa 
      activity (r = 0.98) than with their anti-Xa activity (r = 0.69). At low 
      concentrations of PF4, the activity of LMW heparins in the thrombin generation 
      test was neutralized less than that of UFH, but at higher PF4 concentrations all 
      their activities could be neutralized except in anti-Xa assays. These 
      observations support the hypothesis that anti-IIa activity is important for 
      inhibition of thrombin generation by LMW heparins in vitro. However, when all the 
      anti-IIa activity of LMW heparins was neutralized by PF4, considerable inhibitory 
      activity remained in thrombin generation and anti-Xa assays, indicating that a 
      portion of the anti-Xa activity of LMW heparins also contributes towards 
      inhibition of thrombin generation.
FAU - Padilla, A
AU  - Padilla A
AD  - Division of Haematology, National Institute for Biological Standards and Control, 
      Potters Bar, Herts.
FAU - Gray, E
AU  - Gray E
FAU - Pepper, D S
AU  - Pepper DS
FAU - Barrowcliffe, T W
AU  - Barrowcliffe TW
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - England
TA  - Br J Haematol
JT  - British journal of haematology
JID - 0372544
RN  - 0 (Factor Xa Inhibitors)
RN  - 0 (Heparin Antagonists)
RN  - 0 (Heparin, Low-Molecular-Weight)
RN  - 37270-94-3 (Platelet Factor 4)
RN  - 9001-26-7 (Prothrombin)
RN  - 9002-04-4 (Factor IIa)
RN  - 9005-49-6 (Heparin)
RN  - EC 3.4.21.5 (Thrombin)
SB  - IM
MH  - Factor Xa Inhibitors
MH  - Heparin/*pharmacology
MH  - Heparin Antagonists/pharmacology
MH  - Heparin, Low-Molecular-Weight/antagonists & inhibitors/*pharmacology
MH  - Humans
MH  - Molecular Weight
MH  - Platelet Factor 4/*pharmacology
MH  - Prothrombin/antagonists & inhibitors
MH  - Thrombin/*antagonists & inhibitors
EDAT- 1992/10/01 00:00
MHDA- 1992/10/01 00:01
CRDT- 1992/10/01 00:00
PHST- 1992/10/01 00:00 [pubmed]
PHST- 1992/10/01 00:01 [medline]
PHST- 1992/10/01 00:00 [entrez]
AID - 10.1111/j.1365-2141.1992.tb06437.x [doi]
PST - ppublish
SO  - Br J Haematol. 1992 Oct;82(2):406-13. doi: 10.1111/j.1365-2141.1992.tb06437.x.