PMID- 2383653
OWN - NLM
STAT- MEDLINE
DCOM- 19900918
LR  - 20220309
IS  - 0006-4971 (Print)
IS  - 0006-4971 (Linking)
VI  - 76
IP  - 4
DP  - 1990 Aug 15
TI  - Factor IX is activated in vivo by the tissue factor mechanism.
PG  - 731-6
AB  - Despite significant progress in elucidating the biochemistry of the hemostatic 
      mechanism, the process of blood coagulation in vivo remains poorly understood. 
      Factor IX is a vitamin K-dependent glycoprotein that can be activated by factor 
      XIa or the factor VII-tissue factor complex in vitro. To investigate the role of 
      these two pathways in factor IX activation in humans, we have developed a 
      sensitive procedure for quantifying the peptide that is liberated with the 
      generation of factor IXa. The antibody population used for the immunoassay was 
      raised in rabbits and chromatographed on a factor IX-agarose immunoadsorbent to 
      obtain antibody populations with minimal intrinsic reactivity toward factor IX. 
      We determined that the mean level of the factor IX activation peptide (FIXP) in 
      normal individuals under the age of 40 years was 203 pmol/L and that levels 
      increased significantly with advancing age. The mean concentration of FIXP was 
      markedly reduced to 22.7 pmol/L in nine patients with hereditary factor VII 
      deficiency (factor VII coagulant activity less than 7%) but was not significantly 
      different from normal controls in nine subjects with factor XI deficiency (factor 
      XI coagulant activity less than 8%). These data indicate that factor IXa 
      generation in vivo results mainly from the activity of the tissue factor 
      mechanism rather than the contact system (factor XII, prekallikrein, high 
      molecular-weight kininogen, factor XI). Our results may also help to explain the 
      absence of a bleeding diathesis in many patients with deficiencies of the contact 
      factors of coagulation.
FAU - Bauer, K A
AU  - Bauer KA
AD  - Charles A. Dana Research Institute, Boston, MA.
FAU - Kass, B L
AU  - Kass BL
FAU - ten Cate, H
AU  - ten Cate H
FAU - Hawiger, J J
AU  - Hawiger JJ
FAU - Rosenberg, R D
AU  - Rosenberg RD
LA  - eng
GR  - P01 AG 00599/AG/NIA NIH HHS/United States
GR  - P01 HL 33014/HL/NHLBI NIH HHS/United States
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - Blood
JT  - Blood
JID - 7603509
RN  - 0 (Immune Sera)
RN  - 9001-25-6 (Factor VII)
RN  - 9001-28-9 (Factor IX)
RN  - 9035-58-9 (Thromboplastin)
RN  - EC 3.4.21.27 (Factor XIa)
SB  - IM
MH  - Adult
MH  - Aged
MH  - Aged, 80 and over
MH  - Factor IX/immunology/*physiology
MH  - Factor VII/physiology
MH  - Factor XI Deficiency/genetics/physiopathology
MH  - Factor XIa/physiology
MH  - Humans
MH  - Immune Sera/immunology
MH  - Male
MH  - Middle Aged
MH  - Radioimmunoassay
MH  - Thromboplastin/*physiology
EDAT- 1990/08/15 00:00
MHDA- 1990/08/15 00:01
CRDT- 1990/08/15 00:00
PHST- 1990/08/15 00:00 [pubmed]
PHST- 1990/08/15 00:01 [medline]
PHST- 1990/08/15 00:00 [entrez]
AID - S0006-4971(20)82448-3 [pii]
PST - ppublish
SO  - Blood. 1990 Aug 15;76(4):731-6.