1. In people acclimated to high altitudes, the concentration of 2,3-diphosphoglycerate (2,3-DPG) in the blood is increased, which allows these individuals to deliver a larger amount of oxygen to tissues under conditions of lower oxygen tension.
Initially given high dose O2 through mask
Electron transport
Because there are many more oxygen molecules present in a given volume when under pressure, hyperbaric oxygen dissolves in the blood in far greater amounts enabling it to be transported to the cells. Hyperbaric oxygen (HBO) also helps rid haemoglobin of the tenacious CO molecules, freeing it up for normal use once more. The actual amount of oxygen molecules at a pressure of 3ata (20msw) in a fixed volume is equal to 3 times the amount at the surface. In cases of carbon monoxide poisoning, it normally takes over four hours for the amount of CO in the body to fall by one half, during which time the tissues are hypoxic due to replacement of O2Hb with COHb. Hyperbaric oxygen at 3ata reduces this to 20 minutes, during which time the extra oxygen dissolved in the blood alleviates hypoxia.

2. Prostaglandins
act in a manner similar to that of hormones, by stimulating target cells into action.
differ from hormones in that they act locally, near their site of synthesis, and they are metabolized very rapidly
the same prostaglandins act differently in different tissues

4. Hemostasis & Thrombosis: Hemophilia
Beth A. Bouchard
BIOC 212: Biochemistry of Human Disease
Spring 2005

6. HEMOSTASIS 1). INITIATION
Vessel wall – endothelial cells and subendothelial components
2). LOCALIZATION
Platelets – circulating cellular elements
3). PROPAGATION/AMPLIFICATION
Plasma coagulation proteins (factors)
4). TERMINATION
Plasma coagulation protein inhibitors
5). ELIMINATION
Fibrinolytic system

8. BLOOD COAGULATION

10. BLOOD COAGULATION (CONT.)
Deficiencies in all of the factors, except factor XII, lead to a bleeding tendency in the affected individual
Described as a ‘waterfall’ or ‘cascade’ sequence of zymogen (pro-enzyme) to enzyme conversions, with each enzyme activating the next zymogen in the seqeunce
Activated factor enzymes are designated with an “a”, e.g. factor Xa

11. Common constituents of coagulation complexes
Vitamin K-dependent (VKD) zymogen
Ca2+
Protein cofactor
Appropriate membrane surface
- activated platelets (VIIIa/IXa complex, Va/Xa complex)
subendothelial cells, typically fibroblasts (TF/VIIa complex)

13. Common constituents of coagulation complexes
Vitamin K-dependent (VKD) zymogen
Ca2+
Protein cofactor
Appropriate membrane surface
- activated platelets (VIIIa/IXa complex, Va/Xa complex)
subendothelial cells, typically fibroblasts (TF/VIIa complex)

14. Functional Domains of the Vitamin K-
dependent Zymogens

15. Gamma (g)-carboxyglutamic acid

16. VITAMIN K
Group of related, fat soluble compounds, which differ in the number of side-chain isoprenoid units
Plant derived (vitamin K1) and synthesized by intestinal bacteria (vitamin K2)
The reduced form of vitamin K2 (vitamin KH2) is required for the post-translational, gamma-carboxylation of several proteins involved in blood clotting

17. Formation of Gla residues subsequent to
protein synthesis (post-translational)

18. Vitamin K deficiency
Deficiency of vitamin K is rare because of its wide distribution in nature, and its production by intestinal bacteria
Found in individuals with liver disease and fat malabsorption - it is associated with bleeding disorders
Newborn infants (especially preemies) are also at risk
- Placenta is insufficient in the transfer of maternal vitamin K
- Concentration of circulating vitamin K drops immediately after birth, and it recovers upon absorption of food
- Gut of the newborn is sterile
Thus, newborns are given an injection of vitamin K following birth.

19. Common constituents of coagulation complexes
Vitamin K-dependent (VKD) zymogen
Ca2+
Protein cofactor
Appropriate membrane surface
- activated platelets (VIIIa/IXa complex, Va/Xa complex)
subendothelial cells, typically fibroblasts (TF/VIIa complex)

20. 1 300,000 30 300 -Thrombin Prothrombin Relative Rate of Prothrombin
Prothrombinase
Components
Relative Rate
of Prothrombin
Activation
FXa 1
Prothrombin
Ca2+
FVa HC
FVa LC
Ca2+
FXa
FVa HC
FVa LC
300,000
Ca2+
FXa 30
FXa
300
FVa HC
FVa LC
Ca2+
Relevance of complex formation and its constituents

21. Common constituents of coagulation complexes
Vitamin K-dependent (VKD) zymogen
Ca2+
Protein cofactor
Appropriate membrane surface
- activated platelets (VIIIa/IXa complex, Va/Xa complex)
subendothelial cells, typically fibroblasts (TF/VIIa complex)
** Express anionic phospholipids and membrane receptors for coagulation proteins.
In platelets, the expression of this membrane surface is activation-dependent.

22. Extrinsic Tenase Intrinsic Tenase Thrombin Prothrombinase FVIIa FIXa
Ca2+
FVIIa TF
Extrinsic Tenase
Ca2+
FIXa
FVIIIa
Intrinsic Tenase
Thrombin
Cleaves Fibrinogen
Activates Platelets
Activates procofactors (FV and FVIII)
Activates zymogens (FVII, FXI and FXIII)
FXa
FIXa
Prothrombinase
Ca2+
FXa
FVa HC
FVa LC
IIa

24. Intrinsic Pathway of Blood Coagulation
No factors extrinsic to the blood are involved
Clinical test to assess the functionality of this pathway is the activated partial thromboplastin time (aPTT)
Kaolin and cephalin are added to the test plasma sample
The normal range is ~30 – 50 seconds (varies slightly depending on the laboratory)
Prolongations in the aPTT are observed in deficiencies of factors XI, IX, VIII, X, and V, prothrombin, or fibrinogen.
Used to test for common congenital hemophilias (deficiencies in IX, VIII, or XI) and to monitor heparin treatment

25. Extrinsic Pathway of Blood Coagulation
Extrinsic refers to tissue factor, which is expressed on subendothelial cells
Clinical test to assess the functionality of this pathway is the prothrombin time (PT)
Lipidated tissue factor is added to test plasma sample
The normal range is ~10-15 seconds (varies slightly depending on the laboratory)
Prolongations in the PT are observed in deficiencies of factors VII, X, V, prothrombin, or fibrinogen.
Used to test for the rare congenital deficiencies in these factors: More often it is used to diagnose acquired bleeding disorders resulting from vitamin K deficiency, oral anticoagulants (e.g. warfarin), and liver disease

26. Thrombin Time (TT) In this test, thrombin is added to plasma
The normal range is ~10-15 seconds (varies slightly depending on the laboratory)
Prolongations in the TT are observed in congenital fibrinogen deficiency or acquired fibrinogen deficiency resulting from consumption of fibrinogen in DIC (disseminated intravascular coagulation), or may occur following treatment with fibrinolytic drugs

27. Hemophilias A and B
Hemophilias A and B are cause by deficiencies in factors VIII or IX, respectively
Affect ~1 in 10,000 males
Inherited as a recessive X-linked trait (Mom would be an unaffected carrier)
Treated by administration of factor VIII or factor IX concentrates
Recombinant factor VIII or XI
Gene therapy trials

28. HEMOSTASIS (CONT.) 1). INITIATION
Vessel wall – endothelial cells and subendothelial components
2). LOCALIZATION
Platelets – circulating cellular elements
3). PROPAGATION/AMPLIFICATION
Plasma coagulation proteins (factors)
4). TERMINATION
Plasma coagulation protein inhibitors
5). ELIMINATION
Fibrinolytic system

29. INHIBITORS

30. INHIBITORS (cont.)

31. FIBRINOLYSIS

32. FIBRINOLYSIS (CONT.)

33. Bleeding disorders can span the spectrum from weeping blood vessels to full-fledged internal and external hemorrhage
Hemorrhage
Genetic defects:
platelet abnormalities
blood vessel wall abnormalities
clotting factor deficiencies (hemophilias)
excess clot breakdown (fibrinolysis)
Acquired defects:
liver disease (site of clotting factor synthesis)
vitamin K deficiency
autoimmune disease (platelet destruction)
trauma

34. Treated by factor replacement
Bleeding disorders can span the spectrum from weeping blood vessels to full-fledged internal and external hemorrhage
Hemorrhage
Treated by factor replacement

35. Thrombosis can be manifested as a transient, short-term or episodic event in individuals with chronic or recurring clotting. It is the major cause of both stroke and heart attacks.
Thrombosis
Genetic defects:
clotting factor INHIBITOR deficiencies
decreased fibrinolysis
Acquired defects:
atherosclerosis

37. Antithrombotic Attributes of Vascular
Endothelium

38. Pharmacologic Approaches to Prevent
Thrombosis
Antiplatelet agents - block activation, aggregation or intraplatelet agonist synthesis
Effective anticoagulant therapy includes both
antiplatelet and antithrombin agents

39. Blood “thinners” - coumadin (warfarin): inhibition of “gla” formation
in the liver
Coumadin blocks reformation of reduced vitamin K, which essentially stops the post-translational modification of the glutamic acid residues at the amino-termini of the VKDP’s, since vitamin K is oxidized during the reaction.

40. Blood “thinners” - heparin: potent cofactor for ATIII-catalyzed
inhibition of procoagulant serine proteases

42. Snakes
Leeches
Blood-sucking Insects