Biochemistry of Blood Elements

Vladimíra Kvasnicová

The figure is found at http://www.biosbcc.net/doohan/sample/htm/Blood%20cells.htm (March 2007)

Blood Elements Count

erythrocytes 4 - 6 x 106 / l

leukocytes 4 - 9 x 103 / l

neutrophils 47 - 75 %eosinophils 1 - 4 %basophils 0 - 1 %lymphocytes 23 - 45 %monocytes 2 - 11 %

thrombocytes 150 - 400 x 103 / l

Red Blood Cells(erythrocytes)

The figure is found at http://www.vghtpe.gov.tw/~hema/hematopoitic%20cell%20differentiation/RBC.htm (March 2007)

Red Blood Cells(erythrocytes)

1. Function erythrocyte as a bag for hemoglobin

O2 → transport, reactive oxygen species (ROS)

CO2 → transport, formation of HCO3-

H+ → transport, maintaining pH(35% of blood buffering capacity)

Red Blood Cells(erythrocytes)

2. Structure large surface

(diffusion of gases)

cytoskeletal proteins (elasticity)

membrane as an osmometer

(Na+/K+-ATPase)

The figure is found at http://www.biosbcc.net/doohan/sample/htm/Blood%20cells.htm (March 2007)

The figure is found at http://www.vet.purdue.edu/depts/bms/nour/bms520/content/blood/b9.htm (March 2007)

• hemolysis(blood,

plasma)

What happens to red blood cells when placed in hypotonic, hypertonic, and

isotonic solutions?

• osmolarity(285 mosmol/l)

• acanthocytes

The figures are found at http://www.wadsworth.org/chemheme/heme/microscope/pix/spherocytes_nw.jpg and http

://www.mie.utoronto.ca/labs/lcdlab/biopic/fig/4.23b.jpg (March 2007)

Red Blood Cells(erythrocytes)

membrane and cytoskeletal

proteins

hereditary spherocytos

is

Red Blood Cells(erythrocytes)

3. membrane transporters Na+/K+-ATPase (active transport)

GLUT-1 (insulin independent)

anion exchanger = band 3 protein (Cl-/HCO3-)

4. membrane antigens blood groups

The figure is found at http://www.life.umd.edu/classroom/bsci422/mosser/ABO.gif (March 2007)

ABO system

Red Blood Cells(erythrocytes)

5. metabolism glucose is the main fuel

90% anaerobic glycolysis(ATP, lactate: Cori cycle; 2,3-BPG)

10% hexose monophosphate pathway(NADPH)

enzyme defects : * glucose-6-P dehydrogenase

* pyruvate kinase

→ hemolytic anemia

Red Blood Cells(erythrocytes)

5. other important enzymes carbonate dehydratase (= carbonic

anhydrase, CA)

methemoglobin reductase

superoxide dismutase

catalase antioxidative system

glutathione peroxidase

glutathione reductase

Red Blood Cells(erythrocytes)

superoxide dismutase (SOD)

O2• + O2

• + 2 H+ H2O2 + O2

catalase (CAT)

H2O2 + H2O2 2 H2O + O2

Red Blood Cells(erythrocytes)

glutathione peroxidase (GPx)

2 GSH + H2O2 GS-SG + 2 H2O

2 GSH + R-O-OH GS-SG + H2O + ROH

The figure is found at http://www.cs.stedwards.edu/chem/Chemistry/CHEM47/ResMethods2003/graphics/?M=A

(March 2007)

glutathione = „redox buffer“

The figure is found at http://www.med.unibs.it/~marchesi/ppp.html (March 2007)

Hexose Monophosphate

Pathway

glutathione reductase

GS-SG + NADPH+H+

2 GSH + NADP+

The figure is found at http://www.vrp.com/newsimages/march04Fig1.jpg (March 2007)

2

Glutathione system

NADPH+H+

The figure is found at http://www.biosbcc.net/doohan/sample/htm/Blood%20cells.htm (March 2007)

Red Blood Cells(erythrocytes)

6. Erythropoesis

The figure is found at http://faculty.ccp.edu/dept/biol/All_five_leukocytes.jpg (March 2007)

White Blood Cells

(leukocytes)

White Blood Cells(leukocytes)

Classification• granulocytes

neutrophils (phagocytosis)eosinophils (alergy, parasites)basophils (alergy)

• agranulocytesmonocytes → macrophages lymphocytes (B, T)

Reactive oxygen and nitrogen species

in blood elements

ERYTHROCYTESenzymes for deactivation of ROS formed

from high content of oxygen found in the cells

PHAGOCYTESenzymes for production of ROS and

RNS to destroy particles in phagosomes

White Blood Cells(leukocytes)

Neutrophils (microphages)

• high content of lysosoms (hydrolytic enzymes)

• few mitochondria

• glucose dependent: NADPH production

• NADPH is used for production of reactive oxygen species → they kill bacteria

• after activation: RESPIRATORY BURST= increased consumption of O2 and glucose

The figure is found at http://courses.washington.edu/conj/bloodcells/radicals.gif (March 2007)

Reactive oxygen species (ROS)produced by neutrophils

ClO-

White Blood Cells(leukocytes)

The figure is found at http://www.pigur.co.il/imgpku/no_synthesis.gif (March 2007)

NO· is a reactive nitrogen species used by phagocytes

iNOS

White Blood Cells(leukocytes)

proteolytic enzymes /elastase

collagenase

gelatinase

kathepsin G

protease inhibitors

1-protease inhibitor(= 1-antitrypsin)

1-antichymotrypsin

2-macroglobulin

produced by phagocytes = plasma proteins

Their ratio affects an extent of inflammation!

The figures are found at http://life.nthu.edu.tw/~lslpc/BioPhyTalk/heparin01.jpg and http://www.nottingham.ac.uk/~mqzwww/images/histamine.gif (March 2007)

Basofils

contain heparin and histamine

The figure is found at http://www-immuno.path.cam.ac.uk/~immuno/part1/lec06/ab12.gif (March 2007)

B-lymphocytes

produce antibodies (= immunoglobulins, -globulins)

( or )

(, , , , )

The figure is found at http://image.bloodline.net/stories/storyReader$590 (March 2007)

Platelets(thrombocytes

)

The figure is found at http://www.biosbcc.net/doohan/sample/htm/Hemostasis.htm (March 2007)

Platelets(thrombocytes)

participate in hemostasis

• adhesion: glycosaminoglycans and glycoproteins (hyalomera)

• activation: free collagen, thrombin, ADP, TxA2, serotonin• contraction of thrombus: Ca2+, glycogen, ATP