Biochemical features of blood cells

• The basic function and composition of blood is 8% of an adult’s body weight, with females having 4-5 litres and males having 5-6 litres.
• The temperature of blood is 38 degrees Celcius and the pH is 7.35-7.45.
• The viscosity of blood is 4.5-5.5 times as viscous as water.
• The composition of blood includes White Blood Cells (WBCs), Leucocytes, Granulocytes, Agranulocytes, Neutrophils, Lymphocytes, Eosinophils, Monocytes, and Basophils.
• Red Blood Cells (also called erythrocytes) are formed elements of blood, with a shape of a biconcave disc, a volume of 80-100 fL, and an area of about 160 μm2.
• The major functions of Red Blood Cells (RBCs) are delivering oxygen to the tissues and disposal of carbon dioxide and protons formed by the tissue metabolism.
• Red Blood Cell production, or Erytropoiesis, is a dynamic process that originates from pluripotent stem cells.
• The Red Blood Cell Maturation involves six stages of maturation in the red cell series, with each normoblast undergoing four more cycles of cell division.
• During the last division of the Red Blood Cell Maturation, the nucleus is extruded, resulting in a cell called a Reticulocyte.
• Reticulocytes still contain ribosomes and mRNA and are capable of synthesizing hemoglobin.
• Reticulocytes are released from the bone marrow and circulate for 1 to 2 days.
• Reticulocytes mature in the spleen, where the ribosomes and mRNA are lost.
• The Red Blood Cells are under the control of erythropoietin (EPO), a hormone produced by the kidneys, that promotes the formation of red blood cells by the bone marrow.
• Glucose transporters (GLUT-1) are independent on insulin.
• There are four metabolic pathways that are essential for red cell function: Hexose monophosphate shunt pathway, Embden-Meyerhof glycolytic pathway, Luebering-Rapoport shunt, and methemoglobin reductase pathway.
• Energy in the form of ATP is supplied directly from glucose metabolism.
• The defect in Hereditary Stomatocytosis is a deficiency in the membrane protein, stomatin (Band 7).
• Glycophorin is a blood group antigen.
• Hereditary Elliptocytosis is autosomal dominant inherited.
• Band-3 protein, or anion channel, is mainly anion transporter protein of erythrocyte.
• In Hereditary Stomatocytosis, the intracellular sodium content increases, leading to increased water, causing the red cell to swell and appear as if the red cells have slits or bars in the center, as if the cell is “smiling.”
• Hereditary Stomatocytosis is a rare hemolytic disorder.
• The membrane defect in Hereditary Elliptocytosis is a disordered or deficient spectrin and proteins commonly associated with the alpha and beta spectrin regions.
• Splenectomy is contra-indicated in Hereditary Stomatocytosis due to the risk of trombotic complications.
• The Embden-Meyerhof pathway provides 90
• The defect in Hereditary Spherocytosis is a deficiency of the key membrane protein, spectrin, and to a lesser degree, a deficiency of membrane protein ankyrin and the minor membrane proteins Band 3 and Band 4.2.
• Stomatocytes may also be seen in individuals with Rh null disease.
• Band 1 and Band 2 are Spectrin.
• Glucose is transported through RBC membrane by facilitated diffusion through glucose transporters (GLUT-1).
• The RBC is highly dependent upon glucose as its energy source.
• Band 4.1 and Band 4.2 stabilize the binding between ankyrin and anion channel (Band-3).
• Erythrocytes have no nucleus and mitochondria.
• Spectrin molecules form a mesh-like pattern in the red cell membrane.
• Erythropoietin (EPO), also known as hemopoietin, is secreted by the kidney in response to cellular hypoxia; it stimulates red blood cell production (erythropoiesis) in the bone marrow.
• Hereditary Spherocytosis (HS) is characterized by the presence of spherocytes, which are the most common cause of inherited chronic hemolysis in Northern Europe.
• Hereditary Elliptocytosis (HE) is a highly variable red cell membrane disorder with many clinical subtypes.
• In Hereditary Spherocytosis, the sodium ion inflow to erythrocytes is accelerated by abnormal proteins, causing normal disc-shaped cells to become macro-micro spherocytic.
• Band-5 protein, Actin, is a component of the cytoskeleton.
• The Red Cell fragility test, also called erytrocytic osmotic resistance test, is a simple and easy method for diagnosing Hereditary Spherocytosis.
• Band-7 protein, Stomatin, is a component of the cytoskeleton.