Morphological basis of the aging erythrocytes deformability

Abstract

Red blood cells are flexible and oval biconcave disks, they lack a cell nucleus and their disk diameter is 7–10 μm. Approximately 2.4 million new erythrocytes are produced per second and circulate for about 100–120 days in the body. Red blood cells are cells present in blood in order to transport oxygen, the aging red blood cell undergoes changes making it susceptible to selective recognition by macrophages and subsequent phagocytosis. The cytoplasm of erythrocytes is rich in hemoglobin, an iron-containing biomolecule that can bind oxygen and is responsible for the red colour of the cells. Immature red blood cells are lacking the red hemoglobin pigment so these cells are often shades of grayish blue, only mature cells are red.A glycophorin is a sialoglycoprotein of the membrane of a red blood cell, that contains N-acetylneuraminic acid. Ions such as Na+ and Ca2+ can diffuse rapidly through it and can be for 60% it`s negative charge of the plasma membrane. Typical human red blood cell has a diameter of approximately 6.2–8.2 μm, a thickness - 2 μm, circumference – 76-110 μm, speed no more than 2 cm/ sec that is enough to transport oxygen from hemoglobin toward myoglobin. Listed features are changed depending on the lifespan of red blood cells: 1. Decreases the percentage of hemoglobin content, within the part of it is broken down. 2. Changes occurs in the activities electronic change in oxidation and restoration of Fe. 3. As erythrocyte ages, it undergoes changes in its plasma membrane, in particular sialic acid activity. 4. Erythrocyte membrane becomes inflexible, less elastic and rough. 5. Worn-out red blood cells (100-120 day) have a limited functional significance. As a result of this research, both functional and physical indicators are strictly differentiated regarding to human age: 1. The length of erythrocyte life in the elderly (70-75) is twice longer than in younger people (25-30). 2. Red blood cells are remarkably deformable in younger than in elderly people. 3. Because of decreased deformability of the red blood cell, they have trouble to squeeze through capillaries which is the reason of hemodynamics local violations.