pH EFFECT ON HUMAN ERYTHROCYTE SHAPE
The effect of pH on shape of intact erythrocyte was studied by suspending erythrocyte in phosphate buffer saline of pH outside the range 8.0 to 4.0. These were found to induced instantly two typical types of shape changes of human erythrocyte when added into the erythrocyte suspension. Generally, as the pH of the suspending media decreased toward acidity (pH 3.0 – 1.0) cup shape calls (invagmation) were formed. Subsequently, this was accomplished by cell lyrics. On the other hand, increasing pH of the suspending media toward – alkalinity (pH 8.0 – 12.0) induced crenation (externalization) on the erythrocyte membrane. Accompanying this type of shape change were a progressive increased in cell lyrics which began as pH of the media increased to pH 11.0. Ghost cells also formed at this pH
TABLE OF CONTENTS
Title Page i
Table of Contents vi
GENERAL INTRODUCTION AND LITERATURE REVIEW
1.2 Red Cell Membrane
1.3 Analysis of Membrane Constitution
1.4 Red Cell Shape Deformability
1.5 Scope of the Project
2.0 Materials and Method
3.1 Analysis of Shape of erythrocyte induced by change in pH Value
GENERAL INTRODUCTION AND LITERATURE REVIEW
The normal mature erythrocyte are biconcave disks having a means diameter of approximately 8 microns and a thickness at the point of 2 microns and in the center of 1 micron or less (Guyton 1981).
The red cells was thought to be composed of two main parts: a retaining membrane and a highly concentrated solution of hemoglobin (Cooper et al 1950). But with further analytical studies, it was suggested that the red cells is compose of 7% water, 28% hemoglobin, 70% membrane lipid such as cholesterol, lecithin, phospholipid (Moskowitz and Calvin 1982, Perutz et al 1960) and 3% sugars, salt, enzyme protein and membrane protein (Budewig 1960).
1.2 RED CELL MEMBRANE
Shape controlling factors have been placed both within the interior of the cell (Shrivastastar and Burton 1969) and in the membrane but the membrane was generally considered to be responsible for the biconcave shape (Weed et al 1963). Actually, the red blood cell is a bag that can be deformed into almost any shape (Guyton 1981). Furthermore, because the normal cell has a great excess of cell membrane for the quantity of material inside, deformation does not stretch the membrane and consequently does not rupture the cell as would be the case with many other cells (Guyton 1981).
1.3 ANALYSIS OF MEMBRANE CONSTITUTION
1.3.1 RED CELL MEMBRANE LIPID
The total lipid that can be extended from red cells (approximately 1.0ml of packed cells) is 5mg. the extracted lipid are subdivided into three main classes, phospholipids 60% neutral 30% and glycolipids 10% (Watkins 1974).
The phospholipids comprise two main classes, glycerophosphate and sphingomyelin. Reed (1968) demonstrated that 60% of lectithin and 30% of sphingomyelin were exchange between the plasma and the human red cell membrane over five days. Lysolecithin (the monoacyl form of lecithin) which can be formed in the plasma through the esterification of free cholesterol by the action of the enzyme lecithin – cholesterol acyl-transferase, a fatty acid being transferred, from lecithin to cholesterol, has been shown to rapidly equilibrate with the membrane (Waku and lands. 1968, Shohet and Nathan, 1970), the lysolecithin undergoing acylation by the action of acyl-transferase to form lecithin. Shohet in 1971 demonstrated the transfer off labeled fatty acids between phospholipids notably from lecithin to phosphatidyl ethabolamine. There is uncertainty as to whether the interconversion of labeled fatty acids between the different classes of diacylphosphoglycerides takes place as a result of direct transacylation or through the combined action of phosphatases and an acyltransferase which catalyzes the phosphate formed through the action of the phospholipase (Shohet 1972).
A defect in transacylation has been postulated to account for the increased phosphatidyl choline and diminished phosphatidyl ethanolamine observed in the red cell membrane of the members of a family with nonspharocytic heamolytic anaemia (Shohet et al 1971). More recently Wiley and co-workers (1973) have shown that a similar disorder in the relative proportion of these two phospholipids may be found in patients with hereditary stomatocytosis.
KEYWORDS;effect of ph on red blood cells, what is the ph of a human blood cell