Hypotonic hemolysis

Seeman, P. (1967) Transient holes in the erythrocyte membrane during hypotonic hemolysis and stable holes in the membrane after lysis by saponin and lysoleci-thin. J. Cell Biol. 32, 55-70. 

Inhibited hypotonic hemolysis of human erythrocytes by membrane incorporation 365... 

Induced invagination and increased resistance of human erythrocytes to hypotonic hemolysis 365... 

Holmberg B, Jakobson I, Malmfors T. 1974. The effect of organic solvents on erythrocytes during hypotonic hemolysis. Environ Res 7 193-205. 

Furanocoumarin 8-methoxypsoralen (8-MOP) (1-100 pg/ml) in the dark showed a protective affect against hypotonic hemolysis of the erythrocyte membrane. However, the effect against heat-induced hemolysis was dependent on the concentration of 8-MOP lower concentrations of 8-MOP showed an inhibiting effect, whereas higher concentrations caused acceleration of hemolysis. The erythrocytes reacted with 8-MOP in the dark were shrunk and had altered shapes. It can be deduced that modification of erythrocyte membrane by 8-MOP is via the reaction with membrane lipids and proteins [295]. From these results, it could be concluded that the effect on the cell membrane by coumarins could have an important role in their bioactivity. 

Stabilization of lysosomal membranes has been implicated as an Important mechanism of steroidal and non-steroidal anti-inflammatory drugs. Phenylbutazone, flufenamic acid and acetylsallcylic acid Inhibit the release of acid phosphatase and 8-glucuronidase from Isolated rat liver lysosomes incubated in buffered sucrose (pH 7. ). In acidic sucrose (pH 5), acetyl-salicylic acid enhances lysosomal enzyme release. Acetylsallcylic acid indomethacin and phenylbutazone do not stabilize rabbit liver lysosomes In vitro stabilization of isolated erythrocytes against hypotonic hemolysis and heat-induced hemolysis " by non-steroidal anti-inflammatoiy agents has been employed as a rapid, accurate screening model. The stabilizing potency apparently correlates with the clinical activities of standard anti-rheumatic drugs. 

Antihemolytic - in vitro (human adult, membrane-erythrocyte) at 10.0 pM, vs. hypotonic hemolysis. Antiinflammatory - in vivo (IP, rat) dose not stated, (IP, mouse), route and dose not given, and (External, mouse) at 1.0 mg/ear, induced inflammation by arachidonic add and tetradecanoyl-phorbol-13-acetate. 

It is important that injectable solutions that are to be given intravenously are isotonic, or nearly so. Because of osmotic pressure changes and the resultant exchange of ionic species across red blood cell membranes, nonisotonic solutions, particularly if given in quantities larger than 100 mL, can cause hemolysis or cre-nation of red blood cells (owing to hypotonic or hypertonic solutions, respectively). Dextrose, sodium chloride, or potassium chloride is commonly used to achieve isotonicity in a parenteral formula. 

Embolism is another possible complication of the IV route. Particulate matter may be introduced if a drug intended for intravenous use precipitates for some reason, or if a particular suspension intended for IM or SC use is inadvertently given into a vein. Hemolysis or agglutination of erythrocytes may be caused by injection of hypotonic/hypertonic solutions, or by more specific mechanisms (Gray, 1978). 

Hypotonic solutions will cause a net flow of solvent into the cells to equalize the osmotic pressure. The cells will burst and die (hemolysis). Hypertonic solutions will cause a net flow of solvent out of the cells to equalize the osmotic pressure. The cells will shrink and die. 

Living cells, among them the red blood cells, are surrounded by semipermeable membranes. The osmolarity of most cells is 0.30 osmol. For example, a 0.89% w/v NaCl solution, normally referred to as physiological saline solution, has an osmolarity of 0.30. Thus when a cell is put in physiological saline solution, the osmolarity on both sides of the membrane is the same and therefore no osmotic pressure is generated across the membrane. Such a solution is called isotonic. On the other hand, if a cell is put in water (pure solvent) or in a solution which has lower osmolarity than the cell, there will be a net flow of water into the cell driven by the osmotic pressure. Such a solution is called hypotonic. A cell placed in a hypotonic solution will swell and eventually may burst. If that happens to a red blood cell, the process is called hemolysis. In contrast, a solution with higher osmolarity than the cell is called a hypertonic solution. A cell suspended in a hypertonic solution will shrivel there is a net flow of water from the cell into the surroundings. When that happens to a red blood cell, the process is called crenation. 

Mammalian red blood cells have a biconcave (doughnut-like) shape. If red blood cells are placed in a 0.3 M NaCl solution, there is little net osmotic movement of water, the size and shape of the cells stay the same the NaCl solution is isotonic to the cell. If red blood cells are placed in a solution with a lower solute concentration than is found in the cells, water moves into the cells by osmosis, causing the cells to swell such a solution is hypotonic to the cells. When red blood cells are placed in pure water, water rapidly enters the cells by osmosis and causes the cells to burst, a phenomenon known as hemolysis. If the red blood cells are placed in a solution with a higher solute concentration, water moves out of the cell by osmosis, the cell becomes smaller and crenated in shape such a solution is hypertonic to the cells. 

These observations have several important practical implications. First, hospitals must store red blood cells in a plasma solution which has the correct proportions of salts and proteins. The plasma solution is made to be slightly hypertonic to the red cells so that the integrity of the cells is preserved and hemolysis is prevented. Second, when doctors inject a drug intravenously into a patient, the drug is suspended in a saline solution which is slightly hypertonic to red blood cells. Intravenous injection of a drug in pure water will cause some of the patient s red blood cells to hemolyze because water is hypotonic to the red blood cells. 

It has been also observed that hypertonic and hypotonic salt solutions tend to irritate sensitive tissue and cause pain when applied to mucous membranes of the eye, ear, and nose, etc., whereas isotonic solution causes no tissue irritation when it comes in contact with the tissue. Obviously, the tonicity of formulations that come in to direct contact with blood, muscle, eye, nose, and delicate tissues is critical. Therefore, the issue of tonicity is important in small- and large-volume injectables, ophthalmic products, and products intended for tissue irrigation. The degree of tissue irritation or hemolysis or crenation observed depends on the degree of deviation from isotonicity, the volume injected, the speed of injection, the concentration of the solutes in the injection, and the nature of the membrane. The parenteral and ophthalmic formulations are therefore adjusted to isotonicity if possible. 

Erythrocytes contain 32 to 55% hemoglobin, about 60% water, and the rest as siroma. Stroma can be obtained, after hemolysis of the corpuscles by dilution, through the process of centrifuging and consists of lecithin, cholesterol, inorganic salts, and a protein, siromalin. Hemoly.sis of the corpuscles. or "laking" as i( is sometimes culled, may be brought about by hypotonic solution, by fat solvents, by bile... 

The osmotic pressure phenomenon manifests itself in many interesting applications. To study the contents of red blood cells, which are protected from the external environment by a semipermeable membrane, biochemists use a technique called hemolysis. The red blood cells are placed in a hypotonic solution. Because the hypotonic solution is less concentrated than the interior of the cell, water moves into the cells, as shown in Figure 12.14(b). The cells swell and eventually burst, releasing hemoglobin and other molecules. 

Several physiologic roles for CS have been postulated. First, it has been suggested that the presence of CS in erythrocytes (about 700 fig of CS are present in 100 ml erythrocytes [125]) stabilizes the erythrocyte membrane [130]. Thus, CS was found to reduce hemolysis up to 56% in hypotonic solutions, whereas several other steroid sulfates and cholesterol conjugates were devoid of antihemolytic activity [125]. Furthermore, the presence of CS had a critical influence on the disc shape of erythrocytes in hypotonic solution without CS, erythrocytes tended to become spherical and extend spicules [131]. A second postulated role of CS relates to spermatozoa. It has been suggested that CS stabilizes the membranes of these cells and that it may provide a structural trigger for capacitation [132,133]. Thus, CS is present in spermatozoa (15 fig/lO cells) as well as in seminal plasma, and appears to be concentrated in the acrosomal region [132]. On the other hand, sterol sulfatase activity is present in the human female reproductive tract [133]. There is no direct evidence, however, that CS contributes to the sperm membrane modification reactions that occur in association with fertilization. 

In biological systems, if the concentration of the fluid surrounding red blood cells is higher than that inside the cell (a hypertonic solution), water flows from the cell, causing it to collapse (crenation). Too low a concentration of this fluid relative to the solution within the cell (a hypotonic solution) will cause cell rupture (hemolysis). 

In the HER-100 (Omron Tateisi, Japan) an asymmetric cellulose acetate membrane is used, bearing LOD covalently bound by y-aminopropyltriethoxysilane and cross-linked with glutaraldehyde [371]. The membrane is highly selective for hydrogen peroxide. The analyzer is suitable for lactate assay in human serum. Pol)rurethane-immobilized LOD is used for whole blood lactate determination in both the Glukometer and in the ECA 20 (ESAT 6660) [372]. Dilution of the samples with a hypotonic buffer provides for both complete inhibition of glycolysis and immediate hemolysis. As shown by the correlation equations, the method appears to be fairly reliable ... 

Soiutions that have identical osmotic pressures are said to be isotonic solutions. Fluids administered intravenously must be isotonic with body fluids. For example, if red blood cells are bathed in a hypertonic solution, which is a solution having an osmotic pressure higher than that of the cell fluids, the cells will shrivel because of a net transfer of water out of the cells. This phenomenon is called crenation. The opposite phenomenon, called hemolysis, occurs when cells are bathed in a hypotonic solution, a solution with an osmotic pressure lower than that of the cell fluids. In this case, the cells rupture because of the flow of water into the cells. 

Osmosis plays an important role in living systems. The membranes of red blood cells, for example, are semipermeable. Placing a red blood cell in a solution that is hypertonic relative to the intracellular solution (the solution inside the cells) causes water to move out of the cell ( FIGURE 13.26). This causes the cell to shrivel, a process called crenation. Placing the cell in a solution that is hypotonic relative to the intracellular fluid causes water to move into the cell. This may cause the cell to rupture, a process called hemolysis. People who need body fluids or nutrients replaced but cannot be fed orally are given solutions by intravenous (IV) infusion, which feeds nutrients directly into the veins. To prevent crenation or hemolysis of red blood cells, the IV solutions must be isotonic with the intracellular fluids of the blood cells. 

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