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1.
2.
The kinetics of the hemolysis induced by filipin is of the damage type, indicating the formation of large nonselective perforations of erythrocyte membranes. The process is relatively independent of the ionic composition of the incubation medium, and the differences between the hemolysis induced by filipin in pig and human erythrocytes are not significant. In a sucrose medium, filipin-induced hemolysis is inhibited in humans, whereas it is stimulated in pig erythrocytes. It is suggested that low ionic strength is the reason for the different modifications of complexation of filipin in pig and human erythrocyte membranes in a sucrose medium. The kinetics of the hemolysis induced in pig erythrocytes by amphotericin B and nystatin is of the permeability type, indicating the formation of selective channels in erythrocyte membranes and colloid osmotic hemolysis. The rate of the hemolysis, which is high in a KCl medium, is decreased in all the other media tested (CaCl2, MgCl2, potassium phosphate buffer, K2SO4, sucrose), although there are no changes in the kinetics of hemolysis. The results are interpreted as the formation of highly selective channels at a low concentration of the antibiotics. At increasing concentrations, channels of decreasing selectivity occur. The resistances of pig erythrocytes to amphotericin B and nystatin are lower than those of human erythrocytes.  相似文献   

3.
Microcrystals of monosodium urate monohydrate(MSUM)induce cytolysis and hemolysis inerythrocytes.In this report,we studied the effect of vitamin E on MSUM-mediated hemolysis in humanerythrocytes.Vitamin E significantly inhibited hemolysis induced by MSUM.The hydroxyl group in thechromanol ring of vitamin E is dispensable for protecting erythrocytes against hemolysis induced by MSUM,indicating that the inhibitory effect of vitamin E is not due to its antioxidant properties.However,both thechromanol ring and the isoprenoid side chain are important for vitamin E to suppress MSUM-induced hemolysis.Our current study suggests that vitamin E inhibits hemolysis induced by MSUM as a membrane stabilizer.  相似文献   

4.
Washed erythrocytes from human, buffalo, sheep and goat preincubated with different concentrations of calcium chloride (16.7–1830 μM) showed significantly different rates of hemolysis (up to 62%) after addition of bilirubin (72 μM). Goat erythrocytes displayed marked resistance to hemolysis with only 11% hemolysis observed at the highest calcium concentration. Similar trend in hemolysis was also observed when the concentration of CaCl2 was fixed (330 μM) and bilirubin concentration varied (0–72 μM). (Ca2+–Mg2+)-ATPase levels were found significantly lower in goat and sheep erythrocyte membranes compared to human and buffalo erythrocyte membranes. This was correlated well with the observed hemolysis in various mammalian erythrocytes.  相似文献   

5.
Brown spiders have world‐wide distribution and are the cause of health problems known as loxoscelism. Necrotic cutaneous lesions surrounding the bites and less intense systemic signs like renal failure, DIC, and hemolysis were observed. We studied molecular mechanism by which recombinant toxin, biochemically characterized as phospholipase‐D , causes direct hemolysis (complement independent). Human erythrocytes treated with toxin showed direct hemolysis in a dose‐dependent and time‐dependent manner, as well as morphological changes in cell size and shape. Erythrocytes from human, rabbit, and sheep were more susceptible than those from horse. Hemolysis was not dependent on ABO group or Rhesus system. Confocal and FACS analyses using antibodies or GFP‐phospholipase‐D protein showed direct toxin binding to erythrocytes membrane. Moreover, toxin‐treated erythrocytes reacted with annexin‐V and showed alterations in their lipid raft profile. Divalent ion chelators significantly inhibited hemolysis evoked by phospholipase‐D , which has magnesium at the catalytic domain. Chelators were more effective than PMSF (serine‐protease inhibitor) that had no effect on hemolysis. By site‐directed mutation at catalytic domain (histidine 12 by alanine), hemolysis and morphologic changes of erythrocytes (but not the toxin's ability of membrane binding) were inhibited, supporting that catalytic activity is involved in hemolysis and cellular alterations but not toxin cell binding. The results provide evidence that L. intermedia venom phospholipase‐D triggers direct human blood cell hemolysis in a catalytic‐dependent manner. J. Cell. Biochem. 107: 655–666, 2009. © 2009 Wiley‐Liss, Inc.  相似文献   

6.
A very rapid hemolysis was found to be caused by active oxygen species produced by a hypoxanthine-xanthine oxidase system with very low concentrations of hypoxanthine. The addition of superoxide dismutase or catalase inhibited the hemolysis, indicating that O2- and H2O2 participate in this system. The extent of erythrocyte hemolysis was found to depend on the sex of the human donor. The change in phospholipid composition before and after hemolysis in human erythrocytes from donors of each sex was compared by thin layer chromatography. A significant decrease in phosphatidylethanolamine content and a concomitant increase in altered phospholipid fraction were observed in erythrocytes from male donors, suggesting that these erythrocytes were easily attacked by active oxygen species to produce modified phosphatidylethanolamine.  相似文献   

7.
Brown spider venom phospholipase-D belongs to a family of toxins characterized as potent bioactive agents. These toxins have been involved in numerous aspects of cell pathophysiology including inflammatory response, platelet aggregation, endothelial cell hyperactivation, renal disorders, and hemolysis. The molecular mechanism by which these toxins cause hemolysis is under investigation; literature data have suggested that enzyme catalysis is necessary for the biological activities triggered by the toxin. However, the way by which phospholipase-D activity is directly related with human hemolysis has not been determined. To evaluate how brown spider venom phospholipase-D activity causes hemolysis, we examined the impact of recombinant phospholipase-D on human red blood cells. Using six different purified recombinant phospholipase-D molecules obtained from a cDNA venom gland library, we demonstrated that there is a correlation of hemolytic effect and phospholipase-D activity. Studying recombinant phospholipase-D, a potent hemolytic and phospholipase-D recombinant toxin (LiRecDT1), we determined that the toxin degrades synthetic sphingomyelin (SM), lysophosphatidylcholine (LPC), and lyso-platelet-activating factor. Additionally, we determined that the toxin degrades phospholipids in a detergent extract of human erythrocytes, as well as phospholipids from ghosts of human red blood cells. The products of the degradation of synthetic SM and LPC following recombinant phospholipase-D treatments caused hemolysis of human erythrocytes. This hemolysis, dependent on products of metabolism of phospholipids, is also dependent on calcium ion concentration because the percentage of hemolysis increased with an increase in the dose of calcium in the medium. Recombinant phospholipase-D treatment of human erythrocytes stimulated an influx of calcium into the cells that was detected by a calcium-sensitive fluorescent probe (Fluo-4). This calcium influx was shown to be channel-mediated rather than leak-promoted because the influx was inhibited by L-type calcium channel inhibitors but not by a T-type calcium channel blocker, sodium channel inhibitor or a specific inhibitor of calcium activated potassium channels. Finally, this inhibition of hemolysis following recombinant phospholipase-D treatment occurred in a concentration-dependent manner in the presence of L-type calcium channel blockers such as nifedipine and verapamil. The data provided herein, suggest that the brown spider venom phospholipase-D-induced hemolysis of human erythrocytes is dependent on the metabolism of membrane phospholipids, such as SM and LPC, generating bioactive products that stimulate a calcium influx into red blood cells mediated by the L-type channel.  相似文献   

8.
Mechanical properties of erythrocyte membranes play an important role in red cell functions. Stability of human erythrocytes under deforming mechanical tensions which occur in the rapidly moving fluid is studied. The activation energy of the mechanical hemolysis determined by the temperature dependence of the hemolysis rate is 55 + 7 kJ/mol. The fragility of erythrocytes rises sharply as the salt concentrations increase. Glutaric dialdehyde forms a certain number of interprotein bonds which increase the fragility of erythrocytes. The mechanical stability of the erythrocyte membrane falls at high (0.5 M) ethanol concentrations. Blood plasma proteins, particularly human serum albumin, have a pronounced stabilizing effect. The hemolysis occurring during the rapid mixing is not probably associated with an osmotic mechanism since high sucrose concentrations do not prevent this process. The mechanical hemolysis depends both on the deforming tension arising in the membrane and on the state of the erythrocyte membrane.  相似文献   

9.
It is shown that non-covalent attachment of streptavidin, as well as of avidin, to biotinylated human erythrocytes induces homologous hemolysis by complement. Rabbit antiserum against human C3 is found to inhibit the lysis specifically as compared with non-immune rabbit serum. Efficiency of lysis inhibition is greater for avidin- and streptavidin-induced lysis of biotinylated human erythrocytes than for antibody-sensitized sheep erythrocytes. In contrast to positively charged avidin (pI 11), streptavidin is a neutral protein. Hence, hemolysis of streptavidin-carrying erythrocytes is inconsistent with the suggestion on the crucial role of avidin charge in lysis. Membrane alterations (cross-linking and clusterization of biotinylated components) induced by avidin (streptavidin) seem to be a more plausible explanation for the lysis.  相似文献   

10.
The interaction between thermostable direct hemolysin produced by Vibrio parahaemolyticus WP-1 and human erythrocytes was studied. The lysis of human erythrocytes by the hemolysin was dependent of temperature and no hemolysis occurred at low temperature (0-4 C), but the hemolysin was adsorbed on human erythrocytes even at low temperature. No hemolysis was observed when antihemolysin antiserum was mixed with the hemolysin and human erythrocytes at zero time. On the other hand, lysis of the cells by hemolysin was not completely inhibited when the antiserum was added during the lag time and the inhibitory effect decreased with delay in the time of addition of antiserum. The inhibitory effect of the antiserum decreased with increase in the incubation temperature, increase in the concentration of divalent cations, and decrease in pH. These results suggest that lysis of human erythrocytes by the hemolysin is at least a two-step process consisting of adsorption of the hemolysin to human erythrocytes and the step(s) following adsorption.  相似文献   

11.
The effects of the incubation temperature and bovine serum albumin on hemolysis induced by short-chain phosphatidylcholine were examined. The rate of hemolysis of human, monkey, rabbit, and rat erythrocytes by dilauroylglycerophosphocholine showed biphasic temperature-dependence: hemolysis was rapid at 5-10 degrees C and above 40 degrees C, but slow at around 25 degrees C. In contrast, the rate of lysis of cow, calf, sheep, pig, cat, and dog erythrocytes did not show biphasic temperature-dependence, but increased progressively with increase in the incubation temperature. Bovine serum albumin increased the hemolysis of human erythrocytes induced by dilauroylglycerophosphocholine or didecanoylglycerophosphocholine: it shortened the lag time of lysis and reduced the amount of phosphatidylcholine required for lysis. A shift-down of the incubation temperature from 40 to below 10 degrees C also shortened the lag time of lysis of human erythrocytes induced by dilauroylglycerophosphocholine and reduced the amount of phosphatidylcholine required for lysis.  相似文献   

12.
1. The hemolysis by serratamic acid, "N-(D-3-hydroxydecanoyl)-L-serine and N-(D-3-hydroxydodecanoyl)-L-serine", was investigated with human and animal erythrocytes using serratamic acid-containing liposomes. 2. The hemolytic activity was found to depend on the incubation temperature and the concentration of the liposomes. 3. The concentration of serratamic acid for 50% hemolysis was 0.17 mM at 37 degrees C for 0.2% human erythrocyte suspension in the liposomes which composed of phosphatidylserine, cholesteryl nervonate and serratamic acid (1:0.50:0.37 by mol). 4. The hemolysis was shown specifically in human, horse and rabbit erythrocytes containing phosphatidylcholine, but not in sheep or bovine erythrocytes lacking phosphatidylcholine. 5. The hemolytic activity was strongly inhibited by the exogenous addition of phosphatidylcholine. It was suggested that the hemolysis by serratamic acid-containing liposomes was specific for phosphatidylcholine-containing erythrocyte membranes.  相似文献   

13.
Human erythrocytes suspended in an isotonic Na-phosphate buffer, pH 7.4 (hematocrit 2%) were exposed under air to gamma radiation at a dose rates of 2.2 kGy.h-1 and 4.2 kGy.h-1. The dose-response curves for hemolysis of erythrocytes indicated that the process of hemolysis is inversely related to the dose-rate. At both dose-rates we observed a reduced level of hemolysis, when erythrocytes were irradiated with a split dose (0.4 kGy + 2.3 kGy with an interval time between the subsequent exposures from 1 to 4 h) in comparison with the same single dose (2.7 kGy). The maximal effect of fractionation was observed when the interfraction time was equal to 3.5 h. The influence of the interfraction temperature on this effect was observed. The results obtained indicate that enucleated human erythrocytes under suitable radiation conditions are capable of repairing radiation damage which leads to hemolysis.  相似文献   

14.
When erythrocytes from different mammalian species are compared, the hemolysis rate in 0.3 m glycerol is seen to be directly related to the percentage of lecithin in the erythrocyte phospholipid. Since this percentage is higher in erythrocytes from human adults than in those from infants, the hemolysis times in 0.3 m glycerol were compared. As expected, hemolysis was more rapid in the adult cell, which is therefore more permeable to glycerol under these conditions. The permeability to glycerol of a film of erythrocyte lipids in vitro was next examined in a model system containing the two phases water and butanol. Lipid introduced into the bulk butanol appears as a film at the interface. When equal amounts of total lipid extracted from adult and fetal erythrocytes were introduced into the butanol phase of two such chambers, the initial flux of glycerol-(14)C across the lipid boundary was greater in the cell containing lipid from adult erythrocytes than in the cell containing fetal erythrocyte lipid. This difference corresponds qualitatively to the difference in hemolysis time measured in the intact erythrocytes.  相似文献   

15.
Microcrystals of hydroxyapatite cause severe membrane damage in human erythrocytes, as is evident from the strong hemolysis that is caused by these crystals. Hemolysis by hydroxyapatite crystals is time and concentration dependent, and is preceded by aggregation of erythrocytes. Polyvinylpyridine-N-oxide, a strong hydrogen acceptor, has no inhibiting effect on hydroxyapatite-induced hemolysis. This suggest that the mechanism of action of these crystals is different from that of urate crystals and silica particles, where hydrogen bonding interaction is supposed to be important. Negatively charged macromolecules, such as dextran sulfate, heparin, and polyglutamic acid, inhibit hydroxyapatite crystal-induced hemolysis, suggesting that positive charges, probably located on the crystals, play an important role in the membrane-damaging effect of these crystals. The structures with which these positive charges interact remain to be determined because removal of negative charges from the erythrocytes by treatment with neuraminidase does not affect crystal-induced hemolysis.  相似文献   

16.
Staphylococcal γ-hemolysin consists of two protein components, F (or HγI) and HγII. To elucidate the mode of action of γ-hemolysin, we studied the binding order of F and HγII to human erythrocytes and the cell-bound state of the two components. The binding of F to human erythrocytes preceded the binding of HγII to the cells, and thereafter hemolysis occurred. Western immunoblot analysis of the cell-bound γ-hemolysin indicated that F and HγII components form high-molecular-mass (150–250 kDa) complexes on the erythrocytes. The toxin complexes were recovered in a Triton X-100-insoluble fraction of the erythrocytes, which contains cytoskeleton proteins. Neither the formation of the toxin complex(es) nor hemolysis occurred when the erythrocytes were treated with proteinase K. Abortion of the complex formation on the proteinase K-treated erythrocytes may be due to the failure of the binding of HγII to the cells, because F bound to the proteinase K-treated erythrocytes to the same extent as to the non-treated erythrocytes.  相似文献   

17.
Vitamin E involves a group of tocopherols and tocotrienols, in which α-tocopherol with the highest biological activity plays a more efficient role in advanced lesions with aged oxidized tissues. However, the results of the present study reveal that a large amount of endogenous α-tocopherol in human low-density lipoprotein (LDL) in the absence of any other antioxidants may initiate additional free radical propagation under low concentration of free radical initiator (i.e., 2,2′-azobis(2-amidinopropane hydrochloride) [AAPH], a water-soluble free radical source) to peroxide polyunsaturated fatty acids in LDL in the manner of α-tocopherol-mediated peroxidation (TMP). Whether the addition of high concentration of exogenous α-tocopherol to human erythrocytes under low concentration of AAPH can also drive TMP is the concern in this research work. Moreover, the hemolysis extent of human erythrocytes peroxidized by AAPH is followed easily by the determination of the hemoglobin outside the erythrocytes. A series of observations on various concentrations of AAPH-induced hemolysis in the presence of various concentrations of exogenous α-tocopherol demonstrates that the high concentration of exogenous α-tocopherol, coupled with low concentration of AAPH, can initiate TMP in the free-radical-induced peroxidation of human erythrocytes system as well. This result provides direct evidence to support TMP theory and expands its application into in vitro erythrocytes system.  相似文献   

18.
《Insect Biochemistry》1991,21(2):113-120
Posterior-midgut homogenate from female stable flies prepared at 12 h after feeding hemolyzed erythrocytes from 6 different mammalian species more readily than homogenate prepared at 22 h. A significant correlation was obtained between the per cent sphingomyelin content of the erythrocyte membrane and the time required for lysis by the 12 h homogenate. Erythrocytes with low sphingomyelin content were more sensitive to lysis than cells with high sphingomyelin. No such correlation exists for hemolysis by 22 h homogenate. Mean corpuscular volume and osmotic fragilities of erythrocytes were not related to hemolysis either by 12 or 22 h homogenate. Determination of phospholipase C and sphingomyelinase activities showed that the hydrolysis rate of phospholipase C in homogenates prepared at 12–14 h was almost twice as much as sphingomyelinase activity. Whereas hydrolysis rates in 22–24 h homogenate were not different and markedly reduced compared to the 12–14 h homogenate. The times required for erythrocyte hemolysis related to the phospholipase C and sphingomyelinase activity profiles suggests that these enzyme activities participate in the in vitro hemolysis of red blood cells. Bovine and human erythrocytes change their biconcave contour into a spiculated spherical shape when they are exposed to midgut homogenate. This shape change is interpreted as a detergent induced modification of the red cell membrane which renders the erythrocytes more vulnerable to hemolysis.  相似文献   

19.
Adverse drug reactions (ADR), especially intravenous hemolysis, have largely limited the application of puerarin injections in clinics. This study investigated the underlying mechanisms of puerarin-induced hemolysis. Our results show that puerarin induced concentration-dependent and time-dependent hemolysis when human erythrocytes were incubated in saline solution with more than 2 mM puerarin for over 2 h. However, incubation in PBS or addition of 1 mM of lidocaine to the saline solution completely abolished the hemolysis. Providing materials that could start ATP synthesis did not reverse the hemolysis, and puerarin did not affect Na+–K+–ATPase activity. In addition, puerarin (0.1–2 mM) did not cause calcium influx or exhibited pro-oxidant activity in erythrocytes. Puerarin exhibited different influences on the membrane microviscosity of erythrocytes in saline and PBS. Moreover, 1 mM lidocaine inhibited 8 mM puerarin-induced reduction of membrane microviscosity in saline solution. SDS–PAGE analysis of membrane proteins revealed that 2 mM puerarin treatment induced the appearance of several new protein bands but attenuated the expression of protein bands 2.1, 3, 4.1, 4.2 and 5. These results suggest that high concentrations of puerarin-induced hemolysis were associated with the changes of membrane lipids and of the composition of erythrocytes membrane proteins but not with ATP depletion, pro-oxidation and calcium influx. These changes could be related to the intercalation of amphiphilic puerarin at high concentration into the erythrocyte membrane in certain media, resulting in membrane disorganization and, eventually, cytolysis. Hence, in clinics, determining the optimal dose of puerarin is critical to avoid overdosing and ADR.  相似文献   

20.
Both hypochlorite and ionizing radiation induce oxidation processes of biomolecules. The effects are dependent to a large degree on the dose of the oxidizing agent. Previously we observed that split doses of gamma radiation caused lower hemolysis than the same but single doses. The critical factors influencing the occurrence of this effect were: the value of the first dose and the time between the doses. In this work we examined the effect of gamma radiation (40-400 Gy) on hemolysis of human erythrocytes induced by hypochlorite. Erythrocytes in PBS, hematocrit 2 %, were irradiated with doses of 40, 200 or 400 Gy. The dose-rate was 23.8 Gy/min. Cell suspensions were stirred during irradiation. After irradiation the erythrocytes were incubated for 1, 3 or 4 hours at room temperature and then hypochlorite was added to a 250 microM concentration. Control samples were erythrocytes treated only with NaOCl. The level of hemolysis was determined after NaOCl addition. Hemolysis of erythrocytes preirradiated with the dose of 400 Gy was lower than hemolysis of erythrocytes treated only with NaOCl. The effect was dependent on the time between the end of irradiation and the addition of NaOCl. In contrast, slightly higher hemolysis was observed for erythrocytes preirradiated with lower (40 or 200 Gy) doses of radiation. The observed effect is similar to that obtained for radiation-induced hemolysis. It suggests that ionizing radiation may induce structural and/or functional changes in erythrocytes, which make the cell more resistant to further oxidative damage.  相似文献   

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