Correlations of Na+-Li+Exchange Activity With Na+and Li+Binding and Phospholipid Composition in Erythrocyte Membranes of White Hypertensive and Normotensive Individuals

Hypertension ◽  
1996 ◽  
Vol 27 (3) ◽  
pp. 456-464 ◽  
Author(s):  
Yuling Chi ◽  
Duarte Mota de Freitas ◽  
Mary Sikora ◽  
Vinod K. Bansal
Author(s):  
O Chabanenko ◽  
◽  
N Yershova ◽  
N Orlova ◽  
N Shpakova ◽  
...  

The effect of cationic trifluoperazine (TFP) and nonionic decyl-β,D-glucopyranoside (DGP) on the sensitivity of human, rabbit and rat erythrocytes to the action of posthypertonic shock (PHS) at 0 °C was studied in this research. Trifluoperazine shows a high antihemolytic activity under conditions of PHS of human and animal erythrocytes at slight differences of values of effective concentrations. The value of antihemolytic activity of TFP for human and rabbit erythrocytes is ~ 60 %, and for rat cells the efficiency of this compound is approximately 1.4 times higher. The values of antihemolytic activity of DGP under PHS conditions of human and rat erythrocytes are comparable and amounts to 62 and 66 %, respectively. Significant differen­ces of this parameter (72 %) were found for rabbit cells compared with human erythrocytes. It was found that the size of plateau (the range of concentrations of amphiphilic compounds within the minimum level of erythrocyte hemolysis was observed) cationic TFP and nonionic DGP are significantly different. Thus, TFP has a narrow plateau (100–200 μmol/L), while DGP has a rather wide one (400–1600 μmol/L). In addition, a shift of the plateau concentrations of DGP to the region of higher values compared with TFP is observed, which is probably due to the fact that the value of the critical micelle concentration DGP is higher than TFP. Moreover, a shift of plateau concentrations of DGP to the region of higher values compared with TFP is observed, that is probably due to the fact that the value of the critical micelle concentration DGP is higher than TFP one. It was established that under PHS conditions of human erythrocyte, both compounds (TFP and DGP) show a commensurate antihemolytic activity. At the same time, for rabbit cells, DGP is more effective compared with TFP, and for rat erythrocytes, on the contrary, the efficiency of TFP is higher than DGP. This may be due to differences in the phospholipid composition of mammalian erythrocyte membranes. The results suggest that under PHS conditions the efficacy of membrane-tropic compounds is most likely due to their ability to incorporate into membrane to the defect formation areas, and thus significantly increase the critical hemolytic volume of cells, as a result, prevent their destruction.


Author(s):  
Kamen Koumanov ◽  
Atanas Boyanov ◽  
Tania Neicheva ◽  
Tania Markovska ◽  
Albena Momchilova ◽  
...  

2011 ◽  
Vol 35 (8) ◽  
pp. 521-530 ◽  
Author(s):  
Alida Maria Ferlazzo ◽  
Giuseppe Bruschetta ◽  
Patrizia Di Pietro ◽  
Pietro Medica ◽  
Anna Notti ◽  
...  

1991 ◽  
Vol 274 (1) ◽  
pp. 121-132 ◽  
Author(s):  
L L Hsiao ◽  
R J Howard ◽  
M Aikawa ◽  
T F Taraschi

The phospholipid and fatty acid compositions of the host infected erythrocyte plasma membrane (IEPM) have been determined for erythrocytes infected with the human malaria parasite Plasmodium falciparum. IEPM were prepared by selective lysis of the host erythrocyte (but not of the parasite membranes) with 0.1% saponin, followed by differential centrifugation. The purity of the IEPM was determined by measuring the membrane-specific enzyme markers acetylcholinesterase, glutamate dehydrogenase and lactate dehydrogenase, and by immunoelectron microscopy using monoclonal antibodies specific for human erythrocyte glycophorin A (4E7) and for a 195 kDa parasite membrane glycoprotein (Pf6 3B10.1). Both approaches demonstrated that the host erythrocyte plasma membrane preparation was free from contamination by parasite membranes. During intra-erythrocytic development of the parasite, the phospholipid composition of the erythrocyte membrane was strikingly altered. IEPM contained more phosphatidylcholine (38.7% versus 31.7%) and phosphatidylinositol (2.1% versus 0.8%) and less sphingomyelin (14.6% versus 28.0%) than normal uninfected erythrocytes. Similar alterations in phospholipid composition were determined for erythrocyte membranes of parasitized cells isolated by an alternative method utilizing polycationic polyacrylamide microbeads (Affigel 731). The total fatty acid compositions of the major phospholipids in IEPM were determined by g.l.c. The percentage of polyunsaturated fatty acids in normal erythrocyte phospholipids (39.4%) was much higher than in phospholipids from purified parasites (23.3%) or IEPM (24.0%). The unsaturation index of phospholipids in IEPM was considerably lower than in uninfected erythrocytes (107.5 versus 161.0) and was very similar to that in purified parasites (107.5 versus 98.5). Large increases in palmitic acid (C16:0) (from 21.88% to 31.21%) and in oleic acid (C18:1) (from 14.64% to 24.60%), and major decreases in arachidonic acid (C20:4) (from 17.36% to 7.85%) and in docosahexaenoic acid (C22:6) (from 4.34% to 1.8%) occurred as a result of infection. The fatty acid profiles of individual phospholipid classes from IEPM resembled in many instances the fatty acid profiles of parasite phospholipids rather than those of uninfected erythrocytes. Analysis of IEPM from P. falciparum-infected erythrocytes (trophozoite stage) revealed that, during intra-erythrocytic maturation of the parasite, the host erythrocyte phospholipid composition was markedly refashioned. These alterations were not dependent on the method used to isolate the IEPM, with similar results obtained using either a saponin-lysis method or binding to Affigel beads. Since mature erythrocytes have negligible lipid synthesis and metabolism, these alterations must occur as a result of parasite-directed metabolism of erythrocyte lipids and/or trafficking of lipids between the parasite and erythrocyte membranes.


Blood ◽  
1993 ◽  
Vol 81 (4) ◽  
pp. 1051-1057 ◽  
Author(s):  
FA Kuypers ◽  
BH Lubin ◽  
M Yee ◽  
P Agre ◽  
PF Devaux ◽  
...  

Abstract In the human erythrocyte membrane phosphatidylcholine and sphingomyelin reside mainly in the outer leaflet, whereas the aminophospholipids, phosphatidylethanolamine and phosphatidylserine, are mainly found in the inner leaflet. Maintenance of phospholipid asymmetry has been assumed to involve interactions between the aminophospholipids and the membrane skeleton, in particular spectrin. To investigate whether spectrin contributes to maintaining the phospholipid transbilayer distribution and kinetics of redistribution, we studied erythrocytes from hereditary spherocytosis patients whose spectrin levels ranged from 34% to 82% of normal. The phospholipid composition and the accessibility of membrane phospholipids to hydrolysis by phospholipases were in the normal range. Spin-labeled phosphatidylserine and phosphatidylethanolamine analogues that had been introduced into the outer leaflet were rapidly transported at 37 degrees C to the inner leaflet, whereas the redistribution of spin-labeled phosphatidylcholine was slower. The kinetics of transbilayer movement of these spin-labeled phospholipid in all samples was in the normal range and was not affected by the level of spectrin. Although these erythrocyte membranes contained as little as 34% of the normal level of spectrin and were characterized by several physical abnormalities, the composition, distribution, and transbilayer kinetics of the phospholipids were found to be normal. We therefore conclude that spectrin plays, at best, only a minor role in maintaining the distribution of erythrocyte membrane phospholipid.


Blood ◽  
1993 ◽  
Vol 81 (4) ◽  
pp. 1051-1057 ◽  
Author(s):  
FA Kuypers ◽  
BH Lubin ◽  
M Yee ◽  
P Agre ◽  
PF Devaux ◽  
...  

In the human erythrocyte membrane phosphatidylcholine and sphingomyelin reside mainly in the outer leaflet, whereas the aminophospholipids, phosphatidylethanolamine and phosphatidylserine, are mainly found in the inner leaflet. Maintenance of phospholipid asymmetry has been assumed to involve interactions between the aminophospholipids and the membrane skeleton, in particular spectrin. To investigate whether spectrin contributes to maintaining the phospholipid transbilayer distribution and kinetics of redistribution, we studied erythrocytes from hereditary spherocytosis patients whose spectrin levels ranged from 34% to 82% of normal. The phospholipid composition and the accessibility of membrane phospholipids to hydrolysis by phospholipases were in the normal range. Spin-labeled phosphatidylserine and phosphatidylethanolamine analogues that had been introduced into the outer leaflet were rapidly transported at 37 degrees C to the inner leaflet, whereas the redistribution of spin-labeled phosphatidylcholine was slower. The kinetics of transbilayer movement of these spin-labeled phospholipid in all samples was in the normal range and was not affected by the level of spectrin. Although these erythrocyte membranes contained as little as 34% of the normal level of spectrin and were characterized by several physical abnormalities, the composition, distribution, and transbilayer kinetics of the phospholipids were found to be normal. We therefore conclude that spectrin plays, at best, only a minor role in maintaining the distribution of erythrocyte membrane phospholipid.


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