Dantrolene sodium in vitro inhibited the ATP-dependent efflux of calcium from human Fed cells, the Ca++-ATPase activity of red blood cell membrane fragments (RBCMF) and passive calcium binding to RBCMF. These effects were obtained With concentrations of dantrolene sodium between 2.5 and 20 uM. However the passive influx of Ca++ was measured at 37 degrees C in cells pretreated to abolish Ca++ pumping and was not influenced by dantrolene sodium. From these results, it was concluded that dantrolene sodium inhibits an active Ca++ extrusion across the red cell membrane by inhibiting Ca++-ATPase activity which is intimately involved with the Ca++ transport mechanism in the red cell membrane.
Calcium/metabolism* ; Dantrolene/pharmacology* ; Erythrocyte Membrane/drug effects* ; Erythrocyte Membrane/metabolism ; Human ; Ion Channels/drug effects* ; Ion Channels/metabolism

AIM AND METHODSThe purpose of this investigation was to determine the changes of erythrocyte deformability, band-3 protein and actin in the definite volume of erythrocyte membrane after high intensity running training and recovery in rats.

RESULTSLong-term training could significantly improve erythrocyte deformability and the quantity of membrane proteins. Erythrocyte deformability, band-3 protein and actin decreased transitorily at varying degrees after inadaptable high intensity exercise. One and two week training could improve erythrocyte deformability, the quantity of band-3 protein and actin after recovery.

CONCLUSIONAlterations of erythrocyte membrane protein after high intensity training could cause the change in erythrocyte membrane structure and hence influenced erythrocyte deformability. That was maybe one of mechanisms of training effecting erythrocyte deformability.

Actins ; metabolism ; Animals ; Anion Exchange Protein 1, Erythrocyte ; metabolism ; Erythrocyte Deformability ; Erythrocyte Indices ; Erythrocyte Membrane ; chemistry ; metabolism ; Physical Conditioning, Animal ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo observe the changes of erythrocyte deformability in rats acclimatized to hypoxia and its molemechanism.

METHODSMale rats were randomly divided into three groups (n = 10): normal control group, acute hypoxia group and hypoxia acclimatization group. Animals were exposed to hypoxia for 0, 1, 28 d, blooded from their hearts after anaesthetized, respectively. Erythrocyte deformability, membrane fluidity, cholesterin and total lipid, lipid components of erythrocyte membrane, erythrocyte membrane ATPase and the concentrations of Na+ and Ca2+ were measured respectively. The two-dimensional electrophoresis maps of the rats erythrocyte membrane protein were achieved. The different protein spots were founded by image master 2D elite and identified by mass spectrum.

RESULTS(1) In acute hypoxia group, the deformability, membrane fluidity, the content of membrane cholesterin and total lipid were declined. The content of phosphatidylserines (PS), sphingomyelin (SM) in erythrocyte membrane lipids were increased, phosphatidylcholine (PC) reduced. The activity of ATP enzymes reduced and the concentration of Na+ and Ca2+ in erythrocyte increased. The two-dimensional electrophoresis maps of the rats erythrocyte membrane protein were achieved. Four of the seven protein spots selected increased and three of them showed no change. (2) In hypoxia acclimatization group, the deformability, membrane fluidity, the content of membrane cholesterin and total lipid were increased than those in acute hypoxia group, similar to normal group. The content of PS, SM in erythrocyte membrane lipids were reduced, PC increased. The activity of ATP enzymes induced and the concentration of Na+ and Ca2+ in erythrocyte increased after hypoxia acclimatization. Four of those protein spots mentioned increase and three declined after hypoxia acclimatization. They were respectively proved by mass spectrum to be alexin binding protein, aquaporin chip, membrane inhibitor reactive lysis, phospholipids scramblase, glucose transferase, aminophospholipid translocases, ATP-dependent floppase, the latter three proteins were associate with the overturning of erythrocyte membrane lipids.

CONCLUSIONAcute hypoxia caused the corresponding damage of erythrocyte deformability, erythrocyte membrane fluidity, erythrocyte membrane proteins erythrocyte expression, the activity of membrane ATPase and the concentration of Na+ and Ca2+ in erythrocyte. The parameters above were improved after hypoxia acclimatization, so hypoxia acclimatization effected positively in the damage to erythrocyte due to acute hypoxia. The three membrane proteins might play important roles in the deformability improved by hypoxia acclimatization, which included phospholipids scramblase, aminophospholipid translocases and ATP-dependent floppase.

Acclimatization ; physiology ; Adenosine Triphosphatases ; metabolism ; Altitude ; Animals ; Calcium ; metabolism ; Erythrocyte Deformability ; physiology ; Erythrocyte Membrane ; metabolism ; Hypoxia ; blood ; physiopathology ; Male ; Membrane Fluidity ; Phospholipid Transfer Proteins ; metabolism ; Rats ; Sodium ; metabolism

PURPOSE: The aim of this study was to determine whether plasma lecithin:cholesterol acyltransferase (pLCAT) and erythrocyte membrane Na(+)-K(+)-ATPase ase (emNaKATPs) activity have a correlation in breast cancer. This study compared these parameters at time points before and after treatment with radiotherapy. METHODS: The levels of pLCAT and emNaKATPs were assessed in 30 patients with breast carcinoma and 20 control subjects. While emNaKATPs was measured with spectrophotometric method, pLCAT levels was measured using a specific enzyme-linked immunosorbent assay. RESULTS: pLCAT levels, both before and after radiotherapy, were found to be decreased in breast cancer patients than in the controls groups (p<0.001 and p<0.001, respectively). Also, pLCAT levels after radiotherapy were found to be decreased in breast cancer patients than the pLCAT levels before radiotherapy (p<0.001). The emNaKATPs activity were higher in the control group than in the breast cancer patients before/after radiotherapy (RT) (p<0.001 and p<0.001, respectively). At the same time, emNaKATPs activity before RT was higher in the breast cancer patients than emNaKATPs activity after RT (p<0.001). There was a significant correlation between pLCAT and emNaKATPs activity in breast cancer patients receiving radiotherapy (r=0.63, p<0.001), but no correlation between in breast cancer patients before RT and control group (r=0.023, p>0.05). CONCLUSION: The results of the present study demonstrated that decreased pLCAT and emNaKATPs activity levels in breast cancer patients after/before RT than control group. In addition, decreased emNaKATPs activity in breast cancer patients receiving radiotherapy may be due to decreased pLCAT concentrations and RT beam. In our opinion, altered activities of pLCAT and emNaKATPs are linked to the treatment effect of radiotherapy. These data may clarify the development of cell membrane dysfunction and lipid metabolism in breast cancer patients receiving radiotherapy.
Breast ; Breast Neoplasms ; Cell Membrane ; Cholesterol ; Erythrocyte Membrane ; Humans ; Lecithins ; Lipid Metabolism ; Plasma ; Sterol O-Acyltransferase

Acute Coronary Syndrome ; metabolism ; pathology ; physiopathology ; Cholesterol ; metabolism ; Erythrocyte Membrane ; metabolism ; Humans

Objective: To report gene mutations in nine patients with hereditary elliptocytosis (HE) and analyze the characteristics of pathogenic gene mutations in HE. Methods: The clinical and gene mutations of nine patients clinically diagnosed with HE at Institute of Hematology & Blood Diseases Hospital from June 2018 to February 2022 were reported and verified by next-generation sequencing to analyze the relationship between gene mutations and clinical phenotypes. Results: Erythrocyte membrane protein gene mutations were detected among nine patients with HE, including six with SPTA1 mutation, one with SPTB mutation, one with EPB41 mutation, and one with chromosome 20 copy deletion. A total of 11 gene mutation sites were involved, including 6 known mutations and 5 novel mutations. The five novel mutations included SPTA1: c.1247A>C (p. K416T) in exon 9, c.1891delG (p. A631fs*17) in exon 15, E6-E12 Del; SPTB: c.154C>T (p. R52W) ; and EPB41: c.1636A>G (p. I546V) . Three of the six patients with the SPTA1 mutation were SPTA1 exon 9 mutation. Conclusion: SPTA1 is the most common mutant gene in patients with HE.
Humans ; Mutation ; Elliptocytosis, Hereditary/metabolism* ; Erythrocyte Membrane/metabolism* ; Exons ; High-Throughput Nucleotide Sequencing ; Spherocytosis, Hereditary/metabolism*

This paper reports an in vivo study on the biophysics characteristics of reticulocytes. Anemia was induced by injection of phenylhydrazine in rabbits. The measurements, including electrophoresis rate, hematolytic rate, fluorescent polarization and the changing anisotropic value, were performed in vivo for 72 hours in the process of reticulocytes growing into erythrocytes. It was shown that there were obvious changes in the biophysics characteristics of reticulocytes in this course. Therefore, the findings are of significance to basic, theoretical and clinical studies.
Anemia, Hemolytic ; blood ; chemically induced ; Animals ; Biophysical Phenomena ; Biophysics ; Erythrocyte Deformability ; Erythrocyte Membrane ; physiology ; Phenylhydrazines ; Rabbits ; Reticulocytes ; metabolism ; physiology

OBJECTIVETo study the changes of the intramembrane protein particles of erythrocyte from Duchenne muscular dystrophy (DMD) patients and the gene carriers and to explore the pathogenesis of DMD and the diagnostic value of erythrocyte freeze-fracture technology.

METHODSThe fixed erythrocyte mass was treated to form replica membrane by means of the freeze-fracture technology. Then the replica membrane was observed and a picture was taken under electron microscope. The protein particles of extracellular face(EF) and protoplasmic face(PF) per square were counted. The statistical comparative analysis was performed.

RESULTSThe protein particle counts of EF face and PF face of erythrocyte membrane from DMD patients and DMD carriers decreased obviously in comparison with the normal control group (P<0.001).

CONCLUSIONThe erythrocyte freeze-fracture electron microscopic technology may serve as a method for accessory examination of diagnosing DMD patients and a method for detecting DMD carriers. This investigation material supplies reliable evidence for the theory of the systemic membrane defect of DMD.

Erythrocyte Membrane ; metabolism ; ultrastructure ; Female ; Heterozygote ; Humans ; Male ; Membrane Proteins ; metabolism ; Microscopy, Electron ; Muscular Dystrophy, Duchenne ; diagnosis ; genetics ; metabolism

OBJECTIVETo explore the hemolytic mechanism of glucose-6-phosphate dehydrogenase (G6PD) deficient erythrocytes in the view of phosphorylation of membrane protein.

METHODSThe alternation of membrane protein phosphorylation and the effect of dithiothreitol (DTT) on protein phosphorylation were analysed by Western blot technique. The activity of phosphotyrosine phosphatase (PTPs) was determined by using p-nitrophenyl phosphate as substrate.

RESULTSTyrosine phosphorylation of band 3 protein was obviously enhanced in G6PD-deficient erythrocytes. The activity of PTPs was low compared to the normal erythrocytes. The level of phosphotyrosine in G6PD-deficient erythrocytes incubated with DTT was almost the same as in those without DTT. The results were consistent with the activity of PTPs.

CONCLUSIONSPTPs activity reduction and tyrosine phosphorylation enhancement induced by oxidation in G6PD deficiency play an important role in erythrocytes hemolysis. However, the alternation of thiol group is not the only factor affecting the activity of PTPs in G6PD-deficient erythrocytes.

Anion Exchange Protein 1, Erythrocyte ; metabolism ; Blotting, Western ; Erythrocyte Membrane ; metabolism ; Glucosephosphate Dehydrogenase Deficiency ; enzymology ; metabolism ; Humans ; Phosphorylation ; Protein Tyrosine Phosphatases ; metabolism ; Tyrosine ; metabolism

This study was aimed to evaluate the effect of benzyl alcohol on trehalose-loading red blood cells (RBCs). The RBCs were incubated in 10, 30, 50 and 100 mmol/L concentrations of benzyl alcohol-trehaloe solution at 4 degrees C for 24 hours. The hemolysis rate of loaded RBCs was detected by using cyanohemoglobin kit, the intracellular trehalose level were assayed by sulfate anthrone method. The results showed that the intracellular trehalose concentration in group with 100 mmol/L benzyl alcohol was 72 +/- 12.98 mmol/L, compared with that in groups of 10, 30 and 50 mmol/L, the statistical difference were significant (p = 0.000); the hemolysis rate of loaded RBCs in group with 100 mmol/L of benzyl alcohol was 17.99 +/- 3.75%, as compared with groups of 10, 30 and 50 mmol/L, the statistical difference was significant (p = 0.000). It is concluded that benzyl alcohol can enhance the intracellular trehalose concentration. As concentration of benzyl alcohol ascends, the intracellular trehalose concentration increases. 100 mmol/L benzyl alcohol may be proper for loading RBCs.
Benzyl Alcohol ; pharmacology ; Blood Preservation ; methods ; Erythrocyte Membrane ; metabolism ; Erythrocytes ; drug effects ; metabolism ; Freeze Drying ; methods ; Humans ; Trehalose ; metabolism ; pharmacology