Human erythrocytes are affected in vitro by flavonoids of Aristotelia chilensis (Maqui) leaves

ABSTRACT The red cell triiodothyronine uptake technique as used in our hospital is described. Incubation time is of almost no importance. The temperature during incubation should be 37° C. Further improvement of the technique is obtained when all blood samples are brought up to 40 % haematocrit prior to incubation. Clinical results are discussed. It is yet too early to give a definite assessment of its clinical value, but it is definitely superior to the measurement of the BMR.

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Preparation and In Vitro Evaluation of Resealed Erythrocytes as A New Trend in Treatment of Asthma

International Journal of Drug Delivery Technology ◽

10.25258/ijddt.v6i3.8889 ◽

2016 ◽

Vol 6 (3) ◽

Author(s):

Mohammed Ibrahim ◽

Alaa Zaky ◽

Mohsen Afouna ◽

Ahmed Samy

Keyword(s):

In Vitro Release ◽

Human Erythrocytes ◽

The Body ◽

Blood Levels ◽

Time Interval ◽

Burst Release ◽

Prolonged Release ◽

Nocturnal Asthma ◽

Carrier Erythrocytes

Carrier erythrocytes are emerging as one of the most promising biological drug delivery systems investigated in recent decades. Beside its biocompatibility, biodegradability and ability to circulate throughout the body, it has the ability to perform extended release system of the drug for a long period. The ultimate goal of this study is to introduce a new carrier system for Salbutamol, maintaining suitable blood levels for a long time, as atrial to resolve the problems of nocturnal asthma medication Therefore in this work we study the effect of time, temperature as well as concentration on the loading of salbutamol in human erythrocytes to be used as systemic sustained release delivery system for this drug. After the loading process is performed the carrier erythrocytes were physically and cellulary characterized. Also, the in vitro release of salbutamol from carrier erythrocytes was studied over time interval. From the results it was found that, human erythrocytes have been successfully loaded with salbutamol using endocytosis method either at 25 Co or at 37 Co . The highest loaded amount was 3.5 mg/ml and 6.5 mg/ml respectively. Moreover, the percent of cells recovery is 90.7± 1.64%. Hematological parameters and osmotic fragility behavior of salbutamol loaded erythrocytes were similar that of native erythrocytes. Scanning electron microscopy demonstrated that the salbutamol loaded cells has moderate change in the morphology. Salbutamol releasing from carrier cell was 43% after 36 hours in phosphate buffer saline. The releasing pattern of the drug from loaded erythrocytes showed initial burst release in the first hour followed by a very slow release, obeying zero order kinetics. It concluded that salbutamol is successfully entrapped into erythrocytes with acceptable loading parameters and moderate morphological changes, this suggesting that erythrocytes can be used as prolonged release carrier for salbutamol.

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In Vitro Incorporation of GPI-Anchored Proteins Into Human Erythrocytes and Their Fate in the Membrane

Blood ◽

10.1182/blood.v91.5.1784 ◽

1998 ◽

Vol 91 (5) ◽

pp. 1784-1792 ◽

Cited By ~ 33

Author(s):

Gianluca Civenni ◽

Samuel T. Test ◽

Urs Brodbeck ◽

Peter Bütikofer

Keyword(s):

Membrane Vesicle ◽

Human Erythrocytes ◽

Membrane Extraction ◽

Membrane Microdomains ◽

Membrane Insertion ◽

Vesicle Formation ◽

Calcium Loading ◽

Lipid Moiety ◽

Triton X

Abstract In many different cells, glycosylphosphatidylinositol (GPI)-anchored molecules are clustered in membrane microdomains that resist extraction by detergents at 4°C. In this report, we identified the presence of such domains in human erythrocytes and examined the ability of exogenously-added GPI-anchored molecules to colocalize with the endogenous GPI-anchored proteins in these detergent-insoluble complexes. We found that the addition to human erythrocytes of three purified GPI-anchored proteins having different GPI lipid moieties resulted in their efficient and correct incorporation into the membrane. The extent of membrane insertion was dependent on the intactness of the GPI lipid moiety. However, unlike the endogenous GPI-anchored proteins, the in vitro incorporated GPI molecules were not resistant to membrane extraction by Triton X-100 at 4°C. In addition, in contrast to the endogenous GPI-anchored proteins, they were not preferentially released from erythrocytes during vesiculation induced by calcium loading of the cells. These results suggest that in vitro incorporated GPI-linked molecules are excluded from pre-existing GPI-enriched membrane areas in human erythrocytes and that these microdomains may represent the sites of membrane vesicle formation.

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Surface-Engineered Dendrimeric Nanoconjugates for Macrophage-Targeted Delivery of Amphotericin B: Formulation Development andIn VitroandIn VivoEvaluation

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.04213-14 ◽

2015 ◽

Vol 59 (5) ◽

pp. 2479-2487 ◽

Cited By ~ 40

Author(s):

Keerti Jain ◽

Ashwni Kumar Verma ◽

Prabhat Ranjan Mishra ◽

Narendra Kumar Jain

Keyword(s):

Drug Release ◽

Amphotericin B ◽

Human Erythrocytes ◽

Antileishmanial Activity ◽

Cell Uptake ◽

Antiparasitic Activity ◽

Content Type ◽

Drug Localization

ABSTRACTThe present study aimed to develop an optimized dendrimeric delivery system for amphotericin B (AmB). Fifth-generation (5.0G) poly(propylene imine) (PPI) dendrimers were synthesized, conjugated with mannose, and characterized by use of various analytical techniques, including Fourier transform infrared spectroscopy (FTIR),1H nuclear magnetic resonance (1H-NMR) spectroscopic analysis, and atomic force microscopy (AFM). Mannose-conjugated 5.0G PPI (MPPI) dendrimers were loaded with AmB and evaluated for drug loading efficiency,in vitrodrug release profile, stability, hemolytic toxicity to human erythrocytes, cytotoxicity to and cell uptake by J774A.1 macrophage cells, antiparasitic activity against intracellularLeishmania donovaniamastigotes,in vivopharmacokinetic and biodistribution profiles, drug localization index, toxicity, and antileishmanial activity. AFM showed the nanometric size of the MPPI dendrimers, with a nearly globular architecture. The conjugate showed a good entrapment efficiency for AmB, along with pH-sensitive drug release. Highly significant reductions in toxicity toward human erythrocytes and macrophage cells, without compromising the antiparasitic activity of AmB, were observed. The dendrimeric formulation of AmB showed a significant enhancement of the parasiticidal activity of AmB toward intramacrophagicL. donovaniamastigotes. In thein vitrocell uptake studies, the formulation showed selectivity toward macrophages, with significant intracellular uptake. Further pharmacokinetic and organ distribution studies elucidated the controlled delivery behavior of the formulation. The drug localization index was found to increase significantly in macrophage-rich organs.In vivostudies showed a biocompatible behavior of MPPIA, with negligible toxicity even at higher doses, and promising antileishmanial activity. From the results, we concluded that surface-engineered dendrimers may serve as optimized delivery vehicles for AmB with enhanced activity and low or negligible toxicity.

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Uptake of labelled amino acids into human erythrocytes in vitro

Clinica Chimica Acta ◽

10.1016/0009-8981(65)90063-x ◽

1965 ◽

Vol 11 (3) ◽

pp. 197-204 ◽

Cited By ~ 4

Author(s):

K.B. Björnesjö

Keyword(s):

Amino Acids ◽

Human Erythrocytes

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Anaerobic Glycolysis in Normal Human Erythrocytes Incubated in Vitro with Sodium Salicylate

Clinical Science ◽

10.1042/cs0490375 ◽

1975 ◽

Vol 49 (5) ◽

pp. 375-384

Author(s):

N. Worathumrong ◽

A. J. Grimes

Keyword(s):

Sodium Salicylate ◽

Lactate Production ◽

Glucose Consumption ◽

Human Erythrocytes ◽

Anaerobic Glycolysis ◽

Initial Stimulus ◽

Sodium Efflux ◽

Normal Human ◽

Concentration Changes

1. Some effects of sodium salicylate upon anaerobic glycolysis have been studied in normal human erythrocytes incubated for up to 6 h at 37°C in autologous sera. 2. Both glucose consumption and lactate production were stimulated by concentrations of salicylate up to 60 mmol/l but at the highest concentration used (90 mmol/l) an initial stimulus was followed by inhibition of glycolysis. 3. Losses occurred of adenosine 5′-triphosphate (ATP), adenosine 5′-diphosphate (ADP) and adenosine 5′-phosphate (AMP) at higher concentrations of salicylate and there was a concomitant increase of inorganic phosphate. 4. Other phosphate esters underwent concentration changes at higher concentrations of salicylate that reflected inadequate concentrations of ATP for glycolysis. 5. The rates of sodium efflux from, and potassium influx into, erythrocytes were unaffected by the presence of salicylate at concentrations sufficient to stimulate glycolysis.

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Antigenicity of the infected-erythrocyte and merozoite surfaces in Falciparum malaria.

Journal of Experimental Medicine ◽

10.1084/jem.150.5.1241 ◽

1979 ◽

Vol 150 (5) ◽

pp. 1241-1254 ◽

Cited By ~ 62

Author(s):

S G Langreth ◽

R T Reese

Keyword(s):

Plasmodium Falciparum ◽

Falciparum Malaria ◽

Infected Erythrocyte ◽

Falciparum Infection ◽

Human Erythrocytes ◽

Cross Linking ◽

Common Antigens

The antigenicity of altered structures induced by Plasmodium falciparum in the membranes of infected Aotus monkey and human erythrocytes was examined. Antisera were obtained from monkeys made immune to malaria. Bound antibodies were shown to be localized on the knob protrusions of infected erythrocytes of both human and monkey origin and from both in vitro and in vivo infections. Therefore, P. falciparum infection has produced similar antigenic changes in the erythrocyte surfaces of both man and monkey. Uninfected erythrocytes and all knobless-infected erythrocytes bound no antibody from immune sera. Strains of P. falciparum from widely different geographic areas that were cultured in vitro in human erythrocytes induced structures (knobs) which have common antigenicity. Merozoites were agglutinated by cross-linking of their cell coats when incubated with immune sera. The binding of ferritin-labeled antibody was heavy on the coats of both homologous and heterologous strains of the parasite, indicating that the merozoite surfaces of these strains share common antigens.

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Acrylamide-induced oxidative stress in human erythrocytes

Human & Experimental Toxicology ◽

10.1177/0960327109350664 ◽

2009 ◽

Vol 28 (10) ◽

pp. 611-617 ◽

Cited By ~ 30

Author(s):

Betul Catalgol ◽

Gül Özhan ◽

Buket Alpertunga

Keyword(s):

Oxidative Stress ◽

Reduced Glutathione ◽

Human Erythrocytes ◽

Antioxidant Enzyme Activities ◽

Total Glutathione ◽

Sod Activity ◽

Spectrophotometric Methods ◽

Low Concentrations ◽

Different Doses

Acrylamide (AA), a widely used industrial chemical, is shown to be neurotoxic, mutagenic and carcinogenic. This study was carried out to investigate the effects of different doses of AA on lipid peroxidation (LPO), haemolysis, methaemoglobin (MetHb) and antioxidant system in human erythrocytes in vitro. Erythrocyte solutions were incubated with 0.10, 0.25, 0.50 and 1.00 mM of AA at 37°C for 1 hour. At the end of the incubation, malondialdehyde (MDA), an end product of LPO, was determined by liquid chromatography (LC) while total glutathione, reduced glutathione (GSH) levels, activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) enzymes and the rates of haemolysis and MetHb were determined by spectrophotometric methods. All of the studied concentrations of AA increased MetHb formation and SOD activity, and induced MDA formation and haemolysis due to the destruction of erythrocyte cell membrane. AA caused a decrease in the activities of GSH-Px, CAT and GSH levels. However, these effects of AA were seen only at higher concentrations than AA intake estimated for populations in many countries. We suggest that LPO process may not be involved in the toxic effects of AA in low concentrations, although the present results showed that the studied concentrations of AA exert deteriorating effects on antioxidant enzyme activities, LPO process and haemolysis.

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Age-dependent changes in volume and haemoglobin content of erythrocytes in the carp (Cyprinus carpio L.)

Journal of Experimental Biology ◽

10.1242/jeb.141.1.133 ◽

1989 ◽

Vol 141 (1) ◽

pp. 133-149 ◽

Cited By ~ 2

Author(s):

W. Speckner ◽

J. F. Schindler ◽

C. Albers

Keyword(s):

Gel Filtration ◽

Linear Increase ◽

Human Erythrocytes ◽

Main Peak ◽

Red Cell ◽

Human Haemoglobin ◽

Cell Fractions ◽

Haemoglobin Content

Carp erythrocytes were fractionated by angle-head centrifugation which yielded fractions with a linear increase in density. Haematological examinations revealed that the heavier red blood cells of carp had greater volumes (MCV), more haemoglobin (MCH) and higher haemoglobin concentrations (MCHC) than light ones. The same experiments with human red cell fractions yielded a decrease in MCV, constant MCH and an increase in MCHC. Haemoglobin content in individual erythrocytes was also determined by scanning stage absorbance cytophotometry to establish the frequency distribution of the cellular haemoglobin contents. In carp, the distribution was symmetrical with the means increasing with density. No such change with cell density was found in human erythrocytes. Both carp and human erythrocytes incorporated [2-14C]glycine in vitro. After gel filtration, radioactivity was detected in carp, but not in human, haemoglobin fractions. 14C was found in all three haemoglobin fractions, obtained by isoelectric focusing, and was present in the haem and in the globin. [2-14C]glycine-labelled erythrocytes were reinjected into chronically cannulated carp and followed in vivo for several months. With time, the main peak of scintillation counts shifted from red cell fractions of low to high density. This is considered as evidence that density and age of red cells in carp are positively correlated and that erythrocytes can synthesize haemoglobin while circulating in the peripheral blood.

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