scholarly journals Uptake and metabolism of dipeptides by human red blood cells

1990 ◽  
Vol 271 (1) ◽  
pp. 133-137 ◽  
Author(s):  
H Lochs ◽  
E L Morse ◽  
S A Adibi
Keyword(s):  
Amino Acids ◽  
Plasma Membrane ◽  
Blood Cell ◽  
Red Blood Cells ◽  
Red Blood Cell ◽  
Blood Cells ◽  
Cell Uptake ◽  
Simple Diffusion ◽  
Human Red Blood Cells ◽  
Wide Range

A function of the abundant cytoplasmic peptidases in red blood cells could be hydrolysis of oligopeptides circulating in plasma. To investigate whether human red blood cells actively transport dipeptides for this purpose, these cells were incubated with 14C-labelled glycylproline, glycylsarcosine, glycine, proline and alanine. There was uptake of each dipeptide, as indicated by their recovery as dipeptides in the cell cytoplasm. However, after a brief time (1-2 min) uptake of dipeptides abruptly ceased, while that of amino acids continued. As a result, after 30 min red blood cell uptake of amino acids was 5-13-fold greater than that of any dipeptide. Investigation of intracellular contents after 1 min of incubation revealed different metabolism for different dipeptides. The composition of intracellular radioactivity was 19-71% as intact dipeptides, 0-20% as free amino acids and 8-77% as neither dipeptides nor constituent amino acids. Investigation of the mechanism of dipeptide uptake by red blood cells showed: (1) a lack of hydrolysis by the plasma membrane, (2) no non-specific binding to the plasma membrane, and (3) a lack of saturation over a wide range of concentrations (0.05-50 mM). The data suggest that the mechanism of uptake of trace amounts of dipeptides by human red blood cells is either by simple diffusion or by a carrier system which has a very weak affinity for dipeptides. Upon entry, depending on the molecular structure, dipeptides are either hydrolysed or transformed into new compounds. The red blood cell uptake, however, does not appear to play any appreciable role in clearance of dipeptides from the plasma in the human.

scholarly journals Na- and Cl-dependent glycine transport in human red blood cells and ghosts. A study of the binding of substrates to the outward-facing carrier.

1989 ◽  
Vol 93 (2) ◽  
pp. 321-342 ◽  
Author(s):  
P A King ◽  
R B Gunn
Keyword(s):  
Blood Cell ◽  
Red Blood Cells ◽  
Red Blood Cell ◽  
Blood Cells ◽  
Human Red Blood Cells ◽  
Glycine Transport ◽  
Rapid Equilibrium ◽  
Cis And Trans ◽  
Best Fit ◽  
Na Uptake

Na- and Cl-dependent glycine transport was investigated in human red blood cells. The effects of the carrier substrates (Na, Cl, and glycine) on the glycine transport kinetics were studied with the goal of learning more about the mechanism of transport. The K1/2-gly was 100 microM and the Vmax-gly was 109 mumol/kg Hb.h. When cis Na was lowered (50 mM) the K1/2-gly increased and the Vmax-gly decreased, which was consistent with a preferred order of rapid equilibrium loading of glycine before Na. Na-dependent glycine influx as a function of Na concentration was sigmoidal, and direct measurement of glycine and Na uptake indicated a stoichiometry of 2 Na:1 glycine transported. The sigmoidal response of glycine influx to Na concentration was best fit by a model with ordered binding of Na, the first Na with a high K1/2 (greater than 250 mM), and the second Na with a low K1/2 (less than 10.3 mM). In the presence of low Cl (cis and trans 5 mM), the K1/2-gly increased and the Vmax-gly increased. The Cl dependence displayed Michaelis-Menten kinetics with a K1/2-Cl of 9.5 mM. At low Cl (5 mM Cl balanced with NO3), the glycine influx as a function of Na showed the same stoichiometry and Vmax-Na but a decreased affinity of the carrier for Na. These data suggested that Cl binds to the carrier before Na. Experiments comparing influx and efflux rates of transport using red blood cell ghosts indicated a functional asymmetry of the transporter. Under the same gradient conditions, Na- and Cl-dependent glycine transport functioned in both directions across the membrane but rates of efflux were 50% greater than rates of influx. In addition, the presence of trans substrates modified influx and efflux differently. Trans glycine largely inhibited glycine efflux in the absence or presence of trans Na; trans Na largely inhibited glycine influx and this inhibition was partially reversed when trans glycine was also present. A model for the binding of these substrates to the outward-facing carrier is presented.

scholarly journals Uji Aktivitas Lektin Biji Kebiul terhadap Kecepatan Penggumpalan Sel Darah Merah Manusia dalam Kondisi Patologis dan Implementasinya sebagai Modul Pembelajaran Kimia

2018 ◽  
Vol 2 (2) ◽  
Author(s):  
Yeni Trianah
Keyword(s):  
Blood Cell ◽  
Red Blood Cells ◽  
Molecular Mass ◽  
Red Blood Cell ◽  
Blood Cells ◽  
Seed Extract ◽  
Relative Molecular Mass ◽  
Human Red Blood Cells ◽  
Sds Page ◽  
Post Test

ABSTRACT[Lectin activities of kebiul seeds to the red blood cell agglutination speed in pathological condition and its implementation as a chemical learning module]. The purposes of this research were to determine: 1) the relative moleculer mass protein that behaves as a lectin in the seed extract kebiul , 2) the velocity of red blood cell clumping influenced by seed lectin kebiul, 3) know the difference student results on protein taught modules and a without modules taught at the College of Teacher Training and Education Teachers Association of the Republic of Indonesia (STKIP-PGRI) Lubuklinggau. Extraction of seeds Kebiul carried out in the a cold buffer solution with pH 7.4 and plus 60% saturated ammonium sulfat (salting out method), and made in four concentrations, namely : 2%, 4%, 6% and 8%. Then tested the activity of seed lectin kebiul to speed clotting of human red blood cells in pathological conditions. To determine the relative molecular mass protein that behaves as a lectin in the seed extract kebiul SDS PAGE electrophoresis performed 1-D. The experiment were then implemented on the material of protein biochemistry using modules. The results of the research showed that on the concentration of 8% the velocity of the clumping of a human red blood cells hypertension most of the highest, the relative molecular mass which behaves as a lectin protein electrophoresis results of 1-D SDS PAGE obtained by a three protein bands in the range of moleculer weights 80, 128 and 144 kDa. The Results of the implementation of the experimental class showed an average `post test value was 95 and the post test control class 69.41. There are differences in students' learning about protein for students who are taught by module and who are taught without module.Keywords: Lectin; agglutination; blood; 1-D SDS PAGE; learning outcomes.

scholarly journals The Entry of Sodium into Human Red Blood Cells in Vivo

1966 ◽  
Vol 50 (1) ◽  
pp. 75-88 ◽  
Author(s):  
L. J. Beilin ◽  
D. Eyeions ◽  
G. Hatcher ◽  
G. J. Knight ◽  
A. D. Munro-Faure ◽  
...  
Keyword(s):  
Blood Cell ◽  
Red Blood Cells ◽  
Red Blood Cell ◽  
Blood Cells ◽  
Compartmental Analysis ◽  
Analogue Computer ◽  
Packed Red Blood Cells ◽  
Human Red Blood Cells ◽  
In Series

The kinetics of sodium, movement into human red blood cells has been studied in vivo with 24Na. When human serum albumin-131I is used to measure the percentage of plasma trapped in the packed red blood cells after centrifugation, approximately 30 % of red blood cell sodium is found to equilibrate immediately with plasma. It is concluded that this immediately exchangeable compartment of red blood cell sodium is an experimental artefact, associated with the use of labeled albumin for measuring plasma trapping. This immediately exchangeable fraction disappears when sucrose-14C is used to measure plasma trapping. The experimental results were examined by compartmental analysis, using an analogue computer. The results obtained, when plasma trapping was measured with sucrose-14C could be simulated by the use of models containing two compartments, arranged in series or in parallel. The errors of the techniques used and the possible physical basis for the results are discussed.

scholarly journals Red blood cell volume can be independently determined in vitro using sheep and human red blood cells labeled at different densities of biotin

Transfusion ◽  
2009 ◽  
Vol 49 (6) ◽  
pp. 1178-1185 ◽  
Author(s):  
Donald M. Mock ◽  
Nell I. Matthews ◽  
Ronald G. Strauss ◽  
Leon F. Burmeister ◽  
Robert Schmidt ◽  
...  
Keyword(s):  
Blood Cell ◽  
Red Blood Cells ◽  
Cell Volume ◽  
Red Blood Cell ◽  
Blood Cells ◽  
Human Red Blood Cells

scholarly journals Uji Aktivitas Lektin Biji Kebiul terhadap Kecepatan Penggumpalan Sel Darah Merah Manusia dalam Kondisi Patologis dan Implementasinya sebagai Modul Pembelajaran Kimia

2018 ◽  
Vol 2 (2) ◽  
pp. 214-221
Author(s):  
Yeni Trianah
Keyword(s):  
Blood Cell ◽  
Red Blood Cells ◽  
Molecular Mass ◽  
Red Blood Cell ◽  
Blood Cells ◽  
Seed Extract ◽  
Relative Molecular Mass ◽  
Human Red Blood Cells ◽  
Sds Page ◽  
Post Test

ABSTRACT[Lectin activities of kebiul seeds to the red blood cell agglutination speed in pathological condition and its implementation as a chemical learning module]. The purposes of this research were to determine: 1) the relative moleculer mass protein that behaves as a lectin in the seed extract kebiul , 2) the velocity of red blood cell clumping influenced by seed lectin kebiul, 3) know the difference student results on protein taught modules and a without modules taught at the College of Teacher Training and Education Teachers Association of the Republic of Indonesia (STKIP-PGRI) Lubuklinggau. Extraction of seeds Kebiul carried out in the a cold buffer solution with pH 7.4 and plus 60% saturated ammonium sulfat (salting out method), and made in four concentrations, namely : 2%, 4%, 6% and 8%. Then tested the activity of seed lectin kebiul to speed clotting of human red blood cells in pathological conditions. To determine the relative molecular mass protein that behaves as a lectin in the seed extract kebiul SDS PAGE electrophoresis performed 1-D. The experiment were then implemented on the material of protein biochemistry using modules. The results of the research showed that on the concentration of 8% the velocity of the clumping of a human red blood cells hypertension most of the highest, the relative molecular mass which behaves as a lectin protein electrophoresis results of 1-D SDS PAGE obtained by a three protein bands in the range of moleculer weights 80, 128 and 144 kDa. The Results of the implementation of the experimental class showed an average `post test value was 95 and the post test control class 69.41. There are differences in students' learning about protein for students who are taught by module and who are taught without module.Keywords: Lectin; agglutination; blood; 1-D SDS PAGE; learning outcomes.

scholarly journals Initial stages of influenza hemagglutinin-induced cell fusion monitored simultaneously by two fluorescent events: cytoplasmic continuity and lipid mixing.

1989 ◽  
Vol 109 (1) ◽  
pp. 113-122 ◽  
Author(s):  
D P Sarkar ◽  
S J Morris ◽  
O Eidelman ◽  
J Zimmerberg ◽  
R Blumenthal
Keyword(s):  
Blood Cell ◽  
Red Blood Cells ◽  
Red Blood Cell ◽  
Blood Cells ◽  
Fluorescent Dyes ◽  
Water Soluble ◽  
Ph Profile ◽  
Influenza Hemagglutinin ◽  
Human Red Blood Cells ◽  
Membrane Bound

We have monitored the mixing of both aqueous intracellular and membrane-bound fluorescent dyes during the fusion of human red blood cells to influenza hemagglutinin-expressing fibroblasts using fluorescence spectroscopy and low light, image-enhanced video microscopy. The water-soluble fluorescent dye, N-(7-nitrobenzofurazan-4-yl)taurine, was incorporated into intact human red blood cells. The fluorescence of the dye in the intact red blood cell was partially quenched by hemoglobin. The lipid fluorophore, octadecylrhodamine, was incorporated into the membrane of the same red blood cell at self-quenching concentrations (Morris, S. J., D. P. Sarkar, J. M. White, and R. Blumenthal. 1989. J. Biol. Chem. 264: 3972-3978). Fusion, which allowed movement of the water-soluble dye from the cytoplasm of the red blood cell into the hemagglutinin-expressing fibroblasts, and movement of octadecylrhodamine from membranes of red blood cell to the plasma membrane of the fibroblasts, was observed by fluorescence microscopy as a spatial relocation of dyes, and monitored by spectrofluorometry as an increase in fluorescence. Upon lowering the pH below 5.4, fluorescence increased after a delay of about 30 s at 37 degrees C, reaching a maximum within 3 min. The kinetics, pH profile, and temperature dependence were similar for both fluorescent events measured simultaneously, indicating that influenza hemagglutinin-induced fusion rapidly establishes bilayer continuity and exchange of cytoplasmic contents.

scholarly journals The Measurement of Sodium Concentration in Human Red Blood Cells

1966 ◽  
Vol 50 (1) ◽  
pp. 61-74 ◽  
Author(s):  
L. J. Beilin ◽  
G. J. Knight ◽  
A. D. Munro-Faure ◽  
J. Anderson
Keyword(s):  
Blood Cell ◽  
Red Blood Cells ◽  
Red Blood Cell ◽  
Blood Cells ◽  
Sodium Concentration ◽  
Plasma Sodium ◽  
Human Red Blood Cells ◽  
Relative Centrifugal Force ◽  
The Difference ◽  
Extracellular Sodium

Experiments are described which indicate that iodinated human serum albumin underestimates the amount of extracellular sodium trapped in the packed layer of red blood cells, when cells and plasma are separated by centrifugation. Sucrose-14C also underestimates the amount of trapped extracellular sodium, but the difference between the percentages of sucrose-14C and extracellular sodium trapped is constant and independent of mean relative centrifugal force. It is concluded that human red blood cell sodium concentration can be measured with accuracy (a) if trapped plasma sodium is estimated with radioisotopes of sodium and a correction made for entry of sodium into the cells, providing cells and plasma can be separated rapidly; (b) by the use of sucrose as a standard plasma marker to derive the amount of trapped plasma sodium; (c) by washing the cells with sodium-free solutions. Reported values for red blood cell sodium concentration in healthy adults are critically reviewed.

scholarly journals Stereospecific modulation of the calcium channel in human erythrocytes by cholesterol and its oxidized derivatives

1985 ◽  
Vol 227 (1) ◽  
pp. 105-112 ◽  
Author(s):  
L Neyses ◽  
R Locher ◽  
M Stimpel ◽  
R Streuli ◽  
W Vetter
Keyword(s):  
Blood Cell ◽  
Calcium Channel ◽  
Red Blood Cells ◽  
Red Blood Cell ◽  
Blood Cells ◽  
Calcium Influx ◽  
Model System ◽  
Cholesterol Depletion ◽  
Human Red Blood Cells ◽  
L 22

To study the effect of cholesterol and its pathophysiologically important oxidized derivatives (OSC) on the calcium entry channel, the human red blood cell was used as a model system. The calcium ejecting adenosinetriphosphatase (ATPase) was inhibited by vanadate. The cells were loaded with OSC at concentrations between 1.25 × 10(-5) and 25 × 10(-5) mol/l. 22-Hydroxycholesterol, cholestan-3 beta,5 alpha,6 beta-triol, 5 alpha-cholestan-3 beta-ol,3 beta,5 alpha-dihydroxycholestan-6-one and 3 beta-hydroxy-5 alpha-cholestan-7-one stimulated 45Ca2+ influx by up to almost 90%, whereas 25-hydroxycholesterol, 7 beta-hydroxycholesterol, 20 alpha-hydroxycholesterol and 7-oxocholesterol inhibited influx by up to 75%. Both stimulation and inhibition were dependent on the amount of OSC incorporated into the membrane. More than 90% of the total modification of calcium influx by OSC was accounted for by an influence on the nitrendipine-inhibitable part of influx. Enrichment of cholesterol in the membrane greatly stimulated, and cholesterol depletion inhibited, Ca2+ influx. These results demonstrate that cholesterol and its oxidized derivatives are able to modulate the calcium channel in human red blood cells in a highly stereospecific manner.

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