Role of RhAG and AQP1 in NH3 and CO2 gas transport in red cell ghosts: a stopped-flow analysis

2006 ◽  
Vol 13 (1-2) ◽  
pp. 117-122 ◽  
Author(s):  
P. Ripoche ◽  
D. Goossens ◽  
O. Devuyst ◽  
P. Gane ◽  
Y. Colin ◽  
...  
Keyword(s):  
Gas Transport ◽  
Flow Analysis ◽  
Stopped Flow ◽  
Red Cell ◽  
Co2 Gas

The orientation of sickle hemoglobin fibers within fascicles

1988 ◽  
Vol 46 ◽  
pp. 400-401
Author(s):  
Christopher A. Miller ◽  
Bridget Carragher ◽  
William A. McDade ◽  
Robert Josephs
Keyword(s):  
Sickle Cell ◽  
Sickle Cell Anemia ◽  
Relative Orientation ◽  
Unit Cell ◽  
Red Cell ◽  
High Ph ◽  
Sickle Hemoglobin ◽  
Polar Crystal ◽  
Helical Configuration

Highly ordered bundles of deoxyhemoglobin S (HbS) fibers, termed fascicles, are intermediates in the high pH crystallization pathway of HbS. These fibers consist of 7 Wishner-Love double strands in a helical configuration. Since each double strand has a polarity, the odd number of double strands in the fiber imparts a net polarity to the structure. HbS crystals have a unit cell containing two double strands, one of each polarity, resulting in a net polarity of zero. Therefore a rearrangement of the double strands must occur to form a non-polar crystal from the polar fibers. To determine the role of fascicles as an intermediate in the crystallization pathway it is important to understand the relative orientation of fibers within fascicles. Furthermore, an understanding of fascicle structure may have implications for the design of potential sickling inhibitors, since it is bundles of fibers which cause the red cell distortion responsible for the vaso-occlusive complications characteristic of sickle cell anemia.

Red cell oxygen affinity in fetal sheep: role of 2,3-DPG and adult hemoglobin

1978 ◽  
Vol 45 (1) ◽  
pp. 7-10 ◽  
Author(s):  
H. Bard ◽  
J. C. Fouron ◽  
J. E. Robillard ◽  
A. Cornet ◽  
M. A. Soukini
Keyword(s):  
Red Blood Cells ◽  
Blood Cells ◽  
Oxygen Affinity ◽  
Fetal Life ◽  
Red Cell ◽  
Adult Type ◽  
Fetal Sheep ◽  
Adult Hemoglobin ◽  
Relationship Of

Studies were carried out during fetal life in sheep to determine the relationship of 2,3-diphosphoglycerate (DPG), the intracellular red cell and extracellular pH, and the switchover to adult hemoglobin synthesis in regulating the position of the fetal red cell oxygen-affinity curve in utero. Adult hemoglobin first appeared near 120 days of gestation. The mean oxygen tension at which hemoglobin is half saturated (P50) prior to 120 days of gestation remained constant at 13.9 +/- 0.3 (SD) Torr and then increased gradually as gestation continued, reaching 19 Torr at term. During the interval of fetal life studied, the level of DPG was 4.43 +/- 1.63 (SD) micromol/g Hb and the deltapH between plasma and red blood cells was 0.227 +/- 0.038 (SD); neither was affected by gestational age. The decrease in the red cell oxygen affinity after 120 days of gestation ocrrelated with the amount of adult hemoglobin present in the fetus (r = 0.78; P less than 0.001). This decrease can be attributed only to the amount of the adult-type hemoglobin present, and not to DPG, or to changes in the deltapH between plasma and red blood cells, because both remained stable during the last trimester.

Fibrinogen, Platelet and Red Cell Kinetics in Mice Bearing an Experimental Tumor

1975 ◽  
Author(s):  
A. Poggi ◽  
N. Polentarutti ◽  
M. B. Donati ◽  
G. de Gaetano ◽  
S. Garattini
Keyword(s):  
Cell Kinetics ◽  
Fibrinogen Level ◽  
Low Grade ◽  
Red Cell ◽  
Experimental Tumor ◽  
Tumor Implantation ◽  
The Third ◽  
Red Cell Survival ◽  
Observation Period

In view of the possible role of platelets and coagulation mechanisms in the growth and dissemination of solid tumors, a number of haematological parameters have been followed during development of an experimental syngeneic tumor in mice (Lewis Lung Carcinoma, 3LL). This tumor, when transplanted intramuscularly in C57,B1/6 mice, grows locally and gives spontaneous metastases to the lungs. The transplanted animals survive for about 4 weeks. Metastases are visible since the third week. A slight but constant increase in plasma fibrinogen level and a marked thrombocytopenia were observed starting during the second week after tumor implantation. No other significant changes in coagulation and fibrinolysis parameters were found. Moreover, the animals developed a marked haemolytic anaemia, possibly microangiopathic in origin. 125I-fibrinogen survival was decreased of about 20% during the second week after tumor implantation and was not further reduced later on. Fibrinogen turnover was accelerated since the second week and was further increased thereafter, being more than doubled at the end of the third week. Labelled fibrinogen accumulated in the primary tumor and in the lungs; its rats of disappearance from the tumor was much slower than from lungs or blood. These data suggest the occurrence of a low-grade, localized fibrinogen consumption (intravascular coagulation ?). 51Cr-platelet survival was not modified throughout the observation period, whereas platelet turnover was markedly reduced since the end of the second week, suggesting a defective platelet production. 51Cr-red cell survival was drastically reduced to about 30% of controls starting from the second week, whereas labelled red cell turnover was almost doubled. The pathogenetic relevance of the observed modifications in the processes of grwoth and dissemination of 3 LL remains to be established.(Supported by Grant NIH-PHRB-IRO1 CA 12764–01.

Radiation-induced red cell damage: role of reactive oxygen species

Transfusion ◽  
1997 ◽  
Vol 37 (2) ◽  
pp. 160-165 ◽  
Author(s):  
AJ Anand ◽  
WH Dzik ◽  
A Imam ◽  
SM Sadrzadeh
Keyword(s):  
Reactive Oxygen Species ◽  
Cell Damage ◽  
Reactive Oxygen ◽  
Red Cell ◽  
Oxygen Species ◽  
Radiation Induced

scholarly journals Ca2+-driven intestinal HCO3− secretion and CaCO3 precipitation in the European flounder in vivo: influences on acid-base regulation and blood gas transport

2010 ◽  
Vol 298 (4) ◽  
pp. R870-R876 ◽  
Author(s):  
Christopher A. Cooper ◽  
Jonathan M. Whittamore ◽  
Rod W. Wilson
Keyword(s):  
Teleost Fish ◽  
Gas Transport ◽  
Driving Forces ◽  
Marine Teleost ◽  
Acid Excretion ◽  
Acid Base ◽  
Marine Teleost Fish ◽  
Net Acid Excretion

Marine teleost fish continuously ingest seawater to prevent dehydration and their intestines absorb fluid by mechanisms linked to three separate driving forces: 1) cotransport of NaCl from the gut fluid; 2) bicarbonate (HCO3−) secretion and Cl− absorption via Cl−/HCO3− exchange fueled by metabolic CO2; and 3) alkaline precipitation of Ca2+ as insoluble CaCO3, which aids H2O absorption). The latter two processes involve high rates of epithelial HCO3− secretion stimulated by intestinal Ca2+ and can drive a major portion of water absorption. At higher salinities and ambient Ca2+ concentrations the osmoregulatory role of intestinal HCO3− secretion is amplified, but this has repercussions for other physiological processes, in particular, respiratory gas transport (as it is fueled by metabolic CO2) and acid-base regulation (as intestinal cells must export H+ into the blood to balance apical HCO3− secretion). The flounder intestine was perfused in vivo with salines containing 10, 40, or 90 mM Ca2+. Increasing the luminal Ca2+ concentration caused a large elevation in intestinal HCO3− production and excretion. Additionally, blood pH decreased (−0.13 pH units) and plasma partial pressure of CO2 (Pco2) levels were elevated (+1.16 mmHg) at the highest Ca perfusate level after 3 days of perfusion. Increasing the perfusate [Ca2+] also produced proportional increases in net acid excretion via the gills. When the net intestinal flux of all ions across the intestine was calculated, there was a greater absorption of anions than cations. This missing cation flux was assumed to be protons, which vary with an almost 1:1 relationship with net acid excretion via the gill. This study illustrates the intimate link between intestinal HCO3− production and osmoregulation with acid-base balance and respiratory gas exchange and the specific controlling role of ingested Ca2+ independent of any other ion or overall osmolality in marine teleost fish.

pH environmental of red cells in the spleen

1976 ◽  
Vol 231 (6) ◽  
pp. 1672-1678 ◽  
Author(s):  
MJ Levesque ◽  
AC Groom
Keyword(s):  
Splenic Tissue ◽  
Red Cells ◽  
Red Cell ◽  
Cat Spleen ◽  
Flow Through ◽  
Red Pulp ◽  
Reduced Flow

Intrasplenic pH in vivo was deduced from measurements on blood drained from cat spleen during contraction with the inflow occluded. The pH of blood in the red pulp is normally 7.20, but stasis or reduced flow through the pulp causes pH to fall toward 6.8. The splenic pulp contains blood of high hematocrit. To evaluate the role of buffering by the red cells themselves, intrasplenic p/ in red cell-free spleens was, therefore, estimated atering and leaving the spleen during red cell washout. At inflow pH less than 6.8 the outflow pH was raised, at inflow pH = 6.8 there was no change, b,t at inflow pH greater than 6.8 the outflow pH was lowered. These results indicate that the pH environment of red cells in the spleen results indicate that the pH environment of red cells in the spleen results from the interplay of two separate factors: i) pH-determining elements of the splenic tissue that buffer at 6.8, and ii) buffering provided by red cells passing through the pulp.

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