Training-dependent changes of red cell density and erythrocytic oxygen transport

Prolonged endurance training causes a decreased O2 affinity of Hb, which is due to an increase in erythrocyte 2,3-diphosphoglycerate (2,3-DPG) concentration. Possible mechanisms were studied in 20 males with varying degrees of fitness. Training status was tested by ergometry. Red cell density and O2 transport parameters were determined before this test. The O2 tension at 50% O2 saturation of Hb (P50) was higher in the more fit subjects (+1.3 mmHg) and the 2,3-DPG concentration was higher (+2.3 mumol/g Hb) in this group. The mean density was significantly lower in fit subjects (1.1002 g/ml) as compared with less fit subjects (1.1056 g/ml), indicating a lower mean age. Density distribution curves show that in the fit subjects more young erythrocytes were in blood and that the very old erythrocytes were missing. After correction for the differences in the density distribution, no differences in the P50 value and 2,3-DPG concentration between less fit and fit subjects were found. Therefore, the decreased Hb-O2 affinity after training can be explained by the presence of more young erythrocytes in the blood of trained subjects. The magnitude of this effect correlates with the training status.

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Determinants of Sickle Cell Density Distribution: A Study of Benin Twins.

Blood ◽

10.1182/blood.v108.11.1244.1244 ◽

2006 ◽

Vol 108 (11) ◽

pp. 1244-1244

Author(s):

Mary E. Fabry ◽

Anne C. Rybicki ◽

Sandra M. Suzuka ◽

M. Cherif Rahimy ◽

Rajagopal Krishnamoorthy ◽

...

Keyword(s):

Density Distribution ◽

Cell Density ◽

Sickle Cell ◽

Dna Analysis ◽

Complex Mixture ◽

Density Gradients ◽

Red Cell ◽

Alpha Thalassemia ◽

Gardos Channel ◽

One Year

Abstract Red cell density distribution affects both hemolysis and vaso-occlusion; however, currently recognized factors cannot account for all of the variation seen. We hypothesized that a range of genetically controlled factors contributes to red cell density distribution and hemolysis, which has recently received a great deal of attention from Gladwin et al for its role in sickle cell anemia (SCA) and its impact on NO metabolism. Our previous studies have demonstrated that although RBC density distribution varies significantly from patient to patient, the pattern for individual patients is stable in the absence of disease. Some genetically determined factors that affect red cell density distribution have been defined, such as alpha-thalassemia and % HbF (Fabry et al, Blood, 1982); however, neither of these factors completely predicts density distribution. The study of identical twins offers the unique opportunity to minimize some of the genetic variability between individuals that may not be relevant to RBC density while allowing the remaining differences to be detected. Because SCA patients from the US have a complex mixture of Caucasian, other ethnicities, and genes from all parts of Africa including all of the sickle haplotypes, we have chosen to recruit our population from Benin that has a single beta-globin haplotype, thus further minimizing differences arising from admixture from inside and outside of Africa. We have collected samples from six sets of monozygous twins from Benin and validated their monozygosity by DNA analysis. Of the 6 twin sets analyzed to date, 4 have alpha-thalassemia. We compared density gradients on two separate occasions, approximately one year apart, for these twins and found that density gradients for both members of all twin sets without medical complications (malaria, painful crisis) were indistinguishable. This is not true for pairs of randomly chosen individuals even after their % HbF and alpha-thalassemia status has been determined and matched. After elimination of WBCs, we were able to isolate sufficient RNA to obtain microarray data without amplification. We compared subjects with a low % dense cells vs a high % dense cells. In the combinations that were analyzed, we found a consistent pattern of up- and down-regulated genes. Down-regulated genes included the Gardos channel (KCNN4), K-Cl cotransporter (KCC1), NOS3, CAIV, and PKC. Up-regulated genes included ferritin heavy chain (probably in mitochondria that are present in reticulocytes) and 2,3-bisphosphomutase that was elevated in twins with higher MCHC (density). The latter is consistent with our previous observations and those of Poillon et al that DPG can affect polymer formation and RBC density. We conclude that the study of twins demonstrates that there is a strong genetic component in the control of sickle cell density distribution and that a better understanding of factors controlling density distribution may lead to new forms of treatment.

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Effects of NO-Donors on Thrombus Formation and Microcirculation in Cerebral Vessels of the Rat

Thrombosis and Haemostasis ◽

10.1055/s-0038-1650532 ◽

1996 ◽

Vol 76 (01) ◽

pp. 111-117 ◽

Cited By ~ 10

Author(s):

Yasuto Sasaki ◽

Junji Seki ◽

John C Giddings ◽

Junichiro Yamamoto

Keyword(s):

Blood Flow ◽

Thrombus Formation ◽

Dependent Manner ◽

Red Cell ◽

Cell Velocity ◽

Red Cell Velocity ◽

The Mean ◽

Wall Shear ◽

Dose Dependent

SummarySodium nitroprusside (SNP) and 3-morpholinosydnonimine (SIN-1), are known to liberate nitric oxide (NO). In this study the effects of SNP and SIN-1 on thrombus formation in rat cerebral arterioles and venules in vivo were assessed using a helium-neon (He-Ne) laser. SNP infused at doses from 10 Μg/kg/h significantly inhibited thrombus formation in a dose dependent manner. This inhibition of thrombus formation was suppressed by methylene blue. SIN-1 at a dose of 100 Μg/kg/h also demonstrated a significant antithrombotic effect. Moreover, treatment with SNP increased vessel diameter in a dose dependent manner and enhanced the mean red cell velocity measured with a fiber-optic laser-Doppler anemometer microscope (FLDAM). Blood flow, calculated from the mean red cell velocity and vessel diameters was increased significantly during infusion. In contrast, mean wall shear rates in the arterioles and venules were not changed by SNP infusion. The results indicated that SNP and SIN-1 possessed potent antithrombotic activities, whilst SNP increased cerebral blood flow without changing wall shear rate. The findings suggest that the NO released by SNP and SIN-1 may be beneficial for the treatment and protection of cerebral infarction

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Alzheimer’s Disease: Erythrocyte 2,3-diphosphoglycerate Content and Circulating Erythropoietin

Current Alzheimer Research ◽

10.2174/1567205016666190827120108 ◽

2019 ◽

Vol 16 (9) ◽

pp. 834-835

Author(s):

Petter Järemo ◽

Alenka Jejcic ◽

Vesna Jelic ◽

Tasmin Shahnaz ◽

Homira Behbahani ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Cognitive Impairment ◽

Cell Damage ◽

Control Group ◽

Red Cell ◽

Oxygen Release ◽

Regulatory Pathways ◽

Β Amyloid ◽

2,3 Dpg

Background: Alzheimer’s Disease (AD) features the accumulation of β-amyloid in erythrocytes. The subsequent red cell damage may well affect their oxygen-carrying capabilities. 2,3- diphosphoglycerate (2,3-DPG) binds to the hemoglobin thereby promoting oxygen release. It is theorized that 2,3-DPG is reduced in AD and that the resulting hypoxia triggers erythropoietin (EPO) release. Methods & Objective: To explore this theory, we analyzed red cell 2,3-DPG content and EPO in AD, mild cognitive impairment, and the control group, subjective cognitive impairment. Results: We studied (i) 2,3-DPG in red cells, and (ii) circulating EPO in AD, and both markers were unaffected by dementia. Disturbances of these oxygen-regulatory pathways do not appear to participate in brain hypoxia in AD.

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27-gauge trocar-assisted sutureless intraocular lens fixation

BMC Ophthalmology ◽

10.1186/s12886-020-01758-6 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Tatsuya Jujo ◽

Jiro Kogo ◽

Hiroki Sasaki ◽

Reio Sekine ◽

Keiji Sato ◽

...

Keyword(s):

Visual Acuity ◽

Endothelial Cell ◽

Cell Density ◽

Intraocular Lens ◽

Vitreous Hemorrhage ◽

Corneal Endothelial Cell ◽

Endothelial Cell Density ◽

Corneal Endothelial Cell Density ◽

The Mean ◽

Iol Fixation

Abstract Backgrounds However there have been numerous investigations of intrascleral intraocular lens (IOL) fixation techniques, there is room for improvement in terms of simplifying complicated techniques and reducing the high levels of skill required. This study aimed to report a novel technique for sutureless intrascleral fixation of the IOL using retinal forceps with a 27-gauge trocar. Methods Nineteen eyes of 18 patients underwent intrascleral fixation of the IOL from July 2018 to September 2019 were enrolled in this study. A 27-gauge trocar formed 3-mm scleral tunnels positioned at 4 and 10 o’clock, 2 mm from the corneal limbus. We used a 3-piece IOL haptic grasped by a 27-gauge retinal forceps and pulled from the 27-gauge trocar. The IOL was fixed by making a flange. Main outcome measures were visual acuity, corneal endothelial cell density, IOL tilt, decentration, predicted error of refraction and complications. Results The 19 eyes were followed up for 1 month. The mean pre- and postoperative logMAR uncorrected visual acuity (UCVA) was 1.06 ± 0.63 and 0.40 ± 0.26, respectively (p < 0.01), while the mean pre- and postoperative logMAR best corrected visual acuity (BCVA) was 0.27 ± 0.51 and 0.06 ± 0.15, respectively (p = 0.09). The mean corneal endothelial cell density was 2406 ± 625 to 2004 ± 759 cells/mm2 at 1 month (p = 0.13). The mean IOL tilt was 3.52 ± 3.00°, and the mean IOL decentration was 0.39 ± 0.39 mm. There was no correlation among IOL tilt, decentration and BCVA (p > 0.05). The mean prediction error of the target refraction was − 0.03 ± 0.93 D. The complications were vitreous hemorrhage (3 eyes), hyphema (1 eye), IOP elevation (1 eye), iris capture of the IOL (1 eye) and hypotony (2 eyes). No IOL dislocation occurred. Conclusions IOL intrascleral fixation with a flange achieved good IOL fixation and visual outcome in the scleral tunnels created with the 27-gauge trocar.

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The effect of 2,3-DPG on red cell phosphofructokinase

FEBS Letters ◽

10.1016/0014-5793(73)80417-x ◽

1973 ◽

Vol 37 (1) ◽

pp. 21-22 ◽

Cited By ~ 9

Author(s):

E. Beutler ◽

E. Guinto

Keyword(s):

Red Cell ◽

2,3 Dpg

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Effect of training status and exercise mode on endogenous steroid hormones in men

Journal of Applied Physiology ◽

10.1152/japplphysiol.00656.2003 ◽

2004 ◽

Vol 96 (2) ◽

pp. 531-539 ◽

Cited By ~ 141

Author(s):

Mark S. Tremblay ◽

Jennifer L. Copeland ◽

Walter Van Helder

Keyword(s):

Resistance Exercise ◽

Dehydroepiandrosterone Sulfate ◽

Exercise Session ◽

Total Testosterone ◽

Training Status ◽

Caloric Expenditure ◽

Trained Subjects ◽

Exercise Mode ◽

Response To Exercise ◽

Resistance Exercise Session

The purpose of this study was to determine the acute anabolic and catabolic hormone response to endurance and resistance exercise bouts of equal volume in subjects with differing training status. Twenty-two healthy men were recruited who were either resistance trained ( n = 7), endurance trained ( n = 8), or sedentary ( n = 7). Three sessions were completed: a resting session, a 40-min run at 50-55% maximal oxygen consumption, and a resistance exercise session. Expired gases were monitored continuously during exercise, and the endurance and resistance exercise sessions were individually matched for caloric expenditure. Blood samples were drawn before exercise and 1, 2, 3, and 4 h after the start of the exercise. Plasma was analyzed for luteinizing hormone, dehydroepiandrosterone sulfate, cortisol, and free and total testosterone. Androgens increased in response to exercise, particularly resistance exercise, whereas cortisol only increased after resistance exercise. Dehydroepiandrosterone sulfate levels increased during the resistance exercise session and remained elevated during recovery in the resistance-trained subjects. Endurance-trained subjects displayed less pronounced changes in hormone concentrations in response to exercise than resistance-trained subjects. After an initial postexercise increase, there was a significant decline in free and total testosterone during recovery from resistance exercise ( P < 0.05), particularly in resistance-trained subjects. On the basis of the results of this study, it appears that the endogenous hormone profile of men is more dependent on exercise mode or intensity than exercise volume as measured by caloric expenditure. The relatively catabolic environment observed during the resistance session may indicate an intensity-rather than a mode-dependent response.

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Red-cell 2,3-diphosphoglycerate in patients with hyperthyroidism

Acta Endocrinologica ◽

10.1530/acta.0.0930424 ◽

1980 ◽

Vol 93 (4) ◽

pp. 424-429 ◽

Cited By ~ 3

Author(s):

J. L. Alvarez-Sala ◽

M. A. Urbán ◽

J. J. Sicilia ◽

A. J. Diaz Fdez ◽

F. Fdez Mendieta ◽

...

Keyword(s):

Thyroid Hormones ◽

Control Group ◽

Red Cell ◽

Oxygen Dissociation Curve ◽

Dissociation Curve ◽

Oxygen Dissociation ◽

The Right ◽

Serum Thyroid Hormones ◽

Hyperthyroid Patients ◽

2,3 Dpg

Abstract. In 21 hyperthyroid female patients studied on 29 occasions, high levels of red-cell 2,3-diphosphoglycerate (2,3-DPG) have been found (5.75 ± 0.7 mm) which, compared to a euthyroid control group (4.88 ± 0.4 mm), could not be accounted for by differences in haematocrit, haemoglobin or phosphataemia. A significant correlation was found (P < 0.05) between serum thyroid hormones and the 2,3-DPG concentration in the hyperthyroid patients. Eight of these patients were reexamined after treatment and normalization of thyroid function, showed a regression to normal 2,3-DPG values (4.81 ± 0.6 mm) which could not be attributed to variations in haematocrit, haemoglobin or phosphataemia either. We therefore deduce that the shift to the right in the haemoglobin oxygen dissociation curve observed in patients of this type may be due to an increase in the red-cell 2,3-DPG content.

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Neonatal Polycythemia: II. Plasma, Blood, and Red Cell Volume Estimates in Relation to Hematocrit Levels and Quality of Intrauterine Growth

PEDIATRICS ◽

10.1542/peds.68.2.175 ◽

1981 ◽

Vol 68 (2) ◽

pp. 175-182

Author(s):

Yves W. Brans ◽

Donna L. Shannon ◽

Rajam S. Ramamurthy

Keyword(s):

Birth Weight ◽

Exchange Transfusion ◽

Intrauterine Growth Retardation ◽

Umbilical Vein ◽

Normal Growth ◽

Red Cell ◽

Intrauterine Growth ◽

The Mean ◽

Volume Estimates

Volumes of plasma (PV), blood (BV), and red cells (RCV) were estimated within 32 hours of birth in 39 neonates with normal growth, 14 neonates with intrauterine growth retardation, and 20 neonates with macrosomia. Total PV, BV, and RCV increased linearly with birth weight and were unaffected by deviation in the quality of fetal growth. In proportion to body weight, PV/kg, BV/kg, and RCV/kg correlated neither with birth weight nor with the quality of intrauterine growth. Neonates with umbilical vein hematocrit (UV Hct) levels 51% to 60%, 61% to 65%, and 66% to 77% had progressively lower, but not statistically different, mean PV/kg (38.1 ± 4.49, 37.6 ± 5.41, and 34.8 ± 5.16 ml/kg, respectively). On the other hand, they had progressively higher mean BV/kg (90 ± 10.1 vs 101 ± 13.7 ml/kg, P < .002, and vs 110 ± 19.0 ml/kg, P < .001). They also had progressively higher mean RCV/kg (52 ± 7.4, 64 ± 8.7, and 75 ± 16.4 ml/kg, P < .001). Although PV/kg did not correlate with UV Hct, both BV/kg and RCV/kg increased linearly with increasing UV Hct (r = .58 and r = .79, respectively). Volume estimates were repeated after partial exchange transfusion in 29 neonates. Mean UV Hct decreased from 63 ± 5.9% preexchange to 51 ± 5.2% postexchange (P < .001), mean PV increased from 37.7 ± 5.56 to 47.6 ± 7.99 ml/kg (P < .001) and mean RCV decreased from 67 ± 16.5 to 51 ± 12.3 ml/kg (P < .001). Despite precautions to keep the partial exchange isovolemic, mean BV decreased from 105 ± 18.7 to 98 ± 18.0 ml/kg (P = .001) and the mean PV increase (10 ml/kg) was less than the mean RCV decrease (16 ml/kg). These data suggest that neonates with polycythemia have normal PV but their RCV and BV are elevated in direct proportion to UV Hct. "Isovolemic" partial exchange transfusion decreases UV Hct, RCV, and BV and increases PV.

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Analysis of Red Cell Mass and Plasma Volume in Patients With Polycythemia

Archives of Pathology & Laboratory Medicine ◽

10.5858/2005-129-89-aorcma ◽

2005 ◽

Vol 129 (1) ◽

pp. 89-91 ◽

Cited By ~ 2

Author(s):

Mordechai Lorberboym ◽

Naomi Rahimi-Levene ◽

Helena Lipszyc ◽

Chun K. Kim

Keyword(s):

Body Weight ◽

Plasma Volume ◽

Cell Mass ◽

Mean Value ◽

Whole Body ◽

Red Cell ◽

Volume Data ◽

Red Cell Mass ◽

The Mean ◽

Iodine 125

Abstract Context.—Polycythemia describes an increased proportion of red blood cells in the peripheral blood. In absolute polycythemia, there is increased red cell mass (RCM) with normal plasma volume, in contrast with apparent polycythemia, in which there is increased or normal RCM and decreased plasma volume. In order to deliver the appropriate treatment it is necessary to differentiate between the two. Objective.—A retrospective analysis of RCM and plasma volume data are presented, with special attention to different methods of RCM interpretation. Design.—The measurements of RCM and plasma volume in 64 patients were compared with the venous and whole-body packed cell volume, and the incidence of absolute and apparent polycythemia was determined for increasing hematocrit levels. Measurements of RCM and plasma volume were performed using chromium 51–labeled red cells and iodine 125–labeled albumin, respectively. The measured RCM of each patient was expressed as a percentage of the mean expected RCM and was also defined as being within or outside the range of 2 SD of the mean. The results were also expressed in the traditional manner of mL/kg body weight. Results.—Twenty-one patients (13 women and 8 men) had absolute polycythemia. None of them had an increased plasma volume beyond 2 SD of the mean. When expressed according to the criteria of mL/kg body weight, 17 of the 21 patients had abnormally increased RCM, but 4 patients (19%) had a normal RCM value. Twenty-eight patients had apparent polycythemia. The remaining 15 patients had normal RCM and plasma volume. Conclusions.—The measurement of RCM and plasma volume is a simple and necessary procedure in the evaluation of polycythemia. In obese patients, the expression of RCM in mL/kg body weight lacks precision, considering that adipose tissue is hypovascular. The results of RCM are best described as being within or beyond 2 SD of the mean value.

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