Kinetic study of Na+-K+ pump in erythrocytes from essential hypertensive patients

1987 ◽  
Vol 252 (1) ◽  
pp. H1-H6 ◽  
Author(s):  
J. Diez ◽  
P. Hannaert ◽  
R. P. Garay
Keyword(s):  
Kinetic Study ◽  
Normal Limit ◽  
Maximal Rate ◽  
Normal Range ◽  
Apparent Dissociation Constant ◽  
Transport Pathways ◽  
Hypertensive Patients ◽  
L Cells ◽  
Na Efflux ◽  
Cotransport System

The interaction of the Na+-K+ pump with internal Na+ was investigated in erythrocytes from 38 normotensive control subjects and 49 essential hypertensive patients. In six of the hypertensive patients, the Na+-K+ pump exhibited an apparent dissociation constant for internal Na+ (KNa) above an upper normal limit of 7 mmol/l cells. Four of these six hypertensives showed an increase in the maximal rate of ouabain-sensitive Na+ efflux (Vmax), above an upper normal limit of 11 mmol X l cells-1 X h-1. These abnormalities were stable in repeated determinations over 1–3 yr. A kinetic study of other erythrocyte Na+ transport pathways showed that 16 hypertensives had a low apparent affinity of the Na+-K+ cotransport system for internal Na+, 10 hypertensives exhibited increased Na+-Li+ countertransport fluxes, and 11 hypertensives had increased Na+ leak. None of these three abnormalities were observed in the six hypertensives with abnormal pump fluxes. We thus propose to denominate them as Pump (-) hypertensives. Interestingly, four Pump (-) hypertensives exhibited an increased maximal rate of outward Na+-K+ cotransport. Basal erythrocyte Na+ content of Pump (-) hypertensives was within normal range. This suggests that the increased maximal rates of the Na+-K+ pump and Na+-K+ cotransport system compensate the low pump affinity for internal Na+.

Asymmetry of Na-K-Cl cotransport in human erythrocytes

1988 ◽  
Vol 254 (2) ◽  
pp. C243-C250 ◽  
Author(s):  
G. R. Kracke ◽  
M. A. Anatra ◽  
P. B. Dunham
Keyword(s):  
Human Erythrocytes ◽  
Red Cells ◽  
Mutual Dependence ◽  
L Cells ◽  
Na Efflux ◽  
Cotransport System ◽  
Human Red Cells

The Na-K-Cl cotransport system in human erythrocytes was studied by measuring net influxes and effluxes of Na and K. The influx of K was shown to be stimulated by Na and the influx of Na was stimulated by K, satisfying the fundamental criterion of cotransport. In addition, these mutually stimulating cation influxes had a stoichiometry of 1:1 and were entirely inhibited by furosemide; these results are also consistent with cotransport. Furthermore, the mutually stimulating influxes were entirely dependent on Cl, since they were abolished when nitrate was substituted for Cl. In contrast, cotransport, defined by mutual dependence of fluxes, was not detected in the outward direction over a range of cellular Na and K concentrations from 0 to 50 mmol/l cells. The cotransport pathway did, however, appear to mediate a Na-stimulated K efflux (but no K-stimulated Na efflux), and furosemide-inhibitable effluxes of both Na and K. Nitrate (but not sulfate) appeared to substitute for chloride in promoting Na-stimulated K efflux. Thus the Na-K-Cl cotransport system in human red cells is intrinsically asymmetric, and mediates coupled cation fluxes readily only in the inward direction.

Na+ leak in erythrocytes from essential hypertensive patients

1985 ◽  
Vol 69 (5) ◽  
pp. 613-624 ◽  
Author(s):  
Ricardo P. Garay ◽  
Corinne Nazaret
Keyword(s):  
Transport System ◽  
Rate Constant ◽  
Kinetic Properties ◽  
Maximal Rate ◽  
Hypertensive Patients ◽  
Apparent Affinity ◽  
Hypertensive Population ◽  
Number Of Patients ◽  
Sucrose Medium ◽  
Na Efflux

1. Ouabain- and bumetanide-resistant (OBR) Na+ efflux from human erythrocytes into a Mg2+-sucrose medium exhibits kinetic properties consistent with a transmembrane Na+ leak. 2. In 52 essential hypertensive patients, the rate constant of Na+ leak (ke) was 15.0 ± 2.9 × 10−3h−1 (mean ±sd). This was significantly higher than the ke in 47 normotensive controls (13.2 ± 1.6 × 10−3h−1; t = 3.81, P < 0.001; Mann-Whitney U rank sum test P = 0.0014). The relatively small number of patients studied was insufficient to decide if the hypertensive population was bi-modally distributed. Nevertheless, if the upper end of the normotensive population is used as a cutoff point, it appears that a subgroup of 12 hypertensive patients had an increased Na+ leak, ke = 19.5 ± 1.9 × 10−3 h−1 (mean±sd). The increased Na+ leak remained constant in repeated determinations over several months. 3. Na+ movements catalysed by the Na+-K+ co-transport and Na+-Li+ countertransport systems were measured in the above 52 hypertensive patients. Seventeen hypertensive patients showed a low apparent affinity of the co-transport system for internal Na+ and 12 exhibited a high maximal rate of Na+-Li+ countertransport. None of these two abnormalities was found in the 12 hypertensive patients with increased ke. We propose to denote them as Leak-(+) hypertensive patients. 4. Passive net Na+ entry was abnormally high in all Leak-(+) hypertensive patients. However, erythrocyte Na+ content was increased in only five of the 12 Leak-(+) hypertensive patients. A normal or even decreased Na+ content was associated with the presence of compensatory increases in the maximal rate of the Na+-K+ pump and the Na+-K+ co-transport system.

scholarly journals A kinetic analysis of Na-Li countertransport in human red blood cells.

1986 ◽  
Vol 87 (3) ◽  
pp. 353-368 ◽  
Author(s):  
P A Hannaert ◽  
R P Garay
Keyword(s):  
Red Blood Cells ◽  
Kinetic Analysis ◽  
Blood Cells ◽  
Kinetic Properties ◽  
Maximal Rate ◽  
Apparent Dissociation Constant ◽  
Human Red Blood Cells ◽  
Ping Pong ◽  
Na Efflux ◽  
Cation Sites

We examined the kinetic properties of the interactions between inner and outer cation sites of the Na-Li countertransport system in human red blood cells. Li-stimulated Na efflux [V(Na)] was measured as a function of external Li [(Li)o] and internal Na [(Na)i] contents. At each (Li)o, a Hanes plot of (Na)i/V(Na) vs. (Na)i allowed us to calculate the apparent dissociation constant for internal Na (KiNa) and the maximal rate of Na efflux [Vmax(Na)]. In erythrocytes from 10 different subjects, the Vmax(Na)/KiNa ratios were independent of the external Li concentrations. In other experiments, Na-stimulated Li efflux [V(Li)] was measured as a function of external Na and internal Li contents. In three subjects studied, the Vmax(Li)/KiLi ratios were independent of the external Na concentrations. The data strongly suggest that the countertransport mechanism is consecutive ("ping-pong").

Circulating Catecholamines and Systolic Time Intervals in Labile and Sustained Hypertension

1978 ◽  
Vol 55 (s4) ◽  
pp. 65s-68s ◽  
Author(s):  
D. Cousineau ◽  
J. de Champlain ◽  
L. Lapointe
Keyword(s):  
Heart Rate ◽  
Essential Hypertension ◽  
Myocardial Contractility ◽  
Systolic Time Intervals ◽  
Normal Range ◽  
Time Intervals ◽  
Hypertensive Patients ◽  
Sustained Hypertension ◽  
Systolic Time ◽  
Hypotensive Response

1. Average supine circulating total catecholamine concentrations were found to be higher than the normal range in about 50% of patients with labile hypertension and in about 30% of patients with sustained essential hypertension. 2. These higher resting concentrations were mainly due to an increase in adrenaline in labile hypertension and to an increase in noradrenaline in sustained hypertension. 3. Patients with elevated catecholamine concentrations were also characterized by a higher heart rate, by an increased myocardial contractility and by greater hypotensive response after treatment with β-adrenoreceptor blocking agents. 4. These studies suggest the existence of subgroups of hypertensive patients with increased sympathetic tone.

scholarly journals Profil Darah Ikan Gelodok (Periophthalmodon schlosseri) dan (Boleophthalamus boddarti) di Desa Kuala Tambangan Pelaihari, Kalimantan Selatan

2020 ◽  
Vol 7 (2) ◽  
pp. 176
Author(s):  
Nita Azhari ◽  
Hidayaturrahmah Hidayaturrahmah
Keyword(s):  
Normal Limit ◽  
Hemoglobin Concentration ◽  
Mangrove Ecosystem ◽  
Normal Range ◽  
Blood Profile ◽  
Normal Limits ◽  
Range Type ◽  
Periophthalmodon Schlosseri ◽  
The Village ◽  
Mean Cell Hemoglobin

Profil darah memiliki peran yang sangat penting dalam fisiologi metabolisme dan aktifitas tubuh hewan. Kuala Tambangan memiliki banyak potensi sumber daya ikan salah satunya ikan gelodok. Ikan gelodok di kawasan ini mudah ditemukan, akan tetapi sampai sekarang belum dimanfaatkan dengan baik oleh masyarakat. Tujuan penelitian ini untuk mengetahui profil darah ikan gelodok jenis Periophthalmodon schlosseri dan Boleophthalamus boddarti pada ekosistem mangrove yang berada di desa Kuala Tambangan, Kabupaten Tanah Laut, Kalimantan Selatan. Metode yang digunakan pada penelitian ini yaitu metode penangkapan hewan langka yaitu line transek, metode hemositometer dan metode sahli parameter yang dihitung hemoglobin, eritrosit, leukosit, hematokrit, MCV (Mean Corpusculla Volume), MCH (Mean Cell Hemoglobin), MCHC (Mean Cell Hemoglobin Concentration) pada 2 jenis ikan gelodok 34 ekor P. schlosseri dan 34 ekor B. boddarti. Hasil yang didapatkan adalah eritrosit P. schlosseri 3,87±0,58 x 106 sel/μL; B. boddarti 3,78±0,73 x 106 sel/μL 2 jenis ikan gelodok ini memiliki nilai eritrosit diatas batas normal; leukosit P. schlosseri 11,91±5,61 x103 sel/μL dan B. boddartii 9,72±4,24 x103 sel/μL nilai leukosit pada 2 jenis ikan gelodok ini berada di atas batas normal; hemoglobin P. schlosseri 11,59±1,75 % dan B. boddartii 11,75±1,96 % dari hasil yang didapat kadar hemoglobin pada 2 jenis ikan gelodok ini berada di atas batas normal kadar hemoglobin ikan pada umumnya; hematokrit P. schlosseri 34,32±5,57 % dan B. boddartii 35,71±5,44 % hasil hematokrit yang didapat dari 2 jenis ikan gelodok ini yaitu di atas batas normal; jenis P. schlosseri memiliki nilai MCV 88,72±6,62 μm3 yang berada di bawah batas normal; MCH 29,92±0,69 pg/sel yang berada di bawah batas normal; MCHC 33,99±3,97 g/dL pada jenis ini nilai MCHC masih berada pada batas normal; jenis B. boddartii memiliki nilai MCV 96,16±17,96 μm3 yang berada di bawah batas normal; MCH 31,51±5,50 pg/sel yang masih berada di batas normal; MCHC 32,87±1,77 g/dL nilai MCHC pada jenis ini masih berada pada batas normal. Blood profile has a very important role in the physiology of metabolism and animal body activities. Kuala Tambangan has a lot of potential fish resources, one of which is the fish Mudskipper. Mudskipper fish in this area are easy to find, but until now it has not been utilized properly by the community. The purpose of this study was to determine the blood profile of the Periophthalmodon Schlosseri and Boleophthalamus boddarti fish species in the mangrove ecosystem in the village of Kuala Tambangan, Tanah Laut District, South Kalimantan . The method used in this study is the method of catching endangered animals namely trasnek line, hemocytometer method and parameter Sahli method which is calculated hemoglobin, erythrocytes, leukocytes, hematocrit, MCV (Mean Corpuscular Volume), MCH (Mean Cell Hemoglobin), MCHC (Mean Cell Hemoglobin Concentration) on 2 types of fish, 34 Periophthalmodon schlosseri and 34 Boleophthalmus boddarti. The results obtained were P. schlosseri erythrocytes 3.87 ± 0.58 x 106 cells / μL; B. boddarti 3.78 ± 0.73 x 106 cells / μL 2 types of fish Mudskipper has erythrocyte values above the normal limit; P. schlosseri leukocytes 11.91 ± 5.61 x103 cells / μL and B. boddartii 9.72 ± 4.24 x103 cells / μL leukocyte values in these 2 types of jagged fish are above normal limits; hemoglobin P. schlosseri 11.59 ± 1.75 % and B. boddartii 11.75 ± 1.96 % from the results obtained by the hemoglobin levels in these 2 types of fishes are above the normal limit of fish hemoglobin levels in general; hematocrit P.schlosseri 34.32 ± 5.57 % and B. boddartii 35.71 ± 5.44 % hematocrit results obtained from these 2 types of mudskipper fish are above normal limits; P.schlosseri species had MCV values of 88.72 ± 6.62 μm3 which were below normal limits; MCH 29.92 ± 0.69 pg / cell that is below the normal range; MCHC 33.99 ± 3.97 g / dL in this type the MCHC value is still in the normal range; type B. boddartii has a MCV value of 96.16 ± 17.96 μm3 which is below normal limits; MCH 31,51 ± 5.50 pg / cell which is still in the normal range; MCHC 32.87 ± 1.77 g / dL MCHC values in this type are still within normal limits.Keywords: gelodok, blood, kuala tambangan

Sensitive fluorometry of heat-stable alkaline phosphatase (Regan enzyme) activity in serum from smokers and nonsmokers.

1983 ◽  
Vol 29 (2) ◽  
pp. 260-263 ◽  
Author(s):  
W C Maslow ◽  
H A Muensch ◽  
F Azama ◽  
A S Schneider
Keyword(s):  
Alkaline Phosphatase ◽  
Normal Limit ◽  
Heat Stability ◽  
Cross Reactivity ◽  
Fluorogenic Substrate ◽  
Normal Range ◽  
Heat Stable ◽  
Normal Individuals ◽  
Naphthoic Acid ◽  
The Mean

Abstract We developed a simple, sensitive enzymatic assay involving the fluorogenic substrate naphthol AS-MX phosphate [(3-hydroxy-2-naphthoic acid 2,4-dimethylanilide) phosphate] to measure heat-stable alkaline phosphatase (EC 3.1.3.1), the Regan isoenzyme, in human serum. The day-to-day CV was 5.7% for a serum activity of 0.080 arbitrary units/L. Measurable amounts of enzyme were detected in most normal individuals. The mean for 51 nonsmokers was 0.068 (SD 0.037) arb. units/L; for 25 smokers it was 0.440 (SD 0.360) arb. units/L. Activity of this isoenzyme in smokers was as much as 10-fold the upper normal limit for nonsmokers. Activation of this tumor marker by smoking has not received attention hitherto. We conclude that a truly normal range can only be established among nonsmokers. The isoenzymes in smokers, nonsmokers, and pregnant women were similar in their heat stability, immunologic cross reactivity, and inhibition by L-phenylalanine.

Permanent Hypertension after Renal Homotransplantation in Man

1975 ◽  
Vol 48 (5) ◽  
pp. 391-403 ◽  
Author(s):  
J. P. Grünfeld ◽  
D. Kleinknecht ◽  
J. F. Moreau ◽  
P. Kamoun ◽  
J. Sabto ◽  
...  
Keyword(s):  
Experimental Data ◽  
Blood Flow ◽  
Left Kidney ◽  
Plasma Renin ◽  
Artery Stenosis ◽  
Renin Release ◽  
Normal Range ◽  
Hypertensive Patients ◽  
The Mean ◽  
Arteriovenous Difference

1. In forty-one patients who underwent renal homotransplantation the following measurements were made: (a) blood flow and its distribution in the transplanted kidney as measured by the 85Kr washout method; (b) renin release in the renal vein of the transplant; (c) arteriovenous difference in plasma renin activity (PRA) of the recipient's remaining left kidney. 2. Eleven transplanted patients were normotensive. Renal haemodynamic data were comparable with those obtained in potential kidney donors. 3. Three hypertensive patients had chronic rejection. The mean renal blood flow and the percentage of flow in the first component of the washout curve were reduced. Renin release from the transplant, however, was normal. 4. Ten hypertensive patients had transplant artery stenosis. In eight of them renin release from the graft as well as peripheral PRA were within normal range. This result is similar to experimental data obtained in Goldblatt renovascular hypertension. The two patients with the tightest artery stenosis had an elevated renin release from the transplant. 5. Thirteen hypertensive patients had elevated arteriovenous difference in PRA of the recipient's own left kidney. Peripheral PRA was significantly higher than in normotensive patients. Left nephrectomy relieved hypertension in ten of them; three have not so far undergone nephrectomy. 6. In four other cases hypertension was also relieved by removal of the patient's own kidney; however, the arteriovenous difference in PRA of that kidney fell within normal range.

Insulin enhances sodium sensitivity of Na-K-ATPase in isolated rat proximal convoluted tubule

1994 ◽  
Vol 267 (1) ◽  
pp. F55-F62 ◽  
Author(s):  
E. Feraille ◽  
M. L. Carranza ◽  
M. Rousselot ◽  
H. Favre
Keyword(s):  
Dissociation Constant ◽  
Maximal Activity ◽  
Hydrolytic Activity ◽  
Proximal Convoluted Tubule ◽  
Maximal Rate ◽  
Apparent Dissociation Constant ◽  
Sodium Sensitivity ◽  
Rate Limiting ◽  
86Rb Influx ◽  
Isolated Rat

Insulin has been shown to stimulate the rate of ouabain-sensitive 86Rb influx in the isolated rat proximal convoluted tubule (PCT). To study the mechanism of this activation of Na-K-adenosinetriphosphatase (Na-K-ATPase), we determined the actions of insulin on 1) the maximal activity (Vmax) of Na-K-ATPase hydrolytic activity; 2) the maximal rate of ouabain-sensitive 86Rb influx (after intracellular Na loading); 3) the rate of ouabain-sensitive 86Rb influx under conditions where intracellular Na concentration is rate limiting, either in the presence or in the absence of 5 x 10(-4) M amiloride and/or low extracellular Na concentration (3 mM); and 4) the Na sensitivity of the Na-K-ATPase hydrolytic activity. The maximal rates of Na-K-ATPase hydrolytic activity and of ouabain-sensitive 86Rb uptake were unchanged by insulin. In contrast, we confirmed that insulin enhanced 86Rb uptake (in peq.mm-1.min-1) in the absence of inhibitor of the Na/H exchanger [18.2 +/- 1.7 to 24.1 +/- 1.3 (SE), P < 0.03] and, in addition, demonstrated a similar stimulation in the presence of either 5 x 10(-4) M amiloride (7.2 +/- 0.6 to 10.7 +/- 0.9, P < 0.01), 3 mM extracellular Na (4.1 +/- 0.4 to 5.6 +/- 0.2, P < 0.05), and both amiloride and 3 mM extracellular Na (2.1 +/- 0.7 to 4.5 +/- 0.4, P < 0.03). Finally, insulin increased the sensitivity of Na-K-ATPase to Na as the apparent dissociation constant decreased from 46.5 +/- 5.3 to 27.6 +/- 3.0 mM (P < 0.03).(ABSTRACT TRUNCATED AT 250 WORDS)

Betaine transport in rabbit renal brush-border membrane vesicles

1993 ◽  
Vol 264 (6) ◽  
pp. F948-F955 ◽  
Author(s):  
T. M. Wunz ◽  
S. H. Wright
Keyword(s):  
Brush Border ◽  
Brush Border Membrane ◽  
Renal Cortex ◽  
Membrane Vesicles ◽  
Brush Border Membrane Vesicles ◽  
Maximal Rate ◽  
Transport Pathways ◽  
Organic Osmolyte ◽  
Renal Brush Border Membrane ◽  
Renal Brush Border

Transport of the organic osmolyte betaine was characterized in brush-border membrane vesicles (BBMV) isolated from rabbit renal cortex. Inwardly directed gradients of either Na+ or H+ supported concentrative uptake in a manner consistent with the presence of parallel Na(+)-betaine and H(+)-betaine cotransport processes. Concentrative uptake occurred in the presence of membrane potential alone, indicating that betaine transport is electrogenic. Accumulation of betaine was not dependent on chloride in the medium. Whereas L-proline inhibited both the H(+)- and Na(+)-sensitive components of betaine transport, glycine blocked the H(+)-sensitive pathway and had little effect on Na(+)-sensitive betaine transport. Both pathways were adequately described by Michaelis-Menten kinetics. Under Na(+)-gradient conditions (pH equilibrium), the maximal rate of total betaine transport (Jmax) = 50.8 +/- 13.3 nmol.mg-1.min-1 and the concentration of total betaine producing half-maximal uptake (Kt) = 4.1 +/- 0.5 mM. Under H(+)-gradient conditions (Na+ free), Jmax = 102.5 +/- 10.5 nmol.mg-1.min-1 and Kt = 2.8 +/- 0.3 mM. Imposition of both Na+ and H+ gradients increased Jmax (142 +/- 25.5 nmol.mg-1.min-1) to a level significantly greater than that noted in the presence of a Na+ gradient alone. We conclude that betaine transport in renal BBMV involves two distinct transport pathways that are differentiated on the basis of sensitivity to either Na+ or H+ and by their specificity to proline and glycine.

scholarly journals Lipid Disorders in Elderly Hypertensive Patients

2012 ◽  
Vol 2012 ◽  
pp. 1-3
Author(s):  
Blas Gil-Extremera
Keyword(s):  
Blood Pressure ◽  
Ldl Cholesterol ◽  
Hdl Cholesterol ◽  
Pharmacologic Treatment ◽  
Normal Range ◽  
Hypertensive Patients ◽  
Lipid Disorders ◽  
Clinical Challenge ◽  
Elderly Hypertensive ◽  
Elderly Hypertensive Patients

Lipid disorders are a common clinical challenge in the western countries. In patients with dyslipemia (total cholesterol > 200 mg/dl, HDL cholesterol < 35 mg/dl, LDL cholesterol > 130 mg/dl and triglycerides > 150 mg/dl) it is mandatory to normalize blood pressure (<130/80 mmHg) as well to reduce LDL-C values to normal levels by using drugs to inhibit of endogenous and exogenous cholesterol, to decrease triglycerides, and increases HDL-C up to normal range. It is also essential to maintain for this purpose suitable dietetic measures (reduction of unsatured fats and salt intakes—<2.5 g/daily) and without interruption, to support pharmacologic treatment in most of the patients.

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