ATPase Activity Of Erythrocyte Membranes Research Articles

Erythrocyte membrane ATPase activity in Sickle cell crisis

Background: Sickle cell disease is a genetic disease caused by a point mutation in the beta globin gene on chromosome 11 leading to the substitution of valine in place of glutamic acid in beta subunit of globin molecule. The vaso-occlusive crisis, or sickle cell crisis, is a common painful complication of sickle cell disease in adolescents and adults. Many studies have suggested the alteration in intracellular concentration of various ions associated with sickle cell disease.Aims and Objectives: This study aims to evaluate the activity of red blood cell membrane ATPase activity of sickle cell crisis patients in comparison to sickle cell patients in steady state.Material and Methods: Twenty patients of sickle cell crisis were included in the study. Twenty sickle cell patients in steady state were also registered who served as controls. The RBC Membrane ATPase activity were estimated and expressed as μmol of Pi/μg of protein/hour.Results: The activity of membrane ATPase were found to be significantly high in patients of sickle cell crisis in comparison to steady state ones.Conclusion: Membrane ATPases play a crucial role in the pathophysiology of sickle cell crisis. This study can be a based upon for future studies to understand the pathophysiology of sickle cell crisis and development of diagnostic and treatment modalities for the same.Asian Journal of Medical Sciences Vol.8(5) 2017 27-30

The action of androgens on Na+,K+-ATPase activity of erythrocyte membranes

The effect of androgens (testosterone, androsterone, dehydroepiandrosterone and dehydroepiandrosterone sulfate) on erythrocyte membrane during their nonspecific binding was investigated. The change in erythrocyte membrane Na+,K+-ATPase activity was measured at different hormone concentration in a suspension. It is shown that the dependence has dome-shaped character: at the elevated hormone concentration Na+,K+-ATPase activity starts to increase, reaches its maximum, and then decreases. The hypothesis is put forward that an increase in microscopists of erythrocyte membrane first intensifies Na+,K+-ATPase activity due to the growth of the maximum energy of membrane phonons, and then decreases it due to hindering conformational transitions in the enzyme molecule.

Lipid composition and Na+,K+-ATPase activity in erythrocyte membranes of patients with type 2 diabetes mellitusand dyslipoproteinemia

Aim. To study lipid composition and Na+,K+-Na+,K+-ATPase activity in erythrocyte membranes of patients with type 2 diabetes mellitus and dyslipoproteinemia. Materials and methods. The study included 40 patients (22 men and 18 women) aged 40-65 years with DM2. Results. The patients had abnormal lipid composition and impaired Na+,K+-Na+,K+-ATPase activity in erythrocyte membranes. The magnitude of thesechanges depended on the duration of pathology, severity of diabetic dyslipoproteinemia, and quality of compensation of carbohydrate metabolism. Conclusion. Aim. Investigation of lipid dysorganization in erythrocyte membranes in patients with type 2 diabetes mellitus yields data for the developmentof therapeutic modalities to correct dyslipoproteinemia.

Reversal of ionoregulatory disruptions in occupational lead exposure by vitamin C

In order to investigate the toxic effects of lead during occupational exposure to this metal and the antidotal efficacy of ascorbic acid directed against these toxic effects, various artisans in Abeokuta, Nigeria, who have been shown to be occupationally exposed to lead were supplemented daily with 500 mg ascorbic acid for 2 weeks. Ca 2+-Mg 2+-ATPase activity in erythrocyte membrane, as well as calcium and magnesium concentrations in plasma, erythrocytes, erythrocyte membrane and urine of the artisans were determined before and after ascorbic acid supplementation. The 2-week ascorbic acid administration resulted in the reversal of lead-induced accumulation of calcium and magnesium in the erythrocyte membranes of the artisans. Ascorbic acid also reversed lead-induced inhibition of erythrocyte membrane Ca 2+-Mg 2+-ATPase. Urinary excretion of calcium and magnesium was not affected by ascorbic acid. There may be some scope in introducing ascorbic acid as an intervention strategy for the prevention and therapy of lead intoxication, especially in cases where the subjects cannot be removed from the source of lead exposure.

Plasma membrane calcium pump activity is affected by the membrane protein concentration: Evidence for the involvement of the actin cytoskeleton

Plasma membrane calcium pumps (PMCAs) are integral membrane proteins that actively expel Ca 2+ from the cell. Specific Ca 2+-ATPase activity of erythrocyte membranes increased steeply up to 1.5–5 times when the membrane protein concentration decreased from 50 μg/ml to 1 μg/ml. The activation by dilution was also observed for ATP-dependent Ca 2+ uptake into vesicles from Sf9 cells over-expressing the PMCA 4b isoform, confirming that it is a property of the PMCA. Dilution of the protein did not modify the activation by ATP, Ca 2+ or Ca 2+-calmodulin. Treatment with non-ionic detergents did not abolish the dilution effect, suggesting that it was not due to resealing of the membrane vesicles. Pre-incubation of erythrocyte membranes with Cytochalasin D under conditions that promote actin polymerization abolished the dilution effect. Highly-purified, micellar PMCA showed no dilution effect and was not affected by Cytochalasin D. Taken together, these results suggest that the concentration-dependent behavior of the PMCA activity was due to interactions with cytoskeletal proteins. The dilution effect was also observed with different PMCA isoforms, indicating that this is a general phenomenon for all PMCAs.

Nickel and Cadmium Concentrations in Plasma and Na+/K+ATPase Activities in Erythrocyte Membranes of the People Exposed to Cement Dust Emissions

The aim of this study was to determine the concentrations of nickel and cadmium in blood plasma of the people exposed to cement dust emissions and to investigate the effects of exposure period on the activities of Na+/K+ ATPase enzymes in their erythrocyte membranes. The study was carried out on people living in Eskişehir Cukurhisar rural area, located near a cement factory. Blood samples of the individuals residing in this area were taken from 80 subjects (30 for control) following a physical examination. The analysis of plasma samples showed that nickel concentrations in subject group were found to be significantly higher than those of the control group (p < 0.001). Cadmium concentrations were found to be within the reference values for both group and no difference was found between the subjects and controls (p > 0.05). Furthermore, no correlation was observed between the levels of Na+/K+ ATPase activity in erythrocyte membranes of the subject group and the ages of people living in the region (p > 0.05, r = 0.133). It was also observed that nickel concentrations increased by age (p < 0.001, r = 0.646) while no effect was observed in means of cadmium. Na+/K+ ATPase activities in the erythrocyte membranes were not affected. In conclusion although there was no difference between the Na+/K+ ATPase activity in means of age, there was an environmental pollution and may be it was due to the industrial plant.

Could monoamine plasma levels and erythrocyte membrane ATPase activities at birth be predictive for future hand performance?

The monoamine and intracellular calcium systems are two major elements of nervous system functions. However, their role in human brain development is unclear. We studied the association between activity of monoamine and intracellular calcium systems during prenatal life and subsequent psychomotor performances in healthy children. We used prospective data from 247 children followed from birth through 6 y of age. Among those, 195 were examined at 9 mo using the Brunet-Lézine Scales, whereas 126 were examined at 3 y and 100 at 6 y using the McCarthy Scales of Children's Ability. A blood sample was collected from the umbilical cord to measure levels of dopamine and serotonin metabolites (homovanillic acid and 5-hydroxyindoleacetic acid, respectively) and ATPase activities (Na+K+-ATPase and Ca2+Mg2+-ATPase). The hand skill score at 6 y of age was significantly and negatively correlated with ATPase activities and with monoamine metabolite concentrations. No other cognitive score was related to biochemical measures at birth. Results were adjusted for child's sex, mother's educational level, duration of labor, and tea consumption. Composite scores of ATPase activities and monoamine metabolite concentrations measured at birth explained 29% of hand skill score variance at 6 y. Our results demonstrate the importance of prenatal factors on monoaminergic and ATPase activities in early human psychomotor development. This study also suggests that specific psychometric measures such as fine motor tests may be a better developmental measurement to correlate with biochemical factors than general cognitive scales.

Hypochlorous acid inhibits glutathione S-conjugate export from human erythrocytes

It was found that the hypochlorous acid (HOCl) inhibits the active efflux of glutathione S-conjugates, 2,4-dinitrophenyl- S-glutathione (DNP-SG, c 50%=258±24 μM HOCl) and bimane- S-glutathione (B-SG, c 50%=125±16 μM HOCl) from human erythrocytes, oxidises intracellular reduced glutathione (the ratio [HOCl]/[GSH] oxidized=4) and inhibits basal as well as 2,4-dinitrophenol- (DNP) and 2,4-dinitrophenyl- S-glutathione (DNP-SG)-stimulated Mg 2+-ATPase activities of erythrocyte membranes. Multidrug resistance-associated protein (MRP1) mediates the active export of glutathione S-conjugates in mammalian cells, including human erythrocytes. A direct impairment of erythrocyte membrane MRP by hypochlorous acid was shown by electrophoresis and immunoblotting ( c 50%=478±36 μM HOCl). The stoichiometry of the MRP/HOCl reaction was 1:1. These results demonstrate that MRP can be one of the cellular targets for the inflammatory mediator hypochlorous acid.

Effect of Red Laser Light on Na+,K+-ATPase Activity in Human Erythrocyte Membranes Sensitized with Zn-Phthalocyanine

The influence of laser light (670 nm) on human erythrocyte membrane Na+,K(+)-ATPase activity in the presence and absence of Zn-phthalocyanine (ZnPc) was studied. The response of erythrocyte membranes to low-power laser irradiation has not been fully elucidated. In our study, we focused on the studies on photo-induced changes of Na+,K(+)-ATPase activity. The erythrocyte membrane suspensions were incubated with 2 mM of ZnPc and next irradiated with energy doses of 19.1, 38.2, 57.3, 76.4, and 95.5 J x cm(-2). The activity of Na+,K(+)-ATPase was assayed colorimetrically at the wavelength of 820 nm and expressed in micromol of inorganic phosphate released from ATP per mg of protein. The measurements of Na+,K(+)-ATPase activity in erythrocyte membranes incubated with ZnPc in the dark demonstrated that all concentrations of the dye (0.5, 1, 2, and 3 microM) stimulated enzyme activity. The concentration of 2 microM caused the smallest increase of enzyme activity, so this concentration was accepted for further studies. Irradiation of erythrocyte membranes in the presence of the dye (2 microM) significantly decreased Na+,K(+)-ATPase activity. Only for energy doses of 19.1 and 38.2 J x cm(-2) was the enzyme activity comparable to the activity of the control. It was found that irradiation with all energy doses applied caused a rise of enzyme activity. In the presence of ZnPc, significant decrease of Na+,K(+)-ATPase activity was observed.

Ca2+Mg3+‐ATPase activity in erythrocyte membranes in hypercalciuric nephrolithiasic patients

SUMMARY: Ca2+Mg2+ATPase is an enzyme involved in calcium transport across biological membranes. In order to determine its possible role in the pathogenesis of calcium nephrolithiasis, we assessed Ca2+Mg2+‐ATPase activity in erythrocyte membranes from 18 hypercalciuric (HC) nephrolithiasic patients (nine with absorptive hypercalciuria (AHC), nine with renal hypercalciuria (RHC)) and eight normocalciuric healthy controls (C). Participants took no medication for at least 3 months before the study and remained on a diet containing approximately 25 mmol of calcium per day for 14 days. Pump activity was measured in calmodulin‐free red blood cell membranes and expressed in umol of phosphate released per mg of membrane protein per h. There were statistically significant differences in pump activity between groups (1.43±0.07; 1.93±0.1; 1.65±0.06; C, AHC, RHC, respectively, P &lt; 0.005 (three groups) and P &lt; 0.02 AHC versus RHC. Enzyme activity was positively correlated with 24‐h urinary calcium excretion (r = 0.64, P &lt; 0.01) in HC patients; no such relationship was found in C. In conclusion, erythrocyte membrane Ca2+Mg2+ATPase activity is increased in HC. Differences in enzyme activity between AHC and RHC may reflect different degrees of a single generalized epithelial calcium transport disturbance.

Erythrocyte Na +, K +-ATPase activity in patients with congestive heart failure

In order to determine if the Na +, K +-ATPase activity in erythrocyte membranes is altered in congestive heart failure, and to examine its clinical significance with respect to other clinical variables, erythrocyte Na +, K +-ATPase activity was measured in 51 patients with left ventricular ejection fractions <40% (coronary artery disease, n=26; dilated cardiomyopathy, n=25) and 24 control patients. Na +, K +-ATPase activity was lower in both coronary artery disease and dilated cardiomyopathy groups than control group even in the absence of digitalis use. There was a significant inverse correlation between Na +, K +-ATPase activity and plasma norepinephrine. The presence of non-sustained ventricular tachycardia was associated with a lower Na +, K +-ATPase activity in both groups with congestive heart failure without digitalis use than those without ventricular tachycardia. Plasma norepinephrine was higher in patients with non-sustained ventricular tachycardia than those without in the coronary artery disease group, but not in the dilated cardiomyopathy group. Na +, K +-ATPase activity may be helpful in predicting electrophysiologic instability in patients with heart failure.

Erythrocyte membrane ATPase activities in patients with chronic active hepatitis B and C virus infections

The aim of the present study was to obtain erythrocyte membrane fractions from patients with chronic active hepatitis caused by hepatitis B virus (HBV) and hepatitis C virus (HCV) infections. Na +,K + ATPase activities were significantly lower ( P<0.005) in HBV related chronic active hepatitis ( n=20, 0.134±0.073 μmol P/mg protein per h) and in HCV hepatitis ( n=11, 0.144±0.049 μmol P/mg protein per h) when compared to control group ( n=10, 0.219±0.055 μmol P/mg protein per h). Both types of chronic active hepatitis B and C have markedly altered erythrocyte membrane Na +,K + ATPase activities that can be indicative of hepatic cell damage in humans. Although HBV and HCV infections are based on diverse mechanisms of action on their effect in liver injury, they cause similar effects on membrane ATPase activities.

Changes in erythrocyte membrane ATPases and plasma lipid peroxides in upper abdominal surgery under intravenous procaine-balanced anesthesia.

AIM:To observe the changes in erythrocyte membrane ATPases and plasma lipid peroxides (LPO) patients with in abdominal surgery under intravenous procainebalanced anesthesia.METHODS:By determining the ATPase activities of erythrocyte membrane, effects of upper abdominal surgery under intravenous procaine-balanced anesthesia on the function of erythrocytes were observed in 15 patients undergoing cholecystectomy and gastrectomy (5 males and 10 females, aged 45.9 ± 10.20 years and weighed 60.60kg ± 11.93kg). All patients were free from severe renal,hepatic, pulmonary, cardiac, metabolic and endocrinological diseases and acute infection for at least 2 weeks before surgery. Patients receiving any drug known to affect carbohydrate metabolism prior to anesthesia were excluded from the study.RESULTS:Erythrocyte membrane Na(+), K(+)-ATPase, Mg(2+)-ATPase, Ca(2+), Mg(2+)-ATPase activities were not significantly changed 60min-90min after incision as compared with 30min before anesthesia, but were decreased markedly 10min and 24 hours after completion of operation (P < 0.01). Plasma lipid peroxides (LPO) were increased significantly 24 hours after surgery (P < 0.01) following an initially marked but transient reduction. Plasma LPO changes were not correlated with erythrocyte membrane ATPase activities, r =-0.0396, -0.0097 and 0.4383, respectively (P > 0.05).CONCLUSION:Abdominal surgical trauma under intravenous procaine-balanced anesthesia may be associated with the decreased ATPase activities of erythrocyte membrane and increased LPO in plasma.

Uncouplers of Mitochondrial Oxidative Phosphorylation Are Not Substrates of the Erythrocyte Glutathione-S-Conjugate Pump

Uncouplers of mitochondrial oxidative phosphorylation, dinitrophenol (DNP) and carbonyl cyanideptrifluoromethoxyphenylhydrazone (FCCP), were found to stimulate Mg2+-ATPase activity of human erythrocyte membranes in a manner competitive with respect to 2,4-dinitrophenyl-S-glutathione (DNP-SG) which suggested that these compounds may also be substrates of the glutathione-S-conjugate pump. We confirm that the stimulation of erythrocyte membrane ATPase activity by DNP and by another uncoupler, carbonyl cyanidem-chlorophenylhydrazone (CCCP), is competitive with respect to DNP-SG. However, we found no evidence for active transport of DNP and CCCP out of erythrocytes and demonstrate that they inhibit the low-affinity component of DNP-SG transport noncompetitively while stimulating the high-affinity DNP-SG transport (mediated by multidrug resistance-associated protein, MRP1). Implications of these findings may indicate the electrogenic nature of MRP1-mediated transport of glutathione-Sconjugates and stimulation of aminophospholipid translocase (flippase) rather than the glutathione-S-conjugate pump by the uncouplers.

Alterations of erythrocyte ATPase activity and oxygen consumption in patients with liver-blood deficiency syndrome.

To investigate the pathophysiology of erythrocyte energy metabolic changes of patients with the traditional Chinese Medicine (TCM) liver-blood deficiency syndrome (LBDS). Erythrocyte membrane ATPase activity and oxygen consumption rate (OCR) were determined in 66 patients with LBDS, including 35 patients with iron deficiency anemia and 31 patients with chronic aplastic anemia. Thirty healthy adults served as controls. ATPase activity and OCR were decreased in patients with LBDS. The decreased erythrocyte ATPase activity and OCR might cause the energy hypometabolism in LBDS patients.

Toxic properties of Beauveria pigments on erythrocyte membranes

The Beauveria pigments, tenellin, bassianin and oosporein, all inhibited total erythrocyte membrane ATPase activity in a dose-dependent manner by as much as 50% at 200 μg/ml. These pigments inhibited Ca 2+-ATPases to a greater extent than Na + K + - ATPase activity. The ATPase inhibitory activity for these pigments was not specific but was probably a consequence of membrane disruption, since pigments all caused alterations in erythrocyte morphology and promoted varying degrees of cell lysis.

Peroxynitrite inhibits glutathione S-conjugate transport

Peroxynitrite was demonstrated to inhibit the active efflux of glutathione S-conjugates (2,4-dinitrophenyl- S-glutathione and bimane- S-glutathione) from human erythrocytes and the erythrocyte membrane ATPase activity stimulated by glutathione S-conjugates. As the multidrug resistance-associated protein (MRP) is responsible for the transport of glutathione S-conjugates in mammalian cells, these results point to the possibility of the effect of peroxynitrite on the MRP function.

Effects of glucose on the activity of erythrocyte membrane Ca2+ATPase in subjects with normal and impaired glucose tolerance.

The effects of glucose on Ca2+ATPase activity of erythrocyte membranes were investigated under in vitro and in vivo conditions. Results of the study, in vitro, showed that Ca2+ATPase activity of erythrocyte membrane was decreased by increasing glucose concentrations (0-30 mM). When glucose-6-phosphate (0-100 mM) was used instead of glucose no significant change occurred in Ca2+ATPase activity. Tunicamycin (0.01 ng/ml) when added to the incubation media together with glucose prevented the decrease in Ca2+ATPase activity. The results of the studies in vivo showed that Ca2+ATPase activities of both male and female subjects with normal or impaired glucose tolerance were changed with time in a complex manner after an oral glucose loading. However, Ca2+ATPase activities of the subjects with impaired glucose tolerance were smaller than those of the corresponding normal controls even before glucose administration.

Regulation of Rabbit Erythrocyte Ca2+-Pump Sensitivity to Calmodulin in Experimental Hyperlipidemia

Intracellular free calcium activity is in part determined by a calmodulin-regulated plasma membrane Ca(2+)-pump. Since changes in Ca2+ permeability have been implicated in atherosclerotic plaque formation, we initiated a lipid hyperalimentation protocol during which we measured various erythrocyte calcium flux parameters and early atheroma development. Adolescent New Zealand White rabbits were fed a diet with 0.5% cholesterol and 2.5% lard over a 3-month period. Plasma cholesterol and triacylglycerols increased on average 18.7- and 13.9-fold respectively, while erythrocyte membrane cholesterol content decreased 18% and total phospholipids by 54%. After 3 months of lipid hyperalimentation, 22% of the aortic arch was covered with large, early-stage, raised atheroma. Basal and calmodulin-activated (Ca2+ + Mg2+)-ATPase activities in erythrocyte membranes increased by 31% and 123%, respectively at 2 months, with a concomitant increase in calmodulin affinity (Km) from 15.6 to 4.2 nM. These differences were transient on account of changes in the control animals which exhibited a slowly developing sensitivity to calmodulin during maturation. Basal Ca2+ transport and passive Ca2+ permeability increased about 7-fold during the hyperlipidemic phase. This suggests that overt hyperlipidemia, leading to atherosclerotic plaque development, alters plasma membrane Ca2+ regulatory mechanisms including passive Ca2+ permeability. The changes in enzymatic function, membrane composition, and Ca2+ permeability seen in this red cell model system may be a reflection of early changes in cells that are directly involved in the development of atherosclerotic plaques.

Altered lipid composition and differential changes in activities of membrane-bound enzymes of erythrocytes in hepatic cirrhosis

Lipid composition, fluidity, and Na +,K +—adenosine triphosphatase (ATPase), Mg 2+-ATPase, and acetylcholinesterase (AChE) activities of erythrocyte membranes were examined in comparison to plasma lipid composition and lecithin:cholesterol acyltransferase (LCAT) activities in 39 patients with hepatic cirrhosis due to viral hepatitis (Child-Pugh class A, n = 12; class B, n = 13; and class C, n = 14). Plasma LCAT activities decreased and the plasma free—cholesterol to phospholipid molar ratio ( C PL ) increased with progressive severity of hepatic cirrhosis. C PL and fluorescence polarization (inverse of fluidity) of erythrocyte membranes also increased with disease progression ( C PL : Child-Pugh A, 0.911 ± 0.010; B, 0.941 ± 0.011; C, 0.979 ± 0.028; and normal, 0.798 ± 0.010; fluorescence polarization: Child-Pugh A, 0.348 ± 0.002; B, 0.351 ± 0.002; C, 0.355 ± 0.002; and normal, 0.340 ± 0.002). There was a correlation between C PL and fluorescence polarization of erythrocyte membranes ( r = .629, P < .001). Na +,K +-ATPase activity of erythrocyte membranes did not differ between cirrhotic patients and normal subjects. On the other hand, Mg 2+-ATPase activity decreased in Child-Pugh C cirrhosis. AChE activity was decreased in Child-Pugh A cirrhosis, and decreased further in Child-Pugh B and C cirrhosis. AChE and Mg 2+-ATPase activities correlated inversely with fluorescence polarization ( r = −.652, P < .001 and r = −.381, P < .01, respectively). These results suggest that the free-cholesterol content of erythrocyte membranes increased in parallel with a decrease in plasma LCAT activity with progression of severity of hepatic cirrhosis, and that a resultant decrease in membrane fluidity affected Mg 2+-ATPase and AChE activities but not Na +,K +-ATPase activity. These membrane-bound enzyme activities may show different dependencies on membrane fluidity.