共查询到20条相似文献,搜索用时 31 毫秒
1.
H. K. Kimelberg 《Journal of neurochemistry》1974,22(6):971-976
—The ouabain-sensitive K+ uptake and ATPase activities of cultured glioma and neuroblastoma cells were studied. Both cell lines showed ouabain-sensitive K+ uptake which correlated with the level of [Na++ K+]ATPase activity found in the respective total cell homogenate. The glioma cells had a 2.1-fold higher rate of K+ uptake than neuroblastoma cells, and a 2.4-fold higher [Na++ K+]ATPase activity. In the presence of ouabain neuroblastoma cells released K+ and took up Na+ in a 1:1 ratio. These results are compared and contrasted with similar studies on brain tissue and isolated cells. It is suggested that the cultured cell lines may serve as good models for the cation transport properties of their tissue counterparts. 相似文献
2.
P. Vague T. C. Coste M. F. Jannot D. Raccah M. Tsimaratos 《Experimental diabetes research》2004,5(1):37-50
Na+,K+-ATPase is an ubiquitous membrane enzyme
that allows the extrusion of three sodium ions from the cell
and two potassium ions from the extracellular fluid. Its activity
is decreased in many tissues of streptozotocin-induced
diabetic animals. This impairment could be at least partly
responsible for the development of diabetic complications.
Na+,K+-ATPase activity is decreased in the red blood cell
membranes of type 1 diabetic individuals, irrespective of the
degree of diabetic control. It is less impaired or even normal
in those of type 2 diabetic patients. The authors have
shown that in the red blood cells of type 2 diabetic patients,
Na+,K+-ATPase activity was strongly related to blood C-peptide
levels in non–insulin-treated patients (in whom C-peptide
concentration reflects that of insulin) as well as in
insulin-treated patients. Furthermore, a gene-environment
relationship has been observed. The alpha-1 isoform of the
enzyme predominant in red blood cells and nerve tissue is
encoded by the ATP1A1 gene.Apolymorphism in the intron
1 of this gene is associated with lower enzyme activity in patients
with C-peptide deficiency either with type 1 or type
2 diabetes, but not in normal individuals. There are several
lines of evidence for a low C-peptide level being responsible
for low Na+,K+-ATPase activity in the red blood cells.
Short-term C-peptide infusion to type 1 diabetic patients
restores normal Na+,K+-ATPase activity. Islet transplantation,
which restores endogenous C-peptide secretion, enhances
Na+,K+-ATPase activity proportionally to the rise
in C-peptide. This C-peptide effect is not indirect. In fact,
incubation of diabetic red blood cells with C-peptide at
physiological concentration leads to an increase of Na+,K+-ATPase activity. In isolated proximal tubules of rats or
in the medullary thick ascending limb of the kidney, C-peptide stimulates in a dose-dependent manner Na+,K+-ATPase activity. This impairment in Na+,K+-ATPase activity,
mainly secondary to the lack of C-peptide, plays probably
a role in the development of diabetic complications.
Arguments have been developed showing that the diabetesinduced
decrease in Na+,K+-ATPase activity compromises
microvascular blood flow by two mechanisms: by affecting
microvascular regulation and by decreasing red blood cell
deformability, which leads to an increase in blood viscosity.
C-peptide infusion restores red blood cell deformability
and microvascular blood flow concomitantly with Na+,K+-ATPase activity. The defect in ATPase is strongly related to
diabetic neuropathy. Patients with neuropathy have lower
ATPase activity than those without. The diabetes-induced
impairment in Na+,K+-ATPase activity is identical in red
blood cells and neural tissue. Red blood cell ATPase activity
is related to nerve conduction velocity in the peroneal
and the tibial nerve of diabetic patients. C-peptide infusion
to diabetic rats increases endoneural ATPase activity in rat.
Because the defect in Na+,K+-ATPase activity is also probably
involved in the development of diabetic nephropathy and
cardiomyopathy, physiological C-peptide infusion could be
beneficial for the prevention of diabetic complications. 相似文献
3.
Maximum ATPase activities in the cell wall fraction of English ryegrass (Lolium perenne L.) roots were stimulated by foru discrete millimole ratios of (Na++ K+); 40:0, 35:5, 5:35, and 0:40. The optimal pH for stimlation was found to be 6.5. Contrary to data in the literature, Mg2+ inhibited all stimulatory ratios of (Na++ K+) when plants were cultured on an adequate nutrient solution. When grown on a dilute solution, Mg2+ enhanced (Na++ K+)-stimulated ATPase activity in this membrane preparation. The single optimal combined concentration of (Na++ K+) for all stimulatory ratios was 40 MM. The ratios of (Na++ K+) which stimulated ATPase activity in the cell wall fraction varied with position along the root axis such that all rarely existed simultaneously nor did any exist in the terminal millimetre of the root. Both cell wall and microsomal fractions showed stimulation by (Na++ K+) at all the above ratios indicating the possible presence of plasma membrane fragments in both fractions. Only the 35:5 ratio was stimulations were found in the supernatant. Implications of ion-stimulated ATPase involvement in ion transport were drawn from the appearance of ATPase activity at a 40:0 ratio of (Na++ K+) and the disappearance of stimulations at 35:5, 5:35, and 0:40 ratios when plants were moved from a strong (35 mM total concentration) to a dilute (0.75 mM) nutrient solution. 相似文献
4.
Hideo Ochiai Hiroshi Eguchi Shunsuke Noguchi Yutaro Hayashi Hideaki Nishino Masaru Kawamura Chau H. Wu 《Journal of molecular recognition : JMR》2013,26(1):32-37
Glutathione S‐transferase (GST) was found to complex with the Na+,K+‐ATPase as shown by binding assay using quartz crystal microbalance. The complexation was obstructed by the addition of antiserum to the α‐subunit of the Na+,K+‐ATPase, suggesting the specificity of complexation between GST and the Na+,K+‐ATPase. Co‐immunoprecipitation experiments, using the anti‐α‐subunit antiserum to precipitate the GST‐Na+,K+‐ATPase complex and then using antibodies specific to an isoform of GST to identify the co‐precipitated proteins, revealed that GSTπ was complexed with the Na+,K+‐ATPase. GST stimulated the Na+,K+‐ATPase activity up to 1.4‐fold. The level of stimulation exhibited a saturable dose–response relationship with the amount of GST added, although the level of stimulation varied depending on the content of GSTπ in the lots of GST received from supplier. The stimulation was also obtained when recombinant GSTπ was used, confirming the results. When GST was treated with reduced glutathione, GST activity was greatly stimulated, whereas the level of stimulation of the Na+,K+‐ATPase activity was similar to that when untreated GST was added. When GST was treated with H2O2, GST activity was greatly diminished while the stimulation of the Na+,K+‐ATPase activity was preserved. The results suggest that GSTπ complexes with the Na+,K+‐ATPase and stimulates the latter independent of its GST activity. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
5.
Halide E. Temel Fahrettin Akyuz 《Journal of enzyme inhibition and medicinal chemistry》2013,28(2):213-217
Diabetes mellitus induces a decrease in sodium potassium-adenosine triphosphatase (Na+/K+- ATPase) activity in several tissues in the rat and red blood cells (RBC) and nervous tissue in human patients. This decrease in Na+/K+- ATPase activity is thought to play a role in the development of long term complications of the disease. Angiotensin enzyme inhibitors (ACEi) and angiotensin-II receptor antagonists (ARBs) reduce proteinuria and retard the progression of renal failure in patients with IDDM and diabetic rats. We investigated the effects of captopril and losartan, which are used in the treatment of diabetic nephropathy, on Na+/K+- ATPase activity. Captopril had an inhibitory effect on red cell plasma membrane Na+/K+ ATPase activity, but losartan did not. Our study draws attention to the inhibitory effect of captopril on Na+/K+ ATPase activity. Micro and macro vascular complications are preceeding mortality and morbidity causes in diabetes mellitus. There is a strong relationship between the decrease in Na+/K+ ATPase activity and hypertension. The non-sulphydryl containing ACEi and ARBs must be the choice of treatment in hypertensive diabetic patients and diabetic nephropathy. 相似文献
6.
Digitalis glycosides are potent polyclonal B cell activators in digitalis-resistant species. The stimulatory capacity is not mediated via their interaction with Na+, K+ ATPase (EC 3.6.1.3) but is due to binding to a distinct mitogen receptor located in the cell membrane. Potassium was found to influence the dose-response profile of digitalis-induced mitogenesis, thus suggesting a physiological relationship between the stimulating receptor on lymphoid cells and the Na+, K+ ATPase. 相似文献
7.
Beside functional and structural changes in vascular biology,
alterations in the rheologic properties of blood cells
mainly determines to an impaired microvascular blood
flow in patients suffering from diabetes mellitus. Recent
investigations provide increasing evidence that impaired
C-peptide secretion in type 1 diabetic patients might contribute
to the development of microvascular complications.
C-peptide has been shown to stimulate endothelial
NO secretion by activation of the Ca2+ calmodolin regulated
enzyme eNOS. NO himself has the potency to increase
cGMP levels in smooth muscle cells and to activate
Na+ K+ ATPase activity and therefore evolves numerous effects
in microvascular regulation. In type 1 diabetic patients,
supplementation of C-peptide was shown to improve endothelium
dependent vasodilatation in an NO-dependent
pathway in different vascular compartments. In addition,
it could be shown that C-peptide administration in type 1
diabetic patients, results in a redistribution of skin blood
flow by increasing nutritive capillary blood flow in favour
to subpapillary blood flow. Impaired Na+ K+ ATPase in another
feature of diabetes mellitus in many cell types and
is believed to be a pivotal regulator of various cell functions.
C-peptide supplementation has been shown to restore
Na+ K+ATPase activity in different cell types during
in vitro and in vivo investigations. In type 1 diabetic patients,
C-peptide supplementation was shown to increase
erythrocyte Na+ K+ATPase activity by about 100%. There
was found a linear relationship between plasma C-peptide
levels and erythrocyte Na+ K+ATPase activity. In small
capillaries, microvascular blood flow is increasingly determined
by the rheologic properties of erythrocytes. Using laser-diffractoscopie a huge improvement in erythrocyte deformability
could be observed after C-peptide administration
in erythrocytes of type 1 diabetic patients. Inhibition
of the Na+ K+ATPase by Obain completely abolished the
effect of C-peptide on erythrocyte deformability. In conclusion,
C-peptide improves microvascular function and blood
flow in type 1 diabetic patients by interfering with vascular
and rheological components of microvascular blood flow. 相似文献
8.
Robert S. Balaban John P. Bader 《Biochimica et Biophysica Acta (BBA)/Molecular Cell Research》1984,804(4):419-426
In several tissues a coupling between glycolysis and (Na++K+)-ATPase has been observed. We report here studies on the coupling of glycolysis and (Na++K+)-ATPase in Rous-transformed hamster cells and Ehrlich ascites tumor cells. The rate of (Na++K+)-ATPase was estimated by the initial rate of ouabain-sensitive K+ influx after K+ reintroduction to K+-depleted cells. Experiments were performed with cells producing ATP via oxidative phosphorylation alone (i.e., lactate sole substrate), glycolysis alone (i.e., glucose as substrate in the absence of oxygen or with antimycin A), or glycolysis and oxidative phosphorylation (i.e., glucose as substrate in the presence of oxygen). The cells produced ATP at approximately the same rate under all of these conditions, but the initial rate of K+-influx was approx. 2-fold higher when AtP was produced from glycolysis. Changes in cell Na+ due to other transport processes related to glycolysis, such as Na+-H+ exchange, Na+-glucose cotransport, and K+-H+ exchange were ruled out as mediators of this effect on (Na++K+)-ATPase. These data suggest that glycolysis is more effective than oxidative phosphorylation in providing ATP to (Na++K+)-ATPase to these cultured cells. 相似文献
9.
Enteropathogenic Escherichia coli (EPEC) uses a type III secretion system to inject effector proteins into host intestinal epithelial cells causing diarrhoea. EPEC infection redistributes basolateral proteins β1‐integrin and Na+/K+ ATPase to the apical membrane of host cells. The Crumbs (Crb) polarity complex (Crb3/Pals1/Patj) is essential for epithelial cell polarisation and tight junction (TJ) assembly. Here, we demonstrate that EPEC displaces Crb3 and Pals1 from the apical membrane to the cytoplasm of cultured intestinal epithelial cells and colonocytes of infected mice. In vitro studies show that EspF, but not Map, alters Crb3, whereas both effectors modulate Pals1. EspF perturbs polarity formation in cyst morphogenesis assays and induces endocytosis and apical redistribution of Na+/K+ ATPase. EspF binds to sorting nexin 9 (SNX9) causing membrane remodelling in host cells. Infection with ΔespF/pespFD3, a mutant strain that ablates EspF binding to SNX9, or inhibition of dynamin, attenuates Crb3 endocytosis caused by EPEC. In addition, infection with ΔespF/pespFD3 has no impact on Na+/K+ ATPase endocytosis. These data support the hypothesis that EPEC perturbs apical–basal polarity in an EspF‐dependent manner, which would contribute to EPEC‐associated diarrhoea by disruption of TJ and altering the crucial positioning of membrane transporters involved in the absorption of ions and solutes. 相似文献
10.
Sharon P. Andreoli Coleen P. Mallett James A. McAteer Stephen A. Kempson Naomi Fineberg 《In vitro cellular & developmental biology. Animal》1998,34(10):824-830
Summary In renal tubular epithelial cells, oxidant injury results in several metabolic alterations including ATP depletion, decreased
Na+K+ ATPase activity, and altered intracellular sodium and potassium content. To investigate the recovery of LLC-PK1 cells following
oxidant injury and to determine if recovery can be accelerated, we induced oxidant stress in LLC-PK1 cells with 500 μM hydrogen peroxide for 60 min. Identical cohorts of oxidant-stressed cells were incubated in recovery medium without epidermal
growth factor (EGF) or recovery medium containing 25 ng EGF per ml. ATP levels, Na+K+ ATPase activity in whole cells, Na+K+ ATPase activity in disrupted cells, and intracellular sodium and potassium ion content were determined at 0, 5, 24, 48, and
72 h following oxidant injury in each cohort of cells. In oxidant-stressed cells recovering in medium without EGF, ATP levels,
Na+K+ ATPase activity, and intracellular ion content improved but continued to remain substantially lower than control values at
all time points following oxidant stress. In cells recovering in medium with EGF, ATP levels, Na+K+ ATPase activity, and the intracellular potassium-to-sodium ratio were significantly higher at nearly all time points than
values in cells recovering in medium alone. In cells recovering with added EGF, Na+K+ ATPase activity had improved to control levels, whereas ATP levels and intracellular ion content approached control values
by 72 h following oxidant stress. We conclude that oxidant-mediated ATP depletion, altered Na+K+ ATPase activity, and intracellular ion content remain depressed for several d following oxidant stress and that EGF accelerated
recovery of LLC-PK1 cells from oxidant injury. 相似文献
11.
The efficiency of (Na+ + K+)-ATPase (i.e. the amount of K+ pumped per ATP hydrolyzed) in intact tumorigenic cells was estimated in this study. This was accomplished by simultaneously measuring the rate of ouabain-sensitive K+ uptake and oxygen consumption in tumorigenic cell suspensions during the reintroduction of K+ to K+-depleted cells. The ATP turnover was then estimated by assuming 5.6–6 ATP/O2 as the stoichiometry of NADH-linked respiration in these cells. In the three cell lines tested (hamster and chick embryo cells transformed with Rous sarcoma virus and Ehrlich ascites cells), the K+/ATP ratio was approximately 2, the same value as that found in normal tissues. Furthermore, only 20% of the total ATP production of these cells was used by (Na+ + K+)-ATPase. 相似文献
12.
Modifications of some membranal enzymatic activities in rabbit brain edema induced by cold injury were studied. The edema was characterized by the tissue H2O content and the K+/Na+ ratio. Comparison of the respiratory rate of isolated mitochondria in the state 3 and 4 and the ADP/O ratio suggested an alteration in the ATP synthesis mechanism. The oligomycin sensitive ATPase activity was severely reduced in mitochondria isolated from edematous cells. The alteration of the ouabain sensitive Na+-K+-ATPase was first qualitative in the sense where the response of the ATPase to the K+/Na+ ratio was modified. A loss of the total activity was then observed. Intravenous injection of CDP choline induced a regression of the edema, a restoration of the sensitivity of the mitochondrial ATPase towards oligomycin and a restoration of the sensitivity of the Na+-K+-ATPase to the K+/Na+ ratio. These results suggest that the reversible damages of the cells induced by cold injury were due to a disorder at the protein-lipid interaction level. 相似文献
13.
The K+ and Na+ concentrations in living cells are strictly regulated at almost constant concentrations, high for K+ and low for Na+. Because these concentrations correspond to influx-efflux steady states, K+ and Na+ effluxes and the transporters involved play a central role in the physiology of cells, especially in environments with high Na+ concentrations where a high Na+ influx may be the rule. In eukaryotic cells two P-type ATPases are crucial in these homeostatic processes, the Na,K-ATPase of animal cells and the H+-ATPase of fungi and plants. In fungi, a third P-type ATPase, the ENA ATPase, was discovered nineteen years ago. Although for many years it was considered to be exclusively a fungal enzyme, it is now known to be present in bryophytes and protozoa. Structurally, the ENA (from exitus natru: exit of sodium) ATPase is very similar to the sarco/endoplasmic reticulum Ca2+ (SERCA) ATPase, and it probably exchanges Na+ (or K+) for H+. The same exchange is mediated by Na+ (or K+)/H+ antiporters. However, in eukaryotic cells these antiporters are electroneutral and their function depends on a ΔpH across the plasma membrane. Therefore, the current notion is that the ENA ATPase is necessary at high external pH values, where the antiporters cannot mediate uphill Na+ efflux. This occurs in some fungal environments and at some points of protozoa parasitic cycles, which makes the ENA ATPase a possible target for controlling fungal and protozoan parasites. Another technological application of the ENA ATPase is the improvement of salt tolerance in flowering plants. 相似文献
14.
Treatment of bovine pulmonary smooth muscle cells with U46619 inhibited the Na+/K+ ATPase activity in two parallel pathways: one of which is mediated via glutathionylation of the pump and the other by augmenting the inhibitory activity of the 70 kDa inhibitor protein of Na+/K+ ATPase. Although phospholemman deglutathionylates the pump leading to its activation, the inhibitor is responsible for irreversible inhibition of Na+/K+ ATPase in an isoform specific manner during treatment of the cells with U46619. 相似文献
15.
Potassium uptake was studied in Down's syndrome (D.S.) platelets to determine if the Na+/K+ ATPase mediated movement of this ion was decreased compared to normal platelets. Total uptake of 42K was 1.58±0.16 μmoles/hr/109 normal platelets but was decreased to 1.06±0.06 μmoles/hr/109 D.S. platelets (p<.001). Na+/K+ ATPase mediated (ouabain sensitive) K+ uptake was 0.87±0.05 μmoles/hr/109 normal platelets but only 0.54±0.04 μmoles/hr/109 in D.S. platelets (p<.001). As the Na+/K+ ATPase mediated outward movement of Na+ is decreased in D.S. platelets, the present work demonstrates that bidirectional functional imparrment of the Na+/K+ ATPase pump is present in D.S. platelets. 相似文献
16.
The principles of enzyme kinetic analysis were applied to quantitate the relationships among serum-derived growth factors, nutrients, and the rate of survival and multiplication of human fibroblasts in culture. The survival or multiplication rate of a population of cells plotted against an increasing concentration of a growth factor or nutrient in the medium exhibited a hyperbolic pattern that is characteristic of a dissociable, saturable interaction between cells and the ligands. Parameters equivalent to the Km and Vmax of enzyme kinetics were assigned to nutrients and growth factors. When all nutrient concentrations were optimized and in steady state, serum factors accelerated the rate of multiplication of a normal cell population. The same set of nutrients that supported a maximal rate of multiplication in the presence of serum factors supported the maintenance of non-proliferating cells in the absence of serum factors. Therefore, under this condition, serum factors are required for cell division and play a purely regulatory iole in multiplication of the cell population. The quantitative requirement for 18 nutrients of 29 that were examined was significantly higher (P < 0.001) for cell multiplication in the presence of serum factors than for cell maintenance in the absence of serum factors. This indicated specific nutrients that may be quantitatively important in cell division processes as well as in cell maintenance. The quantitative requirement for Ca2+, Mg2+, K+, Pi, and 2-oxocarboxylic acid for cell multiplication was modified by serum factors and other purified growth factors. The requirement for over 30 other nutrients could not clearly be related to the level of serum factors in the medium. Serum factors also determined the Ca2+, K+, and 2-oxocarboxylic acid requirement for maintenance of non-proliferating cells. Therefore, when either Ca2+, K+, or 2-oxocarboxylic acid concentration was limiting, factors in serum played a role as cell “survival or maintenance” factors in addition to their role in cell division as “growth regulatory” factors. However, with equivalent levels of serum factors in the medium, the requirement for Ca2+, K+, and 2-oxocarboxylic acids was still much higher for multiplication than for maintenance. Kinetic analysis revealed that the concentrations of individual nutrients modify the quantitative requirement for others for cell multiplication in a specific pattern. Thus, specific quantitative relationships among different nutrients in the medium are important in the control of the multiplication rate of the cell population. When all nutrient concentrations were optimal for multiplication of normal cells, the multiplication response of SV40-virus-transformed cells to serum factors was similar to that of normal cells. When serum factors were held constant, transformed cells required significantly less (P < 0.001) of 12 of the 26 nutrients examined. Therefore, the transformed cells only have a growth advantage when the external concentration of specific nutrients limits the multiplication rate of normal cells. Taken together, the results suggest that the control of cell multiplication is intimately related to external concentrations of nutrients. Specific growth regulatory factors may stimulate cell proliferation by modification of the response of normal cells to nutrients. Transforming agents may confer a selective growth advantage on cells by a constitutive alteration of their response to extracellular nutrients. 相似文献
17.
The effect of d-aldosterone on human erythrocyte ghost (Na+ + K+)-Mg ATPase has been studied. Aldosterone at 3.225 × 10?10M caused a 450% activation of (Na+ + K+)-Mg ATPase activity whilst inhibiting (Na+ + Na+)-Mg ATPase activity. Aldosterone acts by reducing the affinity of the external K+ site of (Na+ + K+)Mg ATPase for Na+ thereby resulting in improved efficiency of Na+ ? K+ transfer. Aldosterone was additionally found to modify both the Na+ and K+ activation of (Na+ + K+)Mg ATPase incubated in the presence of commercial ATP containing orthovanadate. Aldosterone was found to reverse the inhibitory effects of orthovanadate at high Na+ and K+ concentrations. The physiological significance of orthovanadate and aldosterone are discussed. 相似文献
18.
Treatment of Friend erythroleukemia cells with several different chemical agents causes an early decrease in the 86Rb+ influx mediated by Na+/K+ adenosine triphosphatase (ATPase). These agents, which induced Friend cells to differentiate, include dimethylsulfoxide (DMSO), ouabain, hypoxanthine, and actinomycin D. The magnitude of the early decrease in 86Rb+ influx correlates with the proportion of cells in cultures of inducible Friend cell clones which later go on to synthesize hemoglobin. Compounds which do not incude differentiation in these cells, such as xanthine, exogenous hematin, and erythropoietin, do not cause a change in 86Rb+ influx. A change in the intracellular K+ ion concentration does not occur during induction by DMSO because, although there is a decrease in K+ content per cell soon after induction, there is a parallel decrease in cell volume. These results and previous observations from this laboratory are discussed in terms of the posible involvement of the Na+/K+ ATPase in Friend cell differentiation. 相似文献
19.
G. Sachs K. Munson V. N. Balaji D. Aures-Fischer S. J. Hersey K. Hall 《Journal of bioenergetics and biomembranes》1989,21(5):573-588
The gastric H+ + K+ ATPase is a member of the phosphorylating class of transport ATPase. Based on sequence homologies and CHO content, there may be ab subunit associated with the catalytic subunit of the H+ + K+ ATPase. Its function, if present, is unknown. The pump catalyzes a stoichiometric exchange of H+ for K+, but is also able to transport Na+ in the forward direction. This suggests that the transport step involves hydronium rather than protons. The initial binding site is likely to contain a histidine residue to account for the high affinity of the cellular site. The extracellular site probably lacks this histidine, so that a low affinity for hydronium allows release into a solution of pH 0.8. Labelling with positively charge, luminally reactive reagents that block ATPase and pump activity has shown that a region containing H5 and H6 and the intervening luminal loop is involved in necessary conformational changes for normal pump activity. The calculated structure of this loop shows the presence of ana helical,b turn, andb strand sector, with negative charges close to the membrane domain. This sector provides a possible site of interaction of drugs with the H+ + K+ ATPase, and may be part of the K+ pathway in the enzyme.Emory University, Atlanta, Georgia. 相似文献
20.
Changes in intracellular elemental (Na, K) concentrations caused by cytochalasin B were measured by electron probe microanalysis. Cytochalasin B is applied to transfer somatic cell nuclei into early embryo cells. This chemical causes a cytoskeleton rearrangement that may activate potassium channels, which, in turn, results in a cytoplasmic Na+/K+ imbalance. Our study showed that cytochalasin B reduced the intracellular sodium concentration. After the exposure of the mouse embryo with Dulbecco’s solution free from chemical, the Na+/K+ balance in cytoplasm reached the initial level. Possible mechanisms of registered changes in intracellular Na+ concentration are discussed. 相似文献