共查询到20条相似文献,搜索用时 203 毫秒
1.
The expression of Na+, K+-ATPase α3 subunit and synaptosomal membrane Na+, K+-ATPase activity were analyzed after administration of ouabain and endobain E, respectively commercial and endogenous Na+, K+-ATPase inhibitors. Wistar rats received intracerebroventricularly ouabain or endobain E dissolved in saline solution or Tris–HCl,
respectively or the vehicles (controls). Two days later, animals were decapitated, cerebral cortex and hippocampus removed
and crude and synaptosomal membrane fractions were isolated. Western blot analysis showed that Na+, K+-ATPase α3 subunit expression increased roughly 40% after administration of 10 or 100 nmoles ouabain in cerebral cortex but
remained unaltered in hippocampus. After administration of 10 μl endobain E (1 μl = 28 mg tissue) Na+, K+-ATPase α3 subunit enhanced 130% in cerebral cortex and 103% in hippocampus. The activity of Na+, K+-ATPase in cortical synaptosomal membranes diminished or increased after administration of ouabain or endobain E, respectively.
It is concluded that Na+, K+-ATPase inhibitors modify differentially the expression of Na+, K+-ATPase α3 subunit and enzyme activity, most likely involving compensatory mechanisms. 相似文献
2.
K. O. Grishanin V. Yu. Tashkin A. A. Lenz H. J. Apell V. S. Sokolov 《Biochemistry (Moscow) Supplemental Series A: Membrane and Cell Biology》2010,4(4):397-402
The effect of pH on electrogenic sodium transport by the Na+,K+-ATPase has been studied. Experiments were carried out by admittance recording in a model system consisting of a bilayer lipid
membrane with adsorbed membrane fragments containing purified Na+,K+-ATPase. Changes in the membrane admittance (capacitance and conductance increments in response to photo-induced release of
ATP from caged ATP) were measured as function of AC voltage frequency, sodium ion concentration, and pH. In solutions containing
150 mM Na+, the frequency dependence of capacitance increments was not significantly dependent on pH in the range between 6 and 8. At
a low NaCl concentration (3 mM), the capacitance increments at low frequencies decreased with the increasing pH. In the absence
of NaCl, the frequency-dependent capacitance increment at low frequencies was similar to that measured in the presence of
3 mM NaCl. These results may be explained by involvement of protons in the Na+,K+-ATPase pump cycle, i.e., electroneutral exchange of sodium ions for protons under physiological conditions, electrogenic
transport of sodium ions at high pH, and electrogenic transport of protons at low concentrations (and in the absence) of sodium
ions. 相似文献
3.
Garçon DP Lucena MN França JL McNamara JC Fontes CF Leone FA 《The Journal of membrane biology》2011,244(1):9-20
We investigated the effect of the exogenous polyamines spermine, spermidine and putrescine on modulation by ATP, K+, Na+, NH4
+ and Mg2+ and on inhibition by ouabain of posterior gill microsomal Na+,K+-ATPase activity in the blue crab, Callinectes ornatus, acclimated to a dilute medium (21‰ salinity). This is the first kinetic demonstration of competition between spermine and
spermidine for the cation sites of a crustacean Na+,K+-ATPase. Polyamine inhibition is enhanced at low cation concentrations: spermidine almost completely inhibited total ATPase
activity, while spermine inhibition attained 58%; putrescine had a negligible effect on Na+,K+-ATPase activity. Spermine and spermidine affected both V and K for ATP hydrolysis but did not affect ouabain-insensitive ATPase activity. ATP hydrolysis in the absence of spermine and
spermidine obeyed Michaelis–Menten behavior, in contrast to the cooperative kinetics seen for both polyamines. Modulation
of V and K by K+, Na+, NH4
+ and Mg2+ varied considerably in the presence of spermine and spermidine. These findings suggest that polyamine inhibition of Na+,K+-ATPase activity may be of physiological relevance to crustaceans that occupy habitats of variable salinity. 相似文献
4.
María G. López Ordieres Georgina Rodríguez de Lores Arnaiz 《Neurochemical research》2009,34(12):2226-2232
Na+, K+-ATPase is inhibited by neurotensin, an effect which involves the peptide high affinity receptor (NTS1). Neurotensin effect
on cerebral cortex synaptosomal membrane Na+, K+-ATPase activity of rats injected i.p. with antipsychotic clozapine was studied. Whereas 3.5 × 10−6 M neurotensin decreased 44% Na+, K+-ATPase activity in the controls, the peptide failed to modify enzyme activity 30 min after a single 3.0, 10.0 and 30.0 mg/kg
clozapine dose. Neurotensin decreased Na+, K+-ATPase activity 40 or 20% 18 h after 3.0 or 5.6 mg/kg clozapine administration, respectively, and lacked inhibitory effect
18 h after 17.8 and 30.0 mg/kg clozapine doses. Results indicated that the clozapine treatment differentially modifies the
further effect of neurotensin on synaptosomal membrane Na+, K+-ATPase activity according to time and dose conditions employed. Taken into account that clozapine blocks the dopaminergic
D2 receptor, findings obtained favor the view of an interplay among neurotensinergic receptor, dopaminergic D2 receptor and
Na+, K+-ATPase at synaptic membranes. 相似文献
5.
Mi Seon Park Hyun Suk Shin Gyung-Suk Kil Jehee Lee Cheol Young Choi 《Ichthyological Research》2011,58(3):195-201
We examined changes in the expression of Na+/K+-ATPase mRNA in the gills of the cinnamon clownfish using quantitative real-time PCR in an osmotically changing environment
[seawater (35 psu; practical salinity unit, 1 psu ≈ 1‰) → brackish water (17.5 psu) and brackish water with prolactin]. The
expression of Na+/K+-ATPase mRNA in gills was increased after the transfer to brackish water, and the expression was repressed by prolactin treatment.
Also, activities of gill Na+/K+-ATPase and plasma cortisol levels increased after the transfer to brackish water and were repressed in brackish water with
prolactin treatment. Na+/K+-ATPase-immunoreactive cells were almost consistently observed in the gill filaments, but absent from the lamella epithelia.
The plasma osmolality level decreased in brackish water, but the level of this parameter increased in brackish water with
prolactin treatment during salinity change. These results suggest that the Na+/K+-ATPase gene plays an important role in osmoregulation in gills, and prolactin improves the hyperosmoregulatory ability of
cinnamon clownfish in a brackish water (hypoosmotic) environment. 相似文献
6.
Pillans RD Good JP Anderson WG Hazon N Franklin CE 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》2005,175(1):37-44
This study examined the osmoregulatory status of the euryhaline elasmobranch Carcharhinus leucas acclimated to freshwater (FW) and seawater (SW). Juvenile C. leucas captured in FW (3 mOsm l–1 kg–1) were acclimated to SW (980–1,000 mOsm l–1 kg–1) over 16 days. A FW group was maintained in captivity over a similar time period. In FW, bull sharks were hyper-osmotic regulators, having a plasma osmolarity of 595 mOsm l–1 kg–1. In SW, bull sharks had significantly higher plasma osmolarities (940 mOsm l–1 kg–1) than FW-acclimated animals and were slightly hypo-osmotic to the environment. Plasma Na+, Cl–, K+, Mg2+, Ca2+, urea and trimethylamine oxide (TMAO) concentrations were all significantly higher in bull sharks acclimated to SW, with urea and TMAO showing the greatest increase. Gill, rectal gland, kidney and intestinal tissue were taken from animals acclimated to FW and SW and analysed for maximal Na+/K+-ATPase activity. Na+/K+-ATPase activity in the gills and intestine was less than 1 mmol Pi mg–1 protein h–1 and there was no difference in activity between FW- and SW-acclimated animals. In contrast Na+/K+-ATPase activity in the rectal gland and kidney were significantly higher than gill and intestine and showed significant differences between the FW- and SW-acclimated groups. In FW and SW, rectal gland Na+/K+-ATPase activity was 5.6±0.8 and 9.2±0.6 mmol Pi mg–1 protein h–1, respectively. Na+/K+-ATPase activity in the kidney of FW and SW acclimated animals was 8.4±1.1 and 3.3±1.1 Pi mg–1 protein h–1, respectively. Thus juvenile bull sharks have the osmoregulatory plasticity to acclimate to SW; their preference for the upper reaches of rivers where salinity is low is therefore likely to be for predator avoidance and/or increased food abundance rather than because of a physiological constraint. 相似文献
7.
A. M. Tverskoi S. V. Sidorenko E. A. Klimanova O. A. Akimova L. V. Smolyaninova O. D. Lopina S. N. Orlov 《Biochemistry. Biokhimii?a》2016,81(8):876-883
Side-by-side with inhibition of the Na+,K+-ATPase ouabain and other cardiotonic steroids (CTS) can affect cell functions by mechanisms other than regulation of the intracellular Na+ and K+ ratio ([Na+]i/[K+]i). Thus, we compared the doseand time-dependences of the effect of ouabain on intracellular [Na+]i/[K+]i ratio, Na+,K+-ATPase activity, and proliferation of human umbilical vein endothelial cells (HUVEC). Treatment of the cells with 1-3 nM ouabain for 24-72 h decreased the [Na+]i/[K+]i ratio and increased cell proliferation by 20-50%. We discovered that the same ouabain concentrations increased Na+,K+-ATPase activity by 25-30%, as measured by the rate of 86Rb+ influx. Higher ouabain concentrations inhibited Na+,K+-ATPase, increased [Na+]i/[K+]i ratio, suppressed cell growth, and caused cell death. When cells were treated with low ouabain concentrations for 48 or 72 h, a negative correlation between [Na+]i/[K+]i ratio and cell growth activation was observed. In cells treated with high ouabain concentrations for 24 h, the [Na+]i/[K+]i ratio correlated positively with proliferation inhibition. These data demonstrate that inhibition of HUVEC proliferation at high CTS concentrations correlates with dissipation of the Na+ and K+ concentration gradients, whereas cell growth stimulation by low CTS doses results from activation of Na+,K+-ATPase and decrease in the [Na+]i/[K+]i ratio. 相似文献
8.
L. V. Karpova E. E. Akkuratov E. R. Bulygina A. A. Boldyrev 《Biochemistry (Moscow) Supplemental Series A: Membrane and Cell Biology》2008,2(2):156-160
Three-hour incubation of rat cerebellar granule cells with 0.1 μM ouabain increases intracellular levels of Ca2+ ions and reactive oxygen species (ROS) resulting in pronounced activation of Mitogen-Activated Protein Kinase (MAPK). Higher concentrations of ouabain induce further increases in MAPK activity. The activating effect of ouabain is attenuated by the NMDA-receptor antagonists MK-801 and D-AP5. The data obtained suggest that similar to NMDA receptors ouabain-sensitive and ouabain-resistant isoforms of Na+,K+-ATPase are actively involved in intracellular signaling cascades controlling proliferative activity of neuronal cells. 相似文献
9.
P. A. Abramicheva T. A. Balakina O. A. Bulaeva A. A. Guseva O. D. Lopina O. V. Smirnova 《Biochemistry. Biokhimii?a》2017,82(5):632-641
Participation of Na+/K+-ATPase in the natriuretic effect of prolactin in a cholestasis of pregnancy model was investigated. The Na+/K+-ATPase activity in rat kidney medulla, where active sodium reabsorption occurs, decreased in the model of cholestasis of pregnancy and other hyperprolactinemia types compared with intact animals. This effect was not connected with the protein level of α1- and β-subunits of Na+/K+-ATPase measured by Western blotting in the kidney medulla. Decrease in Na+/K+-ATPase activity in the kidney cortex was not significant, as well as decrease in the quantity of mRNA and proteins of the α1- and β-subunits of Na+/K+-ATPase. There were no correlations between the Na+/K+-ATPase activity and sodium clearance, although sodium clearance increased significantly in the model of cholestasis of pregnancy and other hyperprolactinemia groups under conditions of stable glomerular filtration rate measured by creatinine clearance. We conclude that the Na+/K+-ATPase is not the only mediator of the natriuretic effect of prolactin in the model of cholesta- sis of pregnancy. 相似文献
10.
Haruo Homareda Masahiro Otsu Sachiko Yamamoto Makoto Ushimaru Sayaka Ito Toshiyuki Fukutomi Taeho Jo Yoshinobu Eishi Yukichi Hara 《Journal of bioenergetics and biomembranes》2017,49(6):463-472
The affinity for K+ of silkworm nerve Na+/K+-ATPase is markedly lower than that of mammalian Na+/K+-ATPase (Homareda 2010). In order to obtain clues on the molecular basis of the difference in K+ affinities, we cloned cDNAs of silkworm (Bombyx mori) nerve Na+/K+-ATPase α and β subunits, and analyzed the deduced amino acid sequences. The molecular masses of the α and β subunits were presumed to be 111.5 kDa with ten transmembrane segments and 37.7 kDa with a single transmembrane segment, respectively. The α subunit showed 75% identity and 93% homology with the pig Na+/K+-ATPase α1 subunit. On the other hand, the amino acid identity of the β subunit with mammalian counterparts was as low as 30%. Cloned α and β cDNAs were co-expressed in cultured silkworm ovary-derived cells, BM-N cells, which lack endogenous Na+/K+-ATPase. Na+/K+-ATPase expressed in the cultured cells showed a low affinity for K+ and a high affinity for Na+, characteristic of the silkworm nerve Na+/K+-ATPase. These results suggest that the β subunit is responsible for the affinity for K+ of Na+/K+-ATPase. 相似文献
11.
Several researches attempt to protect diabetic patients from the development of nephropathy. Involvement of leptin and renal
Na+,K+-ATPase enzyme in diabetic nephropathy (DN) development is a recent field for researches. Vanadium, as a trace element with
insulin mimetic effect, may act synergistically with insulin to protect against the development of DN. Sixty male Sprague
Dawley rats were divided into six groups: control group (C), vanadium control group (CV), streptozotocin-induced diabetic
group (D), insulin-treated diabetic group (DI), vanadium-treated diabetic group (DV), and combined insulin and vanadium-treated
diabetic group. Six weeks later, systolic blood pressure (SBP) was measured and retro-orbital blood samples were collected
to estimate glycosylated hemoglobin (HbA1c), serum sodium (Na+) and creatinine, blood urea nitrogen (BUN) and plasma leptin levels. Preparation of microsomal fraction of renal tissue homogenate
for estimation of Na+,K+-ATPase activity was done. The D group showed a significant increase in SBP, HbA1c, serum Na+, creatinine, and BUN levels and Na+,K+-ATPase activity in microsomal fraction of renal tissue homogenate while plasma leptin level decreased significantly compared
with C and CV groups. Both DI and DV groups showed a significant improvement in all the above measured parameters compared
with D group while there were no significant changes between the DI and DV groups. Concomitant treatment with insulin and
vanadium resulted in a significant improvement in all the measured parameters compared to each alone. Vanadium in combination
with insulin ameliorates DN markers and reduces renal Na+,K+-ATPase overactivity in diabetic rats. An effect that may be partially mediated through correction of hypoleptinemia observed
in these animals. 相似文献
12.
Alicia Gutnisky María Graciela López Ordieres Georgina Rodríguez de Lores Arnaiz 《Neurochemical research》2016,41(6):1274-1280
Neurotensin behaves as a neuromodulator or as a neurotransmitter interacting with NTS1 and NTS2 receptors. Neurotensin in vitro inhibits synaptosomal membrane Na+, K+-ATPase activity. This effect is prevented by administration of SR 48692 (antagonist for NTS1 receptor). The administration of levocabastine (antagonist for NTS2 receptor) does not prevent Na+, K+-ATPase inhibition by neurotensin when the enzyme is assayed with ATP as substrate. Herein levocabastine effect on Na+, K+-ATPase K+ site was explored. For this purpose, levocabastine was administered to rats and K+-p-nitrophenylphosphatase (K+-p-NPPase) activity in synaptosomal membranes and [3H]-ouabain binding to cerebral cortex membranes were assayed in the absence (basal) and in the presence of neurotensin. Male Wistar rats were administered with levocabastine (50 μg/kg, i.p., 30 min) or the vehicle (saline solution). Synaptosomal membranes were obtained from cerebral cortex by differential and gradient centrifugation. The activity of K+-p-NPPase was determined in media laking or containing ATP plus NaCl. In such phosphorylating condition enzyme behaviour resembles that observed when ATP hydrolyses is recorded. In the absence of ATP plus NaCl, K+-p-NPPase activity was similar for levocabastine or vehicle injected (roughly 11 μmole hydrolyzed substrate per mg protein per hour). Such value remained unaltered by the presence of 3.5 × 10?6 M neurotensin. In the phosphorylating medium, neurotensin decreased (32 %) the enzyme activity in membranes obtained from rats injected with the vehicle but failed to alter those obtained from rats injected with levocabastine. Levocabastine administration enhanced (50 %) basal [3H]-ouabain binding to cerebral cortex membranes but failed to modify neurotensin inhibitory effect on this ligand binding. It is concluded that NTS2 receptor blockade modifies the properties of neuronal Na+, K+-ATPase and that neurotensin effect on Na+, K+-ATPase involves NTS1 receptor and -at least partially- NTS2 receptor. 相似文献
13.
Crush syndrome (CS) results from severe traumatic damage to the organism that is characterized by stress, acute homeostatic
failure of the tissues, and myoglobinuria with severe intoxication. This leads to an acute impairment of kidneys and heart.
The peripheral and central nervous systems are also the subject of significant changes in CS. Na+, K+-ATPase is a critical enzyme in neuron that is essential for the regulation of neuronal membrane potential, cell volume as
well as transmembrane fluxes of Ca++ and Excitatory Amino Acids. In the present study, Na+, K+-ATPase activity of rat brain regions [Olfactory lobes (OL), Cerebral cortex (CC), Cerebellum (CL), and Medulla oblongata
(MO)] during CS was investigated. Experimental model of CS in albino rats was induced by 2-h of compression followed by 2,
24, and 48-h of decompression of femoral muscle tissue. In this study, we have observed elevation in Na+, K+-ATPase activity above normal/control levels in all parts of brain (OL: 34.4%; CC: 1.0%; CL: 3.3% and MO: 45%) during 2-h
compression in comparison to controls. 相似文献
14.
O. A. Akimova L. V. Kapilevich S. N. Orlov O. D. Lopina 《Biochemistry. Biokhimii?a》2016,81(9):1013-1022
Prolonged exposure of different epithelial cells (canine renal epithelial cells (MDCK), vascular endothelial cells from porcine aorta (PAEC), human umbilical vein endothelial cells (HUVEC), cervical adenocarcinoma (HeLa), as well as epithelial cells from colon carcinoma (Caco-2)) with ouabain or with other cardiotonic steroids was shown earlier to result in the death of these cells. Intermediates in the cell death signal cascade remain unknown. In the present study, we used proteomics methods for identification of proteins whose interaction with Na+,K+-ATPase is triggered by ouabain. After exposure of Caco-2 human colorectal adenocarcinoma cells with 3 μM of ouabain for 3 h, the protein interacting in complex with Na+,K+-ATPase was coimmunoprecipitated using antibodies against the enzyme α1-subunit. Proteins of coimmunoprecipitates were separated by 2D electrophoresis in polyacrylamide gel. A number of proteins in the coimmunoprecipitates with molecular masses of 71-74, 46, 40-43, 38, and 33-35 kDa was revealed whose binding to Na+,K+-ATPase was activated by ouabain. Analyses conducted by mass spectroscopy allowed us to identify some of them, including seven signal proteins from superfamilies of glucocorticoid receptors, serine/threonine protein kinases, and protein phosphatases 2C, Src-, and Rho-GTPases. The possible participation of these proteins in activation of cell signaling terminated by cell death is discussed. 相似文献
15.
N. N. Nemova E. I. Kaivarainen N. N. Fokina 《Applied Biochemistry and Microbiology》2017,53(6):699-702
Changes in the activity of Na+/K+-ATPase and content of membrane lipids (phospholipids) in the gills and hepatopancreas of the blue mussel Mytilus edulis L. have been studied during a sharp temperature increase under aquarian managed conditions. The most pronounced changes were recorded in mollusk gills. A correlation of changes in the activity of membrane-bound Na+/K+-ATPase and phospholipid content (mainly phosphatidylserine, phosphatidylinositol, phosphatidylethanolamine, and lysophosphatidylcholine) was revealed; this correlation evidences their mutual involvement in compensation for the temperature effect to help mussels adapt to sharp temperature changes. 相似文献
16.
Role of Energized States of (Na<Superscript>+</Superscript> + K<Superscript>+</Superscript>-ATPase in the Sodium Pump 总被引:1,自引:0,他引:1
IN an earlier paper1 we have presented a model for a sodium pump based on the operation of the adenosine triphosphatase component of membranes which is sensitive to ouabain and is activated by sodium and potassium; that is (Na++K+)-ATPase. We attempted to correlate the biochemical properties of this enzyme system as they were then known with the essential properties of Na+ transport systems. The model suggested further experiments which could clarify the role of (Na+ + K +)-ATPase in ion transport and some experimental evidence is now available for the stoichiometry of ouabain binding to isolated enzyme preparations2,3 although differences in the experimental techniques which have been used make the data equivocal. 相似文献
17.
Busanello EN Viegas CM Tonin AM Grings M Moura AP de Oliveira AB Eichler P Wajner M 《Neurochemical research》2011,36(6):1101-1107
Pristanic acid (Prist) accumulates in some peroxisomal disorders characterized by neurologic dysfunction and brain abnormalities.
The present work investigated the in vitro effects of Prist on important parameters of energy metabolism in brain cortex of
young rats. CO2 production from labeled acetate and the activities of the respiratory chain complexes I–IV, creatine kinase and synaptic
Na+, K+-ATPase were measured. Prist decreased CO2 production and the activities of complexes I, II and II–III. Prist also reduced Na+, K+-ATPase activity, but did not affect the activity of creatine kinase. Considering the importance of the citric acid cycle
and the electron flow through the respiratory chain for brain energy production and of Na+, K+-ATPase for the maintenance of membrane potential, the present data indicate that Prist compromises brain bioenergetics and
neurotransmission. It is presumed that these pathomechanisms may be involved in the neurological damage found in patients
affected by disorders in which Prist accumulates. 相似文献
18.
I. Yu. Petrushanko V. A. Mitkevich V. A. Borzova S. S. Yakushev O. D. Lopina A. A. Makarov 《Biophysics》2009,54(6):686-690
The Na+/K+-ATPase generates an electrochemical gradient of Na+ and K+, which is necessary for the functioning of animal cells. During the catalytic act, the enzyme passes through two principal
conformational states, E1 and E2. To assess the domain organization of the protein in these conformations, thermal denaturation of Na+/K+-ATPases from duck salt gland and from rabbit kidney has been studied in the absence and in the presence of Na+ or K+, which induce the transition to E1 or E2. The melting curves for the ion-free forms of the two ATPases have different shapes: the rabbit protein shows one transition
at 56.1°C, whereas the duck protein shows two transitions, at 49.8 and 56.9°C. Addition of Na+ or K+ ions abolishes the difference in thermal behavior between these enzymes, but through opposite effects. The melting curves
for the E2 conformation (K+ bound) in both cases exhibit a single peak of heat absorption at ∼63°C. For the E1 conformation (Na+ bound), each melting curve has three peaks, indicating denaturation of three domains. The difference in the domain organization
of Na+/K+-ATPase in the E1 and E2 states may account for the different sensitivity to temperature, proteolysis, and oxidative stress
observed for the two enzyme conformations. 相似文献
19.
1. Patients affected by isovaleric acidemia (IVAcidemia) suffer from acute episodes of encephalopathy. However, the mechanisms
underlying the neuropathology of this disease are poorly known. The objective of the present study was to investigate the
in vitro effects of the metabolites that predominantly accumulate in IVAcidemia, namely isovaleric acid (IVA), 3-hydroxyisovaleric
acid (3-OHIVA) and isovalerylglycine (IVG), on important parameters of energy metabolism, such as 14CO2 production from acetate and the activities of the respiratory chain complexes I–IV, creatine kinase and Na+, K+-ATPase in synaptic plasma membranes from cerebral cortex homogenates of 30-day-old rats.
2. We observed that 3-OHIVA acid and IVG did not affect all the parameters analyzed. Similarly, 14CO2 production from acetate (Krebs cycle activity), the activities of creatine kinase, and of the respiratory chain complexes
was not modified by IVA. In contrast, IVA exposition to cortical homogenates provoked a marked inhibition of Na+, K+-ATPase activity. However, this activity was not changed when IVA was directly exposed to purified synaptic plasma membranes,
suggesting an indirect effect of this organic acid on the enzyme. Furthermore, pretreatment of cortical homogenates with α-tocopherol
and creatine totally prevented IVA-induced inhibition on Na+, K+-ATPase activity from synaptic plasma membranes, whereas glutathione (GSH) and the NO synthase inhibitor Nω-nitro-l-arginine methyl ester (L-NAME) did not alter this inhibition.
3. These data indicate that peroxide radicals were probably involved in this inhibitory effect. Since Na+, K+-ATPase is a critical enzyme for normal brain development and functioning and necessary to maintain neuronal excitability,
it is presumed that the inhibitory effect of IVA on this activity may be involved in the pathophysiology of the neurological
dysfunction of isovaleric acidemic patients. 相似文献
20.
Khoa T. D. Nguyen Jae-Won Shin Caroline Rae Ellas K. Nanitsos Gabriela B. Acosta David V. Pow Vlado Buljan Maxwell R. Bennett Paul L. Else Vladimir J. Balcar 《Neurochemical research》2009,34(10):1767-1774
The naturally occurring toxin rottlerin has been used by other laboratories as a specific inhibitor of protein kinase C-delta
(PKC-δ) to obtain evidence that the activity-dependent distribution of glutamate transporter GLAST is regulated by PKC-δ mediated
phosphorylation. Using immunofluorescence labelling for GLAST and deconvolution microscopy we have observed that d-aspartate-induced redistribution of GLAST towards the plasma membranes of cultured astrocytes was abolished by rottlerin.
In brain tissue in vitro, rottlerin reduced apparent activity of (Na+, K+)-dependent ATPase (Na+, K+-ATPase) and increased oxygen consumption in accordance with its known activity as an uncoupler of oxidative phosphorylation
(“metabolic poison”). Rottlerin also inhibited Na+, K+-ATPase in cultured astrocytes. As the glutamate transport critically depends on energy metabolism and on the activity of
Na+, K+-ATPase in particular, we suggest that the metabolic toxicity of rottlerin and/or the decreased activity of the Na+, K+-ATPase could explain both the glutamate transport inhibition and altered GLAST distribution caused by rottlerin even without
any involvement of PKC-δ-catalysed phosphorylation in the process. 相似文献