scholarly journals Cerebral Na+, K+-ATPase Activity during Exposure to and Recovery from Acute Ischemia

1982 ◽  
Vol 2 (4) ◽  
pp. 457-465 ◽  
Author(s):  
V. MacMillan
Keyword(s):  
Atpase Activity ◽  
Carotid Arteries ◽  
Normal Values ◽  
Membrane Lipids ◽  
Energy State ◽  
Thiobarbituric Acid ◽  
Water Soluble ◽  
Acute Ischemia ◽  
Reactive Material ◽  
Free Radical Lipid

This study documents the Na+, K+-ATPase activity as well as selected parameters of oxidative metabolism and electrophysiological function in rat brain exposed to ischemia produced by electrocautery of the vertebral arteries and reversible occlusion of the carotid arteries. During a 0.5-h ischemic exposure in which the electroencephalograph (EEG) was abolished and energy metabolism severely compromised the Na+, K+-ATPase showed a capability for enhanced activity (120–140% of control), On recirculation, the Na+, K+-ATPase activity showed a phasic pattern, which was characterized by normal values at 0.25–2 h, increased values (115–125% of control) at 3–24 h, and, finally, normal values at 72 h of recirculation, respectively. The maintenance of Na+, K+-ATPase integrity was correlated with a gradual return of EEG activity and virtually complete restitution of the cerebral energy state during the 72 h of recirculation. Measurements of thiobarbituric acid reactive material and water soluble antioxidant during ischemia and recirculation gave no evidence of the presence of significant free radical lipid peroxidation in this model. It is concluded that Na+, K+-ATPase and its associated membrane lipids are not irreversibly damaged by ischemia in which the tissue lactacidosis is limited to less than 20 μmol g−1.

A Simple Method for Estimation of Lipoxygenase and Cyclo-Oxygenase Pathways in Human Platelets - the Use of Thiobarbituric Acid Reaction

1980 ◽  
Vol 44 (02) ◽  
pp. 111-114 ◽  
Author(s):  
Hiroshi Takayama ◽  
Minoru Okuma ◽  
Haruto Uchino
Keyword(s):  
Time Course ◽  
Normal Values ◽  
Human Platelet ◽  
Thiobarbituric Acid ◽  
Human Platelets ◽  
Optimal Conditions ◽  
Experimental Conditions ◽  
Simple Method ◽  
Acid Reaction ◽  
Optimal Ph

SummaryTo develop a simple method for estimation of platelet lipoxygenase (PLO) and cyclo-oxygenase (PCO) pathways, the arachidonic acid (AA) metabolism of human platelet was investigated under various experimental conditions by the use of the thiobarbituric acid (TBA) reaction and a radioisotope technique. A TBA-reactive substance different from malondialdehyde (MDA) via PCO pathway was detected and shown to be derived from the PLO pathway. Since the optimal pH and time course of its formation were different from those of MDA formation via PCO pathway, PLO and PCO pathways were estimated by quantitating the TBA-reactive substances produced by the incubation of AA either with aspirin-treated platelets or with untreated ones, respectively, each under optimal conditions. Normal values expressed in terms of nmol MDA/108 platelets were 1.17±0.34 (M±SD, n = 31) and 0.79±0.15 (n = 31) for PLO and PCO pathways, respectively.

Inhibition of ATPase activity of E. coli F1 by the water-soluble carbodiimide EDC is due to modification of several carboxyls in the .beta. subunit

Biochemistry ◽  
1984 ◽  
Vol 23 (18) ◽  
pp. 4134-4140 ◽  
Author(s):  
Hans Ruedi Lotscher ◽  
Catherina DeJong ◽  
Roderick A. Capaldi
Keyword(s):  
Atpase Activity ◽  
Water Soluble ◽  
Beta Subunit ◽  
E Coli

scholarly journals Influence of dibornol-HES on electrophysiological parameters in the period of restoration of blood flow in rabbit myocardium

2018 ◽  
Vol 17 (4) ◽  
pp. 6-15
Author(s):  
M. A. Vaykshnorayte ◽  
V. A. Vityazev ◽  
N. A. Vahnina ◽  
V. D. Shadrina ◽  
M. A. Torlopov ◽  
...  
Keyword(s):  
Blood Flow ◽  
Coronary Occlusion ◽  
Ischemia Reperfusion ◽  
Myocardial Damage ◽  
Water Soluble ◽  
Control Group ◽  
Acute Ischemia ◽  
30Th Minute ◽  
Dispersion Of Repolarization ◽  
Experimental Group

Objective. Dibornol-HES, a water-soluble drug based on the derivative of 2,6-diisobornyl-4-methylphenol Dibornol conjugated with hydroxyethyl starch, can reduce the occurrence and severity of arrhythmias by preventive intravenous administration, but it is unknown whether the drug could reduce the myocardial arrhythmogenicity once ischemia has developed at the developed ischemia.Materials and methods. In the model of acute ischemia / reperfusion of the rabbit heart, the effect of Dibornol-HEC (80 mg/kg body weight of the animal) on the electrophysiological indices characterizing myocardial arrhythmogenicity (global and border dispersion of repolarization) was studied during the restoration of blood flow. In the model of acute ischemia / reperfusion with 64 unipolar epicardial leads, the activation-recovery intervals were measured and global and border dispersion of repolarization in the native rabbits (control group, n = 9) and in the rabbits treated by Dibornol-HES (on the 25th minute of occlusion, the experimental group, n = 6).Results. The introduction of Dibornol-HES did not lead to a change in the electrocardiographic parameters of rabbits. By the 30th minute of the coronary occlusion on the ECG in the animals of the control and the experimental groups, the intervals RR, QT, QTc were shortened (p < 0.05). In the animals of both groups by the 30th minute of coronary occlusion, the global dispersion of repolarization increased (p < 0.05), the boundary dispersion of repolarization also increased (p < 0.05), due to the decrease in the duration of the activation-recovery intervals in the ischemic zone (p < 0.05). During the 30-minute reperfusion the magnitude of the global dispersion of repolarization did not change in animals of the both groups, and the magnitude of the border dispersion of repolarization in the control rabbits decreased (p < 0.05), while in the rabbits treated by Dibornol-HES the border dispersion of repolarization did not changed.Conclusion. In rabbits of the experimental group, the values of the global and border dispersions of repolarization did not differ from those of the animals in the control group. Therefore, the administration to Dibornol-HES just prior to reperfusion does not lead to the decrease in the dispersion of repolarization increased as a result of acute ischemic myocardial damage.

Abstract WP259: Metabolomic Analysis of Ischemic Brain Tissue to Explore Specific Metabolic Pathway Assosiated With Cerebral Ischemia

Stroke ◽  
2016 ◽  
Vol 47 (suppl_1) ◽  
Author(s):  
Yusuke Yamamoto ◽  
Kohkichi Hosoda ◽  
Yasuhiro Irino ◽  
Jun Tanaka ◽  
Taichiro Imahori ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Western Blot ◽  
Brain Tissue ◽  
Water Soluble ◽  
Gas Chromatography Mass Spectrometry ◽  
Control Group ◽  
Acute Ischemia ◽  
Rt Pcr ◽  
Ischemic Lesion ◽  
Ischemic Brain

Objectives: We investigated metabolic profiles of brain tissue in middle cerebral artery occlusion (MCAO) model of rats to explore the specific changes associated with acute ischemia. Methods: Focal cerebral ischemia was induced in rats using filament occlusion of the MCA. Tissue samples from the ischemic lesion were collected before and after ischemia(0, 30, 60, 120min, n=7-10). Sham operated rats were treated in the same way except MCAO (n=10). Water-soluble metabolites were extracted and analyzed using gas-chromatography/mass-spectrometry(GS/MS). The obtained data were analyzed by multivariate statistics to explore metabolic pathways associated with ischemia. The associated metabolic enzymes were investigated with RT-PCR and Western blot. Results: About ninety metabolites were identified by GC/MS. Principal component analysis and heatmap demonstrated clear separation between ischemia and control group (Figures). The most significant changes were decrease of fructose-6-phosphate and ribulose-5-phosphate, increase of hydroxybutyrate, and increase of GABA with time. These results suggested acceleration of pentose phosphate pathway to increase NADPH, upregulation of keton metabolism and neuroprotection by GABA. RT-PCR and Western blot did not indicate significant changes of transcription and protein level of the enzymes involved in these pathways and suggested changes of the enzyme activity by modification after transcription or translation such as phosphorylation. Conclusions: These results suggested the presence of neuroprotective metabolic change in the ischemic brain.

Regulation of Ca(2+)-dependent ATPase activity in detergent-skinned vascular smooth muscle

1994 ◽  
Vol 267 (3) ◽  
pp. H1032-H1039 ◽  
Author(s):  
Y. Zhang ◽  
R. S. Moreland
Keyword(s):  
Atpase Activity ◽  
Myosin Light Chain ◽  
Carotid Arteries ◽  
Myosin Atpase ◽  
Development Phase ◽  
Force Development ◽  
Myosin Atpase Activity ◽  
Force Maintenance ◽  
Triton X ◽  
Mlc Phosphorylation

We measured force, actin-activated myosin adenosinetriphosphatase (ATPase) activity, and myosin light-chain (MLC) phosphorylation levels in Triton X-100 detergent-skinned media of swine carotid arteries. Pseudo-ATPase activity composed of MLC kinase and phosphatase activities contributed maximally 12% to steady-state tissue ATPase activity. An increase in the Ca2+ concentration ([Ca2+]) induced an increase in force, MLC phosphorylation, and actin-activated myosin ATPase activity; this protocol was defined as the force development phase of contraction. Force maintenance was defined as the state induced by decreasing the [Ca2+] after a maximal contraction. Lowering the [Ca2+] decreased MLC phosphorylation to levels similar to those measured during force development at each [Ca2+]. In contrast, force remained at elevated levels while actin-activated myosin ATPase activity fell to significantly lower levels than those measured during the development phase for each [Ca2+]. We suggest that the significantly lower actin-activated myosin ATPase activity observed during a state of elevated force, compared with the development phase of a contraction, is evidence of slowly cycling latch bridges.

scholarly journals Decreased Erythrocyte NA+,K+-ATPase Activity and Increased Plasma TBARS in Prehypertensive Patients

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Carlos Ricardo Maneck Malfatti ◽  
Leandro Tibiriçá Burgos ◽  
Alexandre Rieger ◽  
Cássio Luiz Rüdger ◽  
Janaína Angela Túrmina ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Atpase Activity ◽  
Cell Damage ◽  
Venous Blood ◽  
Thiobarbituric Acid ◽  
Normal Blood Pressure ◽  
Thiobarbituric Acid Reactive Substances ◽  
Normotensive Subjects ◽  
The Relationship ◽  
Membrane Cell

The essential hypertension has been associated with membrane cell damage. The aim of the present study is investigate the relationship between erythrocyte Na+,K+-ATPase and lipoperoxidation in prehypertensive patients compared to normotensive status. The present study involved the prehypertensive patients (systolic:136±7 mmHg; diastolic:86.8±6.3 mmHg;n=8) and healthy men with normal blood pressure (systolic:110±6.4 mmHg; diastolic:76.1±4.2 mmHg;n=8) who were matched for age (35±4years old). The venous blood samples of antecubital vein (5 mL) were collected into a tube containing sodium heparin as anticoagulant (1000 UI), and erythrocyte ghosts were prepared for quantifying Na+,K+-ATPase activity. The extent of the thiobarbituric acid reactive substances (TBARS) was determined in plasma. The statistical analysis was carried out by Student’st-test and Pearson’s correlation coefficient. AP<0.05was considered significant. The Na+,K+-ATPase activity was lower in prehypertensive patients compared with normotensive subjects (4.9 versus 8.0 nmol Pi/mg protein/min;P<0.05). The Na+,K+-ATPase activity correlated negatively with TBARS content (r=-0.6;P<0.05) and diastolic blood pressure (r=-0.84;P<0.05). The present study suggests that Na+,K+-ATPase activity reduction and elevation of the TBARS content may underlie the pathophysiological aspects linked to the prehypertensive status.

293 EFFECT OF GUAIAZULENE ON IN VITRO BOVINE EMBRYO PRODUCTION

2007 ◽  
Vol 19 (1) ◽  
pp. 262 ◽  
Author(s):  
I. Dimitriadis ◽  
E. A. Rekka ◽  
E. Vainas ◽  
G. S. Amiridis ◽  
C. A. Rekkas
Keyword(s):  
Lipid Peroxidation ◽  
Embryo Development ◽  
Antioxidant Properties ◽  
Thiobarbituric Acid ◽  
Early Embryo ◽  
Bovine Embryo ◽  
Embryo Production ◽  
Reactive Material

The substrates used in in vitro embryo production (IVP) mimic the in vivo fluids in which oocytes mature, oocytes are fertilized, and the early embryos develop (follicular and oviductal fluid). It is well established that oxidative stress negatively affects in vitro culture (IVC) outcomes. Guaiazulene (G) is a component of chamomile species oil with known antioxidant properties. In the present study, all IVP media were modified by the addition of G solutions so that the former exhibited a total protection against induced lipid peroxidation (TPaLP) similar to that of the respective in vivo environment. The IVP outcomes were then compared between G-processed and control oocytes. Bovine preovulatory follicular (BF) and oviductal (BO) fluid samples were collected from 10 Holstein 4- to 5-year-old cows in estrus. TPaLP was assessed according to the samples&apos; ability to inhibit rat hepatic microsomal lipid peroxidation, by determination of the 2-thiobarbituric acid reactive material. TPaLP (mean % � SEM) of the BF and BO were 70.63 � 10.03 and 16.33 � 4.33, respectively, whereas those of the IVP [in vitro-matured (IVM), in vitro-fertilized (IVF), and IVC] media were lower (17.94 � 1.66, -1.82 � 0.78, and 14.57 � 1.26, respectively). TPaLP of the 0.1 mM G-modified IVP medium increased to 67.2 � 5.85, 19.98 � 2.49, and 69.19 � 6.22, respectively. A total of 2041 class A oocytes were used. The proportion of cleavage, early embryo development (embryos with more than 4 cells), or both after IVP (18 h IVM–5% CO2 in air, and 18 h IVF, 48 h IVC–5% CO2, 10% O2, 85% N) in the presence of G (n = 1237) during each of the IVP phases or any possible combination of IVP phases was compared with the respective control (C, n = 804). Statistical analysis was performed by a chi-squared test; P &lt; 0.05 was considered significant. G improved cleavage and embryo development rates when present during IVM (79.4 and 57.8% vs. 64.5 and 38.2% for C) or both IVM and IVC (78.0 and 60.7% vs. 57.8 and 36.5%, respectively). When present only during 18 h of IVF, G had no effect on embryo production. However, an increased embryo development rate resulted from the combined exposure to G during IVF and IVM (56.4 vs. 29.6%), during IVF and IVC (55.3 vs. 35.5%), or at all IVP phases (56.6 vs. 34.9%). The latter effect resembled the one obtained after G addition only to the IVC medium (62.5 vs. 39.7%, respectively). We concluded that the addition of G to IVP substrates, at concentrations that mimic the in vivo TPaLP conditions, could promote bovine IVP efficiency.

Cardiac force and high-energy phosphates under metabolic inhibition in four ectothermic vertebrates

1996 ◽  
Vol 271 (4) ◽  
pp. R946-R954 ◽  
Author(s):  
T. Hartmund ◽  
H. Gesser
Keyword(s):  
Creatine Kinase ◽  
Atpase Activity ◽  
Kinase Activity ◽  
Energy State ◽  
High Energy ◽  
Creatine Kinase Activity ◽  
The Other ◽  
Freshwater Turtle ◽  
High Energy Phosphates ◽  
Isometric Twitch

Isometric twitch tension of ventricular preparations stimulated at 0.2 Hz fell over 30 min of anoxia by a fraction decreasing in the order rainbow trout, cod, eel, and freshwater turtle. Drops in the estimated cytoplasmic energy state were related to larger tension losses for trout than for the other species, possibly due to larger changes in free phosphate. Anoxic energy degradation was slower for turtle than for the other species. Anoxia combined with glycolytic inhibition (1 mmol/l iodoacetate) enhanced the decrease in twitch tension for a drop in energy state and enlarged the increase in ADP/ATP relative to that in creatine/phosphocreatine to an extent inversely related to the creatine kinase activity. Furthermore, it increased resting tension to an extent possibly related to myosin-adenosinetriphosphatase (ATPase) activity and lowered the content of phosphorylated adenylates in trout and turtle myocardium. The results indicate that species differences in performance of the metabolically challenged myocardium depend on energy-degrading processes, e.g., myosin-ATPase activity, phosphate release, creatine kinase activity, and efflux/degradation of ADP and AMP, and that glycolysis offers protection due to its cytoplasmic localization.

Differential effect of metabolic fuels on the energy state and Na(+)-K(+)-ATPase in isolated cerebral microvessels

1993 ◽  
Vol 265 (5) ◽  
pp. E777-E782
Author(s):  
I. Sussman ◽  
V. Schultz ◽  
S. Gupta ◽  
C. Grady ◽  
N. B. Ruderman ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Atpase Activity ◽  
Acid Metabolism ◽  
Energy State ◽  
Acid Oxidation ◽  
Free Medium ◽  
Cerebral Microvessels ◽  
Endogenous Fatty Acid ◽  
Atp Generation ◽  
Beta Hydroxybutyrate

Isolated bovine cerebral microvessels (ICMV) were incubated with different metabolic fuels to determine their ability to support microvessel Na(+)-K(+)-ATPase (quantitated as ouabain-sensitive 86Rb+ uptake) and the ATP/ADP ratio. In comparison with ICMV incubated with glucose, Na(+)-K(+)-ATPase activity was reduced by 55% after a 3-h incubation in fuel-free medium and by 30-40% after incubation with beta-hydroxybutyrate, acetoacetate, or glutamate. However, Na(+)-K(+)-ATPase activity was not significantly decreased in ICMV incubated with pyruvate or oleate plus carnitine. In contrast, only glucose was able to maintain the ATP/ADP ratio. To evaluate the effect of endogenous fatty acid metabolism on these parameters, ICMV were incubated with bromostearate, an inhibitor of fatty acid oxidation. Bromostearate decreased both Na(+)-K(+)-ATPase activity and the ATP/ADP ratio, even in the presence of glucose. These results indicate that the varying effects of different fuels on Na(+)-K(+)-ATPase in ICMV cannot be explained solely by their effects on the ATP/ADP ratio or on glycolytic ATP generation. They suggest that other fuel-modulated factors play a key role in regulating this enzyme.

scholarly journals Influence of Carbamazepine Dihydrate on the Preparation of Amorphous Solid Dispersions by Hot Melt Extrusion

Pharmaceutics ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 379 ◽  
Author(s):  
Xiangyu Ma ◽  
Felix Müller ◽  
Siyuan Huang ◽  
Michael Lowinger ◽  
Xu Liu ◽  
...  
Keyword(s):  
Energy State ◽  
Solid Dispersions ◽  
Amorphous Solid ◽  
Hot Melt Extrusion ◽  
Water Soluble ◽  
Melt Extrusion ◽  
Amorphous Solid Dispersions ◽  
Water Soluble Drugs ◽  
The Impact ◽  
Hot Melt

Amorphous solid dispersions (ASDs) are commonly used in the pharmaceutical industry to improve the dissolution and bioavailability of poorly water-soluble drugs. Hot melt extrusion (HME) has been employed to prepare ASD based products. However, due to the narrow processing window of HME, ASDs are normally obtained with high processing temperatures and mechanical stress. Interestingly, one-third of pharmaceutical compounds reportedly exist in hydrate forms. In this study, we selected carbamazepine (CBZ) dihydrate to investigate its solid-state changes during the dehydration process and the impact of the dehydration on the preparation of CBZ ASDs using a Leistritz micro-18 extruder. Various characterization techniques were used to study the dehydration kinetics of CBZ dihydrate under different conditions. We designed the extrusion runs and demonstrated that: 1) the dehydration of CBZ dihydrate resulted in a disordered state of the drug molecule; 2) the resulted higher energy state CBZ facilitated the drug solubilization and mixing with the polymer matrix during the HME process, which significantly decreased the required extrusion temperature from 140 to 60 °C for CBZ ASDs manufacturing compared to directly processing anhydrous crystalline CBZ. This work illustrated that the proper utilization of drug hydrates can significantly improve the processability of HME for preparing ASDs.

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