Search results for: 2-(Aminomethyl)-2-methyl Doxyl C7H15N2O2 CAS: 663610-75-1
#16572921 // To Up
Mononuclear cell membranes: stabilization by reproterol and cromoglycate, destabilization by fenoterol and salbutamol.
Electron paramagnetic resonance (EPR) spectroscopy with spin labels 5- and 16-doxyl-stearic acid (DSA) was used to differentiate between actions of beta-agonists on human mononuclear cell membrane. Reproterol (CAS 13055-82-8), salbutamol (CAS 51022-70-9) and fenoterol (CAS 1944-12-3) compared to cromoglycate (CAS 15826-37-6) were used at concentrations of 10-100 nmol/l per 10(7) cells. With reproterol, order and polarity was not much changed, whereas salbutamol and fenoterol significantly destabilized the membrane to similar extent. Cromoglycate acted in a stabilizing fashion. With trypan blue exclusion, reproterol and cromoglycate showed stable values, whereas salbutamol and fenoterol augmented permeability. Thus, by conventional lipid spin labeling the discrimination between salbutamol and fenoterol could not be carried out. In contrast, previous lipid peroxidation studies in a model system had revealed a decrease by reproterol, no change by salbutamol and an increase by fenoterol. Also, using fenoterol, protein spin label 4-maleimido-TEMPO (2, 2, 6, 6-tetramethyl-1-piperidinyloxy) showed an increase of membrane rigidity of mononuclear cells. Moreover, mast cells of different origin were previously found tween beta-agonists. Reproterol in all tests behaved in a therapeutically profitable way. In conclusion, in addition to lipid spin labeling other methods and materials should be considered, to finally arrive at a more realistic differentiation between, for instance, salbutamol and fenoterol. The term "membrane (de) stabilization" should not generally be used without careful consideration of the type of cell/membrane in question.Guido Zimmer, Markus Bernhörster, Patrizius Pilz, Jutta Schuchmann-Fix, Rolf Hüggelmeier, Nicole Blüm, Herman Libertus
1272 related Products with: Mononuclear cell membranes: stabilization by reproterol and cromoglycate, destabilization by fenoterol and salbutamol.
10 mg10 mg100 mg1,000 tests1000 1 mg1 ml100ug100ul25 mg1000 testsRelated Pathways
#9125277 // To Up
Interaction of glucose and metformin with isolated red cell membrane.
Isolated human erythrocyte membranes (red blood cell (RBC) ghosts) were incubated with glucose at 5, 10, 20 and 100 mmol/l concentrations, with insulin (0.01 to 200 mU/l) and metformin (CAS 657-24-9) 0.5 up to 50.0 mumol/l). Binding studies with 14C-glucose and subsequent gel electrophoresis revealed 60% of the radioactivity around ban 4.2-4.5 at 5 mmol/l, whereas a random distribution of radioactivity over all protein bands of the RBC membrane was found at 20 mmol/l concentration after incubation for 30 min or 48 h. Metformin does not bind covalently to RBC membranes, however, after photochemical linkage of 14C-metformin via the aminoreactive linker azidophenylglyoxal the highest radioactivity (21%) was counted in the range of band 4.2-4.5. In parallel with an increase of order parameters of 5-doxyl-stearic acid the thiol status of the membranes decreases as determined by monobromobimane fluorescence. 20 and 100 mmol/l concentrations of glucose decrease the reactivity of membrane thiols towards bromobimane significantly to 73 and 62% of the controls. Concomitantly, membrane fluidity at polar sites is diminished as measured by order parameters of spin label 5-doxyl stearic acid. In RBC membranes pretreated with 20 mmol/l glucose the decreased fluorescence is significantly raised again by insulin and metformin. This effect is even more pronounced, if insulin and metformin are incubated together. Reaction of membrane thiols with a maleimido spin label detects modification in the ratio of mobile and immobilized spin label populations in the electron paramagnetic resonance signal under the above conditions, indicative of conformational changes of membrane proteins.H J Freisleben, H J Fürstenberger, S Deisinger, K B Freisleben, N Wiernsperger, G Zimmer
2159 related Products with: Interaction of glucose and metformin with isolated red cell membrane.
100 ml. 1KG1 kit25 ml.1 kit96 assays1.00 flask1 kitRelated Pathways
#8387787 // To Up
Effects on heart membranes after taurine treatment in rabbits with congestive heart failure.
Oral treatment with taurine (CAS 107-35-7) of rabbits with congestive heart failure (CHF) caused by impairment of aortic valve dose-dependently improved hemodynamic and contractile indices of the heart and prolonged the animals' life. Analysis of heart membrane fraction of CHF animals, using a paramagnetic probe 4-tempo-stearamide, demonstrated a loss of negative charge of the membranes. In vitro addition of taurine had no effect on the charge of phospholipid heads. The use of a 5-doxyl-stearate probe revealed that membrane fluidity decreased with the development of CHF as compared with normal membranes. Taurine increased membrane fluidity in animals with CHF, but did not affect membranes isolated from animals with CHF which had undergone taurine treatment and elevated membrane rigidity in the control group.E P Elizarova, T R Orlova, N V Medvedeva
1841 related Products with: Effects on heart membranes after taurine treatment in rabbits with congestive heart failure.
100 UG4 Membranes/Box1 ml4 Membranes/Box50 µg4 Membranes/Box4 Membranes/Box4 Membranes/BoxRelated Pathways
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