Human Erythrocyte Membrane Permeability and Nitroxyl Spin-Label Reduction

Eriksson, Ulf G.; Tozer, Thomas N.; Sosnovsky, George; Lukszo, Jan; Brasch, Robert C.

doi:10.1002/jps.2600750404

Cited by 40 publications

(20 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition, the legitimacy of using the glycerol calibration is successfully confirmed with the average deviation between the two methods 1.5 _+ 0.5%. Red cells contain spin probe reducing components (Eriksson et al, 1986). We commonly observe a decay time of 40-60 min which introduces a fractional error of less than 1% in the volume measurement as long as readings are taken within 1-2 min of mixing.…”

Section: Signal Vs Hematocritmentioning

confidence: 99%

ESR measurement of time-dependent and equilibrium volumes in red cells

et al. 1990

View full text Add to dashboard Cite

Red cell water volumes were measured using ESR methods during transient osmotic perturbation, and under equilibrium conditions. Cell water contents were determined using the spin label Tempone (2,2,6,6-tetramethyl piperidine-N-oxyl) and the membrane impermeable quencher potassium chromium oxalate. With appropriate corrections for intracellular viscosity and changes in cavity sensitivity, equilibrium cell water measured both by electron spin resonance (ESR) and wet minus dry weight methods gave excellent agreement in solutions from 243-907 mOsm. Intracellular viscosities determined from the Tempone correlation times in the same cells gave values ranging from 9-47 centipoise at 21 degrees C. Osmotically induced transient volume changes were measured using Tempone and an ESR stopped-flow configuration. The Tempone response time was estimated at 17 msec compared to 250-350 msec for normal water relaxations. Nonlinear least square solutions to the Kedem-Katchalsky equations including a correction for the finite Tempone permeability gave 0.029 and 0.030 cm/sec for the osmotic permeability of RBCs in swell and shrink experiments, respectively. In stopped-flow experiments accurate water flux data are obtained very soon after challenging cells and do not require baseline subtractions. These results represent significant improvements over conventional light scattering techniques which necessitate corrections for long lasting optical artifacts (200-300 msec), and baseline drifts.

show abstract

Section: Signal Vs Hematocritmentioning

confidence: 99%

ESR measurement of time-dependent and equilibrium volumes in red cells

et al. 1990

View full text Add to dashboard Cite

show abstract

“…The partition coefficients (Po/w) were determined by the ESR spectra of nitroxyl probes in n-octanol and in phosphate-buffered saline as reported previously (Eriksson et al, 1986;Takeshita et al, 1999;Sano et al, 2000 In Vivo ROS Generation in NSAID Ulcer…”

Section: Table 1 Structures and Po/w Of Typical Nitroxyl Probesmentioning

confidence: 99%

“…6). On the other hand, the signal-decay rate of a carboxy-TEMPO probe, which is membrane-impermeable [Po/w: 0.019 (Eriksson et al, 1986)], showed minimal enhancement, and the enhancing ratio was 1.3. The signal-decay rate of a trimethylammonium-TEMPO probe, which has the lowest membrane permeability of the probes used in the experiments [Po/w: 0.0033 (Takeshita et al, 1999)], did not cause the enhanced signal decay (Fig.…”

mentioning

confidence: 99%

Noninvasive Mapping of Reactive Oxygen Species by in Vivo Electron Spin Resonance Spectroscopy in Indomethacin-Induced Gastric Ulcers in Rats

Utsumi¹,

Yasukawa²,

Soeda³

et al. 2005

J Pharmacol Exp Ther

View full text Add to dashboard Cite

Reactive oxygen species (ROS) are thought to be involved in the gastric ulcer formation induced by indomethacin, a typical nonsteroidal anti-inflammatory drug. However, the location and the time course of ROS generation remain unknown. To assess the sites of ROS generation, we applied the noninvasive measurement of ROS to indomethacin-treated rats. By giving orally a membrane-permeable or impermeable probe, the spectra were collected as a function of time by in vivo 300-MHz electron spin resonance (ESR) spectroscopy. The ESR signal-decay rates of membrane-permeable probes, hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO) and 3-methoxycarbonyl-2,2,5,5-tetramethyl-pyrrolidine-1-oxyl, in the gastric mucosal region were significantly enhanced 1 h after indomethacin treatment, and they both caused the protection of ulcer formation; however, membrane-impermeable probes, carboxy-and trimethylammonium-TEMPO, which did not exhibit the enhanced signal decay, had no effect on ulcer formation. The enhanced signal decay in the gastric mucosa was suppressed by coadministration of the antioxidants tiron or dimethylthiourea with the nitroxyl probe. The results suggest that the enhanced signal-decay rates in the gastric ulcers observed by in vivo ESR are associated with protective effects. The enhanced signal decay caused by ROS generation in stomach, contributing to the ulcer formation induced by indomethacin, is also suggested to occur at the gastric mucus layer or the interface or the intracellular compartment of epithelial cells. Overall, these results show the potentials of noninvasive assessment of ROS production and the sites of damage by in vivo ESR using nitroxyl probes directed to specific subcellular regions.Nonsteroidal anti-inflammatory drugs (NSAIDs) have defervescence, analgesia, and anti-inflammatory effects, and their clinical applications to rheumatism, osteoporosis, and osteoarthritis have been increasing. Indomethacin ([1-(4-chlorobenzoyl)-5-methoxy-2-methyl-1H-indol-3-yl] acetic acid) is one of the most widely used NSAIDs in the world because the anti-inflammatory effect of indomethacin on carrageenin-induced edema is approximately 30 times higher than that of aspirin (2-acetoxybenzoic acid) (Winter et al., 1963). NSAIDs cause therapeutic effects by the suppression of prostaglandin biosynthesis via the inhibition of cyclooxygenase (COX) gene expression. This class of agents is also known to cause significant gastrointestinal damage (Vane, 1971). It is known that the COX enzymes have isozymes of three types (Chandrasekharan et al., 2002), and the inhibition of COX-1 in gastric mucosa has been thought to be related with the gastric ulcer formation induced by NSAIDs (Wallace et al., 1998), because COX-1 is involved in maintaining the integrity of gastric mucosa, the increment of

show abstract

“…30 Different concentrations (0.0-1.0 M) of the broadening agent were added to the buffer during preparation of liposomes so it was present in the aqueous polar phase both inside and outside the vesicles. The ferricyanide broadens the EPR signal of AA-SL due to the Heisenberg exchange interaction 31 and does not influence the EPR signal coming from AA-SL located deeply in the lipid bilayer.…”

Section: Localization Of Aa-sl In a Liposome Suspensionsmentioning

confidence: 99%

Partitioning and Localization of Spin-Labeled Amantadine in Lipid Bilayers: An Epr Study

Subczynski¹,

Wojas²,

Pezeshk³

et al. 1998

Journal of Pharmaceutical Sciences

View full text Add to dashboard Cite

EPR was used to study the distribution of the spin-labeled amantadine (AA-SL) between the bulk hydrophobic-hydrocarbon solvent, light paraffin oil, and water and between hydrophobic-hydrocarbon chain region of lipid membranes and water. The AA-SL molecules were soluble in both hydrophobic and polar regions of investigated systems. It was shown that the partition coefficient of AA-SL between the hydrocarbon region of the L-alpha-dimyristoylphosphatidylcholine fluid-phase membrane and water is much higher than between bulk hydrocarbon solvent and water. Furthermore, the partitioning of AA-SL into membranes of multilamellar liposomes made of L-alpha-dimyristoylphosphatidylcholine, L-alpha-dipalmitoylphosphatidylcholine, and L-alpha-distearoylphosphatidylcholine was studied as a function of temperature, indicating no abrupt change at the main phase transition of these membranes. It is also clear from our data that AA-SL can penetrate into the gel-phase membrane practically with the same partitioning as into the fluid-phase membrane. Furthermore, it was shown that at least part of the AA-SL molecule is deeply buried in the hydrocarbon chain region of the membrane.

show abstract

Human Erythrocyte Membrane Permeability and Nitroxyl Spin-Label Reduction

Cited by 40 publications

References 23 publications

ESR measurement of time-dependent and equilibrium volumes in red cells

ESR measurement of time-dependent and equilibrium volumes in red cells

Noninvasive Mapping of Reactive Oxygen Species by in Vivo Electron Spin Resonance Spectroscopy in Indomethacin-Induced Gastric Ulcers in Rats

Partitioning and Localization of Spin-Labeled Amantadine in Lipid Bilayers: An Epr Study

Contact Info

Product

Resources

About