Effectiveness and toxicity of several DTPA broadening agents for biological ESR spectroscopy.
The effectiveness of a standard ESR broadening agent, potassium trioxalatochromiate (CrOx), for use with the spin-label tempone, was compared to that of diethylenetriaminepentaacetic acid (DTPA) containing an ion (Gd, Cr, Mn, Fe) with a large magnetic moment. Signal attenuation, line broadening, toxicity, and cell membrane permeability were compared. As a broadening agent, CrOx was most effective, followed by Fe-DTPA. CrOx proved mildly toxic while Gd-DTPA and Fe-DTPA were virtually non-toxic. The human red blood cell membrane was tested for permeability to Fe- and Gd-DTPA and found to be impermeable to both. In situations where toxicity to cells is critical, the DTPA chelates, particularly Fe-DTPA, may prove an acceptable substitute for CrOx.
Zaplatin
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Department of Physics, IUPUI, Indianapolis, Indiana 46202, USA.
Baker
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Kleinhans
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D002470:Cell Survival / Q000187:drug effects*; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D004910:Erythrocyte Membrane / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D009994:Osmolar Concentration; D004369:Pentetic Acid / Q000493:pharmacokinetics / Q000633:toxicity*; D013081:Sperm Motility / Q000187:drug effects; D013113:Spin Labels; D013329:Structure-Activity Relationship
D013113:Spin Labels; D004369:Pentetic Acid