Millimeter microwave effect on ion transport across lipid bilayer membranes.
The effects of millimeter microwaves in the frequency range of 54-76 GHz on capacitance and conductance of lipid bilayer membranes (BLM) were studied. Some of the membranes were modified by gramicidin A and amphotericin B or by tetraphenylboron anions (TPhB-). The millimeter microwaves were pulse-modulated (PW) at repetition rates ranging from 1 to 100 pps, PW at 1000 pps, or unmodulated continuous waves (CW). The maximum output power at the waveguide outlet was 20 mW. It was found that CW irradiation decreased the unmodified BLM capacitance by 1.2% +/- 0.5%. At the same time, membrane current induced by TPhB- transport increased by 5% +/- 1%. The changes in conductance of ionic channels formed by gramicidin A and amphotericin B were small (0.6% +/- 0.4%). No "resonance-like" effects of mm-wave irradiation on membrane capacitance, ionic channel currents, or TPhB- transport were detected. All changes in membrane capacitance and currents were independent of the modulation employed and were equivalent to heating by approximately 1.1 degrees C.
Alekseev
S I
SI
Institute of Cell Biophysics, Russian Academy of Sciences, Pushchino, Moscow Region.
Ziskin
M C
MC
D000666:Amphotericin B / Q000494:pharmacology; D002784:Cholesterol / Q000737:chemistry / Q000528:radiation effects; D004553:Electric Conductivity; D006096:Gramicidin / Q000494:pharmacology; D006358:Hot Temperature; D007473:Ion Channels / Q000187:drug effects / Q000528:radiation effects; D017136:Ion Transport / Q000187:drug effects / Q000528:radiation effects*; D008051:Lipid Bilayers / Q000737:chemistry / Q000528:radiation effects*; D008563:Membrane Lipids / Q000737:chemistry / Q000528:radiation effects*; D008564:Membrane Potentials / Q000187:drug effects / Q000528:radiation effects; D008872:Microwaves; D010713:Phosphatidylcholines / Q000737:chemistry / Q000528:radiation effects; D013775:Tetraphenylborate / Q000493:pharmacokinetics / Q000494:pharmacology
D007473:Ion Channels; D008051:Lipid Bilayers; D008563:Membrane Lipids; D010713:Phosphatidylcholines; D006096:Gramicidin; D013775:Tetraphenylborate; D000666:Amphotericin B; D002784:Cholesterol