Can electromagnetic radiations induce changes in the kinetics of voltage-dependent ion channels?
Ion channels are protein molecules, which can assume distinct open and closed conformational states, a phenomenon termed ion channel kinetics. The transitions from one state to another depend on the potential energy barrier that separates those two states. Therefore, it is rational to suppose that electromagnetic waves could interact with this barrier and induce changes in the rate transitions of this kinetic process. Our aim is to answer the question: can electromagnetic radiations induce changes in the kinetics of voltage-dependent ion channels? We simulated the effects of the low and high frequency electromagnetic waves on the sodium and potassium channels of the giant axon of Loligo. The key parameter measured was the fractional open time (fv), because it reflects the voltage dependence of the kinetics of channels. The electromagnetic radiations induced the following changes in the kinetics of the potassium and sodium channels: i/ low frequency waves kept the potassium channel 50% of the time open independent on the mean voltage applied through the membrane; ii/ a gradual inhibition of the inactivation on the sodium channel, when the amplitudes of the low frequency waves were increased; iii/ high frequency waves on the potassium channel, decreased both Vo (voltage in which the channel stays 50% open) and the steepness of fv (d fv/dV) as the amplitudes of the waves increased, and iv/ high frequency and low amplitude radiations on the sodium channel decreased the maximum value of fv (in relation to control), while high amplitudes increased this value. In conclusion, high and low frequency electromagnetic radiations were able to change the kinetics of the potassium and sodium channels in a squid giant axon model.
da Costa
Josemar G
JG
Departamento de Biofísica e Radiobiologia, Universidade Federal de Pernambuco, Recife, Brazil.
de Moura
Marco A
MA
Consoni
Luiz
L
Nogueira
Romildo A
RA
D000818:Animals; D001369:Axons / Q000737:chemistry; D049832:Decapodiformes; D007473:Ion Channels / Q000528:radiation effects*; D007700:Kinetics; D018408:Patch-Clamp Techniques; D024642:Potassium Channels, Voltage-Gated / Q000528:radiation effects; D011840:Radiation, Nonionizing; D015222:Sodium Channels / Q000528:radiation effects
D007473:Ion Channels; D024642:Potassium Channels, Voltage-Gated; D015222:Sodium Channels