Frequency sensitivity of nanosecond pulse EMF on regrowth and hsp70 levels in transected planaria

Abstract

Purpose: To study the effect of time varying/ pulsing electromagnetic fields (PEMF) on bio-logical systems by measuring regrowth and the induction of elevated levels of the stress protein hsp70 in the regenerative model Planaria Duge-sia dorotocethala. Objective: The outcomes of studies using electromagnetic fields (EMF) are dependent on pulse design, field strength (mG), frequency (Hz), duration and magnetic field/rise time (dB/ dt). Standardization of effective pulse design is necessary to avoid continuing confu-sion in the investigation of pulsing electro-magnetic field (PEMF) technology. Information from studies on hsp70 protein induction and regrowth in transected Planaria provides in-formation on EMF efficacy for potential clinical application in the treatment of ischemia reper-fusion injury and the eventual inclusion of EMF prophylaxis prior to surgery. Materials and methods: Planaria were transected equidistant between the tip of the head and the tip of the tail. Individual head and tail portions from the same worm were placed in pond water and exposed to 8, 16 or 72 Hertz PEMF for one hour daily post transection under carefully controlled exposure conditions. Regrowth of heads and tails was measured in PEMF-exposed and sham control. Protein lysates from PEMF-exposed and sham control transected heads and tails were ana-lyzed for hsp70 levels by Wes￥tern blot analy-ses. Conclusion: The degree of regrowth and hsp70 levels in transected heads and tails ex-posed to nanosecond PEMF exposures at 8, 16 or 72 Hz was frequency dependent. There are currently several views on the interaction mechanism involved in regrowth. Here we dis-cuss two: in one [7,8] we propose a direct effect on the DNA of the PEMF consensus sequence, nCTCTn, referred to as electromagnetic field response elements (EMRE) in the promoter re-gion of the stress response gene HSP70. In the second mechanism [28] it is proposed that EMF induce vibrations of proteins through a series of quantized low frequency phonon signals

Optimal durations of single exposures to a frequency‐modulated magnetic field immediately after bisection in planarian predict final growth values

“…Different amplitudes (as low as 40 nT) and frequencies (1, 3, 7, 32, and 60 Hz) exhibited stimulatory capacity while others did not. Madkan et al [] also reported differential rates for growth, depending upon the employed frequencies (8, 16, and 72 Hz) in planarian exposed after transection to nanosecond pulsing electromagnetic fields (EMFs) for 1 h daily. There was a general increase in heat shock protein (hsp) 70 in the tail portions of the segments when they were exposed to any of the three frequencies and durations between 20 and 80 min [Madkan et al, ].…”

“…Madkan et al [] also reported differential rates for growth, depending upon the employed frequencies (8, 16, and 72 Hz) in planarian exposed after transection to nanosecond pulsing electromagnetic fields (EMFs) for 1 h daily. There was a general increase in heat shock protein (hsp) 70 in the tail portions of the segments when they were exposed to any of the three frequencies and durations between 20 and 80 min [Madkan et al, ]. Goodman et al [] confirmed that exposure for 1 h twice per day to 60 Hz, 8 µT magnetic fields during the initial 3 days post‐surgery caused increased regeneration.…”