Medical/biological study (experimental study)

Myocardial function improved by electromagnetic field induction of stress protein hsp70 med./bio.

By: George I, Geddis MS, Lill Z, Lin H, Gomez T, Blank M, Oz MC, Goodman R

Published in: J Cell Physiol 2008; 216 (3): 816-823

Aim of study (acc. to author)

To examine whether pre-treatment with electromagnetic-field induced levels of stress protein hsp70 can preserve myocardial function after ischemia and re-perfusion.

Background/further details

Studies on myocardial function have shown that hsp70, stimulated by an increase in temperature, leads to improved survival following ischemia and re-perfusion. Male rats were randomly assigned to a control group (n=10) and to an exposure group (n=10), that was irradiated to electromagnetic fields for 30 min prior to ischemia and re-perfusion. Ischemia was induced by ligation of left anterior descending coronary artery for 30 min, followed by 30 min re-perfusion.

Endpoint

molecular biosynthesis: blood and heart tissue levels for hsp70
effects on the cardiovascular system: haemodynamics

Exposure

- 50/60 Hz
- magnetic field

Exposure	Parameters
Exposure 1: 60 Hz Exposure duration: continuous for 30 min	magnetic flux density: 8 µT

Exposure 1

Main characteristics

Frequency	60 Hz
Type	magnetic field
Exposure duration	continuous for 30 min

Exposure setup

Exposure source	Helmholtz coils
Setup	16 cm x 24 cm plastic exposure cage surrounded by Helmholtz coils; coils consisting of 164 turns of 1.5 inches thick 19 gauge copper wire covered with electrical tape

Parameters

Measurand	Value	Type	Method	Mass	Remarks
magnetic flux density	8 µT	-	measured	-	-

Reference articles

Goodman R et al. (1998): Magnetic field stress induces expression of hsp70
Jin M et al. (1997): Biological and technical variables in myc expression in HL60 cells exposed to 60 Hz electromagnetic fields
Wei LX et al. (1990): Changes in levels of c-myc and histone H2B following exposure of cells to low-frequency sinusoidal electromagnetic fields: evidence for a window effect

Exposed system:

Methods Endpoint/measurement parameters/methodology

molecular biosynthesis: blood and heart tissue levels for hsp70 (Western blot); RNA transcription of HSP70 (RT-PCR)
effects on the cardiovascular system: hemodynamics: end-systolic pressure and end-diastolic pressure to compute cardiac output, arterial elastance and contractile function
thermoregulation: rectal temperature

Investigated system:

isolated bio./chem. substance
DNA/RNA
tissue slices
(->left ventricular heart: ischemic and non-ischemic), blood samples
investigation on living organism

Investigated organ system:

cardiovascular system

Time of investigation:

before exposure
during exposure
after exposure

Main outcome of study (acc. to author)

Significant upregulation of the HSP70 gene and increased hsp70 levels were measured in response to electromagnetic field pre-exposure. Hemodynamics demonstrated significant recovery of systolic contractile function after 30 min of re-perfusion following electromagnetic field exposure. Ventricular diastolic function was markedly improved in electromagnetic field-treated animals.
Non-invasive electromagnetic field induction of hsp70 preserved myocardial function and has the potential to improve tolerance to ischemic injury.

Study character:

medical/biological study
experimental study
full/main study

Study funded by

National Institutes of Health (NIH), Maryland, USA
Robert I. Goodman Fund

Zhang Y et al. (2020): Examination of the Effect of a 50-Hz Electromagnetic Field at 500 μT on Parameters Related With the Cardiovascular System in Rats
Wang Y et al. (2019): Exposure to a 50 Hz magnetic field at 100 µT exerts no DNA damage in cardiomyocytes
Zhou L et al. (2016): The effects of a 50-Hz magnetic field on the cardiovascular system in rats
Villarini M et al. (2013): Brain hsp70 expression and DNA damage in mice exposed to extremely low frequency magnetic fields: a dose-response study
Kurian MV et al. (2012): Enhanced cell survival and diminished apoptotic response to simulated ischemia-reperfusion in H9c2 cells by magnetic field preconditioning
Ronchi R et al. (2004): Effects of broad band electromagnetic fields on HSP70 expression and ischemia-reperfusion in rat hearts
Carmody S et al. (2000): Cytoprotection by electromagnetic field-induced hsp70: a model for clinical application
DiCarlo AL et al. (1999): Myocardial protection conferred by electromagnetic fields
Lin H et al. (1999): A magnetic field-responsive domain in the human HSP70 promoter
Han L et al. (1998): Application of magnetic field-induced heat shock protein 70 for presurgical cytoprotection
Goodman R et al. (1998): Magnetic field stress induces expression of hsp70
Lin H et al. (1998): Myc-mediated transactivation of HSP70 expression following exposure to magnetic fields
Lin H et al. (1997): Electromagnetic field exposure induces rapid, transitory heat shock factor activation in human cells
Goodman R et al. (1994): Increased levels of hsp70 transcripts induced when cells are exposed to low frequency electromagnetic fields
Goodman R et al. (1989): Exposure of human cells to low-frequency electromagnetic fields results in quantitative changes in transcripts