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EMF Study
(Database last updated on Mar 27, 2024)

ID Number 1327
Study Type In Vitro
Model 10 MHz (PW/burst) exposure any analysis of vasodilation in tissues and tissue homogenates
Details

Frog (Xenopus laevis) foot webs were isolated and exposed to 10 MHz (PW) at an E-field of 2.19 V/cm while being maintained at 20 degrees C. Frog (Xenopus laevis) foot webs were isolated and exposed to 10 MHz (PW-50% burst time, 10 kHz burst rate) at an E-field of 2.19 V/cm while being maintained at 20 degrees C. Arterioles became dilated following 60 minutes of exposure, remaining constant and slowly subsiding with additional exposure times. The authors suggest the effect was non-thermal as the field was too weak to have produced enough heat to dilate the arterioles, and heat would have been constantly conducted away by the perfusion solution. The pattern of vasodilatation induced by warm Ringer solution was different from that of the RF radiation. The authors hypothesized that the RF vasodilatory effect was caused by facilitation of Ca2+ outflow, as Ca2+ concentration affected the degree of vasodilation, and it was inhibited by vanadate (an inhibitor of Ca(2+)-ATPase) and abolished by Methylene Blue (an inhibitor of guanylate cyclase) suggesting a mechanism of increased Ca2+ outflow through the plasma membrane of the smooth muscle and/or increase in Ca2+ influx into the sarcoplasmic reticulum. In a related study, rat cerebellum supernatant was exposed to similar RF and examined for cyclic GMP +/- L-arginine (nitric oxide donor) and NADPH (reducing agent). RF exposure plus L-arginine and/or NADPH caused production of cyclic GMP to increase significantly, while chelation with EDTA lowered cyclic GMP production and blocked any RF effect. The authors suggest that RF activates NO synthase to induce vasodilatation.

Findings Effects
Status Completed With Publication
Principal Investigator Gunma University School of Medicine, Maebashi-shi,
Funding Agency Private/Instit.
Country JAPAN
References
  • Miura, M et al. J. Physiol., (1993) 461:513-524
  • Miura, M et al. J. Physiol., (1991) 435:257-273
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