Effects of pulsed and sinusoidal electromagnetic fields on MMP-2, MMP-9, collagen type IV and E-cadherin expression levels in the rat kidney: an immunohistochemical study.

Objective: To investigate the role of extremely low frequency pulsed and sinusoidal electromagnetic fields on kidney tissues.

Study Design: Twenty-seven male Wistar albino rats were used. The rats were divided into 3 groups (n = 9): control group, sinusoidal electromagnetic field (SEMF) group, and pulsed electromagnetic field (PEMF) group. The SEMF and PEMF groups (pulse time 25 microsn, pulse frequency 50 Hz) were subjected to 1.5 mT, 50 Hz, exposure 6 hours a day, 5 days a week for 28 days in methacrylate boxes. Formalin-fixed, paraffin-embedded kidney tissue sections were stained with hematoxylin-eosin, Gomori and periodic acid-Schiff. In addition, matrix metalloproteinase-2 (MMP-2) and 9 (MMP-9), E-cadherin and collagen type IV expression levels were examined immunohistochemically.

Results: Thickening of glomerular basement membranes was evident in electromagnetic fields, especially in the SEMF group. In addition, expression levels of E-cadherin were decreased with electromagnetic field (EMF) exposure. The expression level of MMP-9 increased, and MMP-2 and collagen type IV expression levels were not altered with EMF exposure.

Conclusion: Both EMFs changed the molecular component of the kidney adversely.