Effects of low-frequency pulsed electromagnetic fields on wound healing in rat skin

ABSTRACT

Pulsed electromagnetic field stimulators are used for promotion of healing in various conditions such as bone, cartilage and ligament injuries, but there are controversies about the use of these stimulators for skin wound healing. The aim of this study was to investigate the effects of different pulse rates of pulsed electromagnetic fields [PEMF] on skin wound healing in rats. Forty-eight male Wistar rats were used in this study. After anaesthetizing and shaving, a paired full thickness incision wound [35 mm in length] was made on each side of the dorsal midline of the rats. The animals were divided into eight groups [n=6] namely control, sham and six treatment groups which were exposed to10, 20, 40, 50, 60, and 80 Hz pulse rates. Treatment groups were exposed to PEMF [4 mT] for 30 minutes twice a day for ten days after surgery. Wound healing was evaluated by measuring the maximum length, the surface area of the wounds and the healing fractions every two-days. The full contraction period of the wounds and the tensile strength of scars were also measured. Results showed that I -The absolute and normalized length of wounds in animals receiving PEMF [20 Hz] were significantly less than that of the sham [P<0.01]. II -The wound healing duration in this group [12.7 days] was significantly shorter than that of the sham group [P<0.02]. III - The wound tensile strength in this group was significantly greater than that of the sham group [P<0.01]. We can conclude that PEMF with 20 Hz pulse rate is effective in promoting of wound healing