Role of sensory and motor intensity of electrical stimulation on fibroblastic growth factor-2 expression, inflammation, vascularization, and mechanical strength of full-thickness wounds

Electrical stimulation (ES) profoundly affects angiogenesis by modulating the production of angiogenic factors. We evaluated the effect of sensory (direct current, 600 microamperes) and motor (monophasic pulse current, 2.5 to 3 milliamperes, 300-microsecond pulse duration, 100 Hz) intensities of cathodal current on the release of fibroblastic growth factor-2 (FGF-2) at the wound site and also the biomechanical and histological properties of healed skin. Ninety-six male, Sprague-Dawley rats were randomly assigned into one control and two experimental groups. A full-thickness skin incision was made on the dorsal region of each animal. The experimental groups received 10 sessions of ES (sensory or motor) for 1 hour per day every other day. The results showed that FGF-2 levels in the sensory group were significantly greater than in the other groups on the third day. In the motor group, FGF-2 levels were significantly decreased compared with the control group. There were no significant differences between the normalized ultimate strength and stiffness in the groups, but they tended to be higher in the motor ES group. We conclude that the application of sensory ES during the early stage of wound healing may have a beneficial effect on wound healing by inducing the release of angiogenic factors and decreasing the duration of the inflammation phase.