Vascular reactions during electrical stimulation. Vital microscopy of the hamster cheek pouch and the rabbit tibia

Vital microscopy during electrical stimulation was performed in the hamster cheek pouch and the rabbit tibia. Stimulation with DC of 5,20 or 50 microA or AC of 20 microA was demonstrated to cause macromolecular capillary leakage as evidenced by FITC-dextran fluorescence and histological demonstration of extravasated white blood cells. It was further demonstrated that the vascular leakage was blocked by administration of indomethacin. Pulsed electromagnetical fields did not visibly affect the vascular permeability within 3 h. As the same DC electrical stimulator has been demonstrated to increase the osteogenic capacity in similar titanium implants in the rabbit tibia, it is suggested that the observation of macromolecular leakage may predict a positive osteogenic response.