Measurement of blood flow in skin with an intact vascular pedicle

An experimental model was devised to confirm directly the validity of total skin blood flow measurement, as postulated by Sejrsen. A section of skin in the groin of the rat was prepared, which contained an intact artery and vein. Both of these were direct branches of the femoral vessels. When 133Xe was injected intradermally in saline solution, it was demonstrated that a sham isolated vascular pedicle cleared the isotope, and that the clearance was biexpoential, suggesting two compartments. When the vascualr pedicle was ligated, thereby removing direct blood flow to the piece of skin, the 133Xe clearance curve was monexponential. It is concluded that the rapid portion of the biexponential clearance curve, as analyzed by Sejrsen, does represent the dermal vascular components of isotope clearance, and that measurement of cutaneous blood flow by this method is a valid and useful technique. Results using this technique to follow rejection in a new skin transplant model are presented.