title: Cellulr restitution after 3 h of complete tourniquet ischemia.
abstract: The refinement of techniques for extremity surgery makes it urgent to get more information at cell level of the effects of tourniquet times exceeding the usually accepted 90--120 min. Therefore, in the present experiments, the cellular metabolic and functional restitution of canine skeletal muscle after 3 h of complete tourniquet ischemia was studied. During the ischemia and after recirculation, repeated skeletal muscle samples were taken for ATP, CP and lactate analyses. At the same time periods, blood from a regional vein and vena cava was drawn for pH, pyruvate and lactate analyses. Cellular function was evaluated from repeated measurements of transmembrane potentials. The tourniquet ischemia resulted in a rapid decrease of CP to 40% of the initial level within 1 h and a continuous decrease of ATP. The lactate levels increased continuously. The transmembrane potentials decreased from an initial level of --90 to --54 mV. The release of the tourniquet resulted in a hyperemic reaction and a rapid regain of tissue CP and ATP levels within 5 min of recirculation. There was a continuous washout of lactate up to about 1 h after the release and the transmembrane potentials were normalized after about the same time period. The latter parameters indicate that areas of no-reflow persisted for up to 1 h after restored circulation. The results indicate that after a 3-hour tourniquet ischema, the cellular energy metabolism as well as the membrane function are completely normalized after about 1 h of recirculation.
mesh_terms: D000255:Adenosine Triphosphate / Q000032:analysis; D000818:Animals; D004285:Dogs; D005121:Extremities / Q000098:blood supply*; D007511:Ischemia / Q000097:blood / Q000503:physiopathology*; D007773:Lactates / Q000032:analysis; D008564:Membrane Potentials; D009132:Muscles / Q000032:analysis / Q000098:blood supply / Q000503:physiopathology*; D010725:Phosphocreatine / Q000032:analysis; D014111:Tourniquets
chemical_list: D007773:Lactates; D010725:Phosphocreatine; D000255:Adenosine Triphosphate