Enzymatic responses to skin flap elevation following a delay procedure

Alterations in enzyme activities of glucose metabolism were determined in the distal portion of the skin flaps of guinea pigs elevated following 3, 7, 14, or 21 days of the delay period. Hexokinase, pyruvate kinase, lactate dehydrogenase, and glucose 6-phosphate dehydrogenase activities were increased during the delay period, whereas isocitrate and malate dehydrogenases exhibited little alteration. Increases in glycolytic enzyme activities observed during the delay procedure were diminished in the flaps elevated during initial 3 days of the delay period, but were maintained or increased further in the flaps elevated at 7 to 21 days. Despite high levels of enzyme activities during the early period of the delay, the flaps elevated during this period exhibited partial necrosis with a low glucose level and decreased enzyme activities. It is concluded that tissue glucose level and its utilization are crucial factors for flap survival.