Increased survival of experimental skin flaps in rats following treatment with antiadrenergic drugs.

The effect upon the survival of skin flaps of several drugs which affect the adrenergic system was studied in rats. In control animals 41% of the skin flaps had survived seven days after the operation. Reserpine (1 mg/kg) injected intraperitoneally (i.p.) three days and one day before the flap operation increased the surviving flap area by 75% (p less than 0.001) as compared to control rats injected with saline. I.p. injection of guanethidine (5 mg/kg) or bretylium (10 mg/kg) every 12 hours, starting 24 hours before surgery and continued for 5 consecutive days, also increased the surviving flap area (19 and 33% respectively p less than 0.001). The surviving flap area was unchanged when desipramine (5 mg/kg) was injected in the same way and was decreased by 15% (p less than 0.05) following i.p. injection of the MAO inhibitor pheniprazine (5 mg/kg). Treatment with alpha-methyl-p-tyrosine (75 mg/kg), i.p. 30 min before surgery or 6-hydroxydopamine (50 mg/kg) i.v. 24 hours prior to surgery also increased the flap survival (56 and 49% increase in surviving flap area, respectively, p less than 0.001). The results demonstrated that the survival of skin flaps increased when the function of the adrenergic nervous system was inhibited. Enhanced sympathetic nervous activity slightly reduced or did not affect skin flap survival.