Acute difluoromethylornithine treatment increases skin flap survival in rats

Difluoromethylornithine (DFMO) pretreatment for 7 days improved survival of rat abdominal skin flaps in previous studies. The purpose of this study was to determine if acute administration of DFMO enhances survival. Each rat had a 7 x 7-cm abdominal skin flap raised on a single epigastric neurovascular pedicle. Within 1 minute of pedicle ligation, the rats were given 0, 1, or 4 gm/kg of body weight of DFMO intraperitoneally. Putrescine was administered to additional rats alone or with DFMO. After 48 hours, the percentage of flap survival was estimated using fluorescein injection and planimetry to quantify the perfused and unperfused areas. Flap survival increased from 71 +/- 3% in controls to 83 +/- 2% and 92 +/- 3% in rats treated with 1 and 4 gm/kg of DFMO, respectively (p less than 0.005). Putrescine reversed the protective effect of DFMO, suggesting a specific polyamine-related mechanism. This study indicates that there may be both short- and long-term polyamine pools through which DFMO acts. In summary, DFMO may prove to be important in preventing cell death following acute ischemia.