Prostacyclin formation in delayed pig flank flaps.

A specific 6-keto-prostaglandin F1 alpha radioimmunoassay was used to follow tissue prostacyclin formation in a series of bipedicle delayed flaps in 2 pigs. Flap tissue samples were taken at intervals for 21 days. Prostacyclin formation started to rise at day 4 and reached a peak at day 7. The increase was statistically significant (p less than 0.05) compared with other days and with the control. This result implies that the increased hemodynamics that occur following the "delay" procedure are effected by prostacyclin, which is a potent humoral factor for vasodilation. The peak of prostacyclin formation one week following surgery correlates well with previous reports demonstrating a maximal blood flow one week after the "delay" procedure.