Prostacyclin formation in undelayed and delayed pig flank flaps

Summary A specific 6-keto-prostaglandin PGI₂ radioimmunoassay (R.I.A.) was used to follow tissue prostacyclin formation in a series of acute and delayed pig flaps. Each flap measured 12×5 cm and four white, female ehester pigs, averaging 21 kgs in weight, were used. Flap tissue samples were taken at day 0 (control) 1–8, 10, 14, 17 and 21 using 0.4 mm diameter cork borer. Prostacyclin formation started to rise on day 4 and extended until the 10th day in both types of flaps. The hyperemic circulation that occurred following delay procedure is associated with a rise in prostacyclin production whereas the higher rise in prostacyclin in the undelayed flap is due to the reactive inflammation.