The flux distribution within ischemic ulcers and adjacent skin and its change by prostanoids was investigated using laser Doppler flux scanning. A prostanoid-induced increase in ulcer flux could be a rationale for the improved wound healing. In a single-blind prospective study 18 patients received prostaglandin E1 (PGE1) (333.3 ng/min.), iloprost (41.7 ng/min final dose), and 0.9% saline in a randomized order. The average laser Doppler flux within the ulcer (LFU, x +/- SEM, arbitrary units) or in the adjacent skin (LFS) was evaluated before and 30, 60, 90, and 120 min after prostanoid/saline infusion. LFU increased with PGE1 from 2.30 +/- 0.27 to 3.08 +/- 0.31 (+33.9%; P < 0.001) and with iloprost from 2.37 +/- 0.26 to 3.03 +/- 0.27 (+27.8%; P < 0.001) after 120 min, respectively. Saline did not change LFU significantly: 2.19 +/- 0.18 vs 2.55 +/- 0.26 (+16.4%; P > 0.05). Simultaneously, LFS was not significantly changed when pretreatment values were compared with mean flux at 120 min: PGE1 2.13 +/- 0.27 vs 2.54 +/- 0.34, iloprost 2.03 +/- 0.26 vs 1.94 +/- 0.21, and saline 1.74 +/- 0.27 vs 1.92 +/- 0.30 (P > 0.05, each), respectively. The laser Doppler flux scanning technique might be a tool to study the distribution of laser Doppler flux within ischemic ulcers. This might be useful to study the physiological or pathophysiological control of flux within ischemic ulcers as well as possible therapeutic approaches.