Spermine/nitric oxide complex (
Sper/NO) is a new
nitric oxide (NO) donor with a long half-life providing controlled
biological release of NO in vivo. The purpose of this study was to determine whether flap survival could be improved by pre-ischaemic or post-ischaemic
intravenous administration of
Sper/NO. We divided 37 male Wistar rats into four experimental groups. An extended epigastric adipocutaneous flap was raised in each animal. The mean area of flap
necrosis was assessed for all groups on the fifth postoperative day, using planimetry software. The average area of flap
necrosis was mean +/- s.d. = 68.2%+/-18.1% in the control group, and 29.7% +/- 13.3% in the non-ischaemic controls. The group with pre-ischaemic application of
Sper/NO demonstrated an average flap
necrosis of mean+/-s.d. = 11.2%+/-5.9%, whereas this increased to 59.2%+/-14.4% in the group receiving
Sper/NO 5 min prior to reperfusion. The group with pre-ischaemic application of
Sper/NO showed a significantly lower area of flap
necrosis than either of the control groups or the group receiving
Sper/NO just prior to reperfusion (P < 0.05). The group receiving
Sper/NO just prior to reperfusion demonstrated a significantly higher mean area of flap
necrosis than the non-ischaemic controls (P < 0.05), but did not differ significantly from the control group. Our data show that pharmacological preconditioning and enhancement of flap survival can be achieved by
intravenous administration of
Sper/NO. The application of
Sper/NO at the end of the ischaemia period or in the early reperfusion period provides no protection against ischaemia-
reperfusion injury.