Physiological roles of endothelium-derived nitric oxide in the epigastric island flaps of rabbits.
Nitric oxide (NO), identified as the mediator of endothelium-dependent relaxation of vascular smooth muscle, is known to cause a number of inflammatory conditions, especially in ischemia/reperfusion injury. This experimental study, using a rabbit epigastric island flap, was designed to investigate whether skin flap ischemia followed by reperfusion-influenced serum NO and c-GMP concentrations in the flap. In addition, we also investigated the premedicated effects of the NO synthase inhibitor and heparin on serum NO and c-GMP concentrations in skin flap ischemia/reperfusion. Serum NO concentration after 15, 30, 45, and 60 minutes of ischemia followed by reperfusion significantly increased compared with that in nonischemic control and elevated flaps. On the contrary, serum NO concentration was suppressed in L-NAME or aminoguanidine pretreated animals with ischemic group. Administration of heparin increased the serum NO concentration in elevated flaps, but suppressed it in ischemic flaps followed by reperfusion. The changes in serum c-GMP and NO concentrations were related in all of the experimental groups. These results suggest that NO may be derived from vascular endothelial cells and dilate peripheral vessels in compensation for ischemia.
Oshima
H
H
Department of Plastic and Reconstructive Surgery, St. Marianna University School of Medicine, Kawasaki, Japan.
Inoue
H
H
Aihara
M
M
Tomioka
M
M
Ishida
H
H
D000818:Animals; D006152:Cyclic GMP / Q000378:metabolism; D004730:Endothelium, Vascular / Q000378:metabolism*; D019074:Epigastric Arteries; D006146:Guanidines / Q000494:pharmacology; D006493:Heparin / Q000494:pharmacology; D007511:Ischemia / Q000378:metabolism; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism / Q000502:physiology*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D011817:Rabbits; D015424:Reperfusion; D013524:Surgical Flaps / Q000098:blood supply
D006146:Guanidines; D009569:Nitric Oxide; D006493:Heparin; D019001:Nitric Oxide Synthase; D006152:Cyclic GMP; C004479:pimagedine; D019331:NG-Nitroarginine Methyl Ester