Korean J Physiol Pharmacol.
1997 Oct;1(5):581-589.
Effect of UV irradiation and rebamipide on the blood flow and viability
of rabbit skin flap
- Affiliations
-
- 1Department of Pharmacology, College of Medicine, Yeungnam University, Taegu 705-717, South Korea.
Abstract
-
This study was undertaken to examine the effects of ultraviolet light
(UVL) and rebamipide on the cutaneous blood flow and tissue survival on
rabbit skin flap. In a random bipedicle flap, Laser Doppler Flowmetry
(LDF) was employed to measure the blood flow of flap (BFF). Wound
Margin Strength (WMS) measured by force transducer and Light microscopy
were used for evaluation of tissue viability. Single exposure to UVL
increased the BFF gradually for more than 15 hours, and decreased the
vasoconstrictor effect of intravenous phenylephrine. The UVL-induced
increase in BFF regressed after 18 hours of irradiation, and this
regression was tended to be enhanced by intradermal injection of
L-NAME, a nitric oxide synthase (NOS) inhibitor, but the regression was
significantly reversed by acetylcholine, an endothelial constitutive
NOS (cNOS) activator and L-arginine, an NO precursor. Rebamipide, a
novel antiulcer oxide synthase (NOS) inhibitor, but the regression was
significantly reversed by acetylcholine, an endoagent known to
scavenge the hydroxyl radical, abruptly reversed the spontaneous
regression of the UVL-induced increase in BFF by the same manner as
L-arginine. In ischemic skin flap, rebamipide increased the BFF
abruptly by the same manner as sodium nitroprusside (SNP), an NO doner,
while N-acetylcystein (NAC), a free radical scavenger, gradually
increase the BFF. The rebamipide-induced increase in BFF was sustained
at the level of the SNP-induced increase in BFF during the late period
of experiment. Rebamipide increased the WMS of skin flaps and prevented
the tissue necrosis in comparison with L-NAME. Based on these results,
it is concluded that in rabbit skin, UVL irradiation increases the BFF
by NO release, and rebamipide exerts a protective effect on the
viability of ischemic skin flaps by either or both the increase in BFF
by NO release and free radical scavenger effect.