Comparison of nerve regeneration in vascularized and conventional grafts: nerve electrophysiology, norepinephrine, prostacyclin, malondialdehyde, and the blood-nerve barrier

Abstract

We compared the efficacy of vascularized (VASC) and conventional (CONV) sciatic nerve grafts in restoring nerve blood flow (NBF). conduction, the blood-nerve barrier, norepinephrine (NE), and 6-keto prostaglandin F 1α (6-KPGF; the stable prostacyclin metabolite) in the sciatic nerve of the rat. We also measured malondialdehyde (MDA) content. NBF was much greater in VASC grafts, but the increase was confined to non-nutritive flow. There was a statistically non-significant increase in nerve action potential amplitude in the grafted segments of VASC nerves at 1 and 2 months post graft. The [ 14C]sucrose permeability surface area (PA) product was increased in both CONV and VASC at 1 and 3 months and was not different to each other. NE and 6-KPGF, the major vasoconstrictor and dilator of nerve microvessels were better restored in VASC than CONV reaching statistically significance for 6-KPGF ( P < 0.001). MDA used as an index of oxygen free radical generation was not significantly different in the 3 groups. The better restoration of 6-KPGF and perhaps NE suggest that VASC grafts may be more effective in restoring vasoreactivity of peripheral nerve following graft.