Effects of lumbar sympathectomy on the properties of both endothelium and smooth muscle cells of the canine femoral artery and autogenous vein grafts under poor runoff conditions.
The purpose of this study was to determine whether or not a lumbar sympathectomy would modulate the functions of the endothelium, in terms of endothelium-derived relaxing factor (EDRF), under poor distal runoff conditions. First, a poor distal runoff model was developed in the canine right and left femoral arteries. After 5 weeks, a unilateral left sympathectomy was performed from L-3 to L-6. In experiment I, changes in blood flow and endothelium-dependent responses were examined in the canine femoral artery 5 weeks after the lumbar sympathectomy. In experiment II, 5 weeks after the development of a poor runoff model, a unilateral left sympathectomy was performed and both femoral veins were also grafted to the femoral arteries on both sides. Then after 4 weeks, endothelium-dependent responses and intimal thickening of both autogenous vein grafts were examined. The endothelium-dependent responses were examined by mechanical tension recording. In both experiments, the mean blood flow of the left femoral arteries (denervated, 92.2 +/- 47.1 ml/min) and vein grafts (denervated, 100.0 +/- 35.4 ml/min) was significantly higher than that of the right femoral arteries (innervated, 46.9 +/-25.7 ml/min) and vein grafts (innervated, 50.0 +/- 20.1 ml/min) (P < 0.01). In experiment I, the endothelium-dependent relaxations to acetylcholine, ADP, and A23187 were comparable between the right and left femoral arteries. In experiment II, the endothelium-independent contractions to acetylcholine and endothelium-dependent relaxations to ADP and A23187 were all comparable between the right and left vein grafts. In addition, the intimal thickening of the vein graft was comparable between the two groups (denervated, 95.6 +/- 10.8 microm; innervated, 105.0 +/- 15.0 microm). In both experiments, the NE-induced contractions and SNP-induced relaxations were closely similar between the two groups, irrespective of the flow change. These results suggest that lumbar sympathectomy does not alter endothelial function in terms of EDRF, although mean blood flow of the denervated femoral arteries and vein grafts was significantly higher than that of the innervated femoral arteries and vein grafts. These results suggest that continuous vasodilation following sympathectomy may be a more potent factor with respect to regulation of vascular tonus than physiologic regulation of EDRF.
Funahashi
S
S
Department of Surgery II, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
Komori
K
K
Itoh
H
H
Okadome
K
K
Sugimachi
K
K
D000109:Acetylcholine / Q000494:pharmacology; D000244:Adenosine Diphosphate / Q000494:pharmacology; D000818:Animals; D001783:Blood Flow Velocity / Q000502:physiology; D000001:Calcimycin / Q000494:pharmacology; D004285:Dogs; D004730:Endothelium, Vascular / Q000294:innervation*; D005260:Female; D005263:Femoral Artery / Q000166:cytology / Q000294:innervation*; D008161:Lumbosacral Region / Q000601:surgery; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000294:innervation*; D009569:Nitric Oxide / Q000502:physiology; D009599:Nitroprusside / Q000494:pharmacology; D013562:Sympathectomy; D014182:Transplantation, Autologous; D014664:Vasodilation / Q000502:physiology; D014680:Veins / Q000637:transplantation*
D009599:Nitroprusside; D009569:Nitric Oxide; D000001:Calcimycin; D000244:Adenosine Diphosphate; D000109:Acetylcholine