Similar endothelium-dependent relaxation, but enhanced contractility, of the right gastroepiploic artery as compared with the internal mammary artery.
The right gastroepiploic artery is an alternative coronary bypass graft. The excellent graft function of the internal mammary artery has been related to its physiologic properties, particularly to endothelial function. Isolated artery rings were suspended in organ chambers for recording of isometric tension. Norepinephrine and potassium chloride evoked threefold greater contractions in the gastroepiploic artery than in the mammary artery (p less than 0.01 to 0.05), whereas the sensitivity to the catecholamine was comparable. Acetylcholine induced endothelium-dependent relaxations, but the sensitivity (pD2: 6.7 +/- 0.3) and maximal relaxation (81% +/- 9%) were slightly less in the gastroepiploic artery than in the mammary artery (pD2: 7.6 +/- 0.2; 100% +/- 0%; p less than 0.05). Histamine induced endothelium-dependent relaxations with a similar sensitivity (pD2: 7.5 +/- 0.3 and 7.2 +/- 0.1), whereas the maximal relaxation was slightly enhanced in the gastroepiploic artery. The relaxation to the nitric oxide donor SIN-1 was identical in the two arteries. Thus the right gastroepiploic artery exhibits better contractility than the internal mammary artery but comparable endothelium-dependent and endothelium-independent relaxations. The good endothelial function of the gastroepiploic artery might be important for graft function and patency, whereas the enhanced contractility may facilitate vasospasm, especially in the presence of high circulating levels of catecholamines.
Yang
Z
Z
Department of Research, University Basel, Switzerland.
Siebenmann
R
R
Studer
M
M
Egloff
L
L
Lüscher
T F
TF
D000109:Acetylcholine / Q000494:pharmacology; D001158:Arteries / Q000502:physiology; D001026:Coronary Artery Bypass; D004730:Endothelium, Vascular / Q000187:drug effects / Q000502:physiology*; D006632:Histamine / Q000494:pharmacology; D006801:Humans; D008323:Mammary Arteries / Q000502:physiology*; D008981:Molsidomine / Q000031:analogs & derivatives / Q000494:pharmacology; D009119:Muscle Contraction / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000502:physiology*; D009638:Norepinephrine / Q000494:pharmacology; D009852:Omentum / Q000098:blood supply*; D011189:Potassium Chloride / Q000494:pharmacology; D013270:Stomach / Q000098:blood supply*; D014665:Vasodilator Agents / Q000494:pharmacology
D014665:Vasodilator Agents; C002385:linsidomine; D011189:Potassium Chloride; D006632:Histamine; D008981:Molsidomine; D000109:Acetylcholine; D009638:Norepinephrine