[Reactivity of internal mammary artery and saphenous vein used in human myocardial revascularization: studies with endogenous vasoconstrictors and vasodilators].
Biopsies of human internal mammary artery and saphenous vein were examined to ascertain the functional integrity of these vessels employed in myocardial revascularization. Studies were performed in vascular rings derived from 28 patients without previous consideration of age, sex, underlying additional pathology or drug treatments previous to and during surgery. Isometric muscle contraction of the circular muscle layer was monitored. Endothelin-1 (ET) is equipotent as a vasoconstrictor in arteries and veins, with a potency at least 10 to 100-fold that of noradrenaline (NA) or serotonin (5-HT). The potency of ET, NA or 5-HT is unaltered by mechanical removal of the endothelial cell layer. Arterial rings precontracted with NA relaxed in a concentration-dependent fashion in the presence of acetylcholine and sodium nitroprusside. Whereas the potency of nitroprusside was unaltered by removal of the endothelium, the efficacy of acetylcholine was greatly reduced. Saphenous vein rings were refractory to acetylcholine but not nitroprusside. Results open new perspectives to explain the larger patency of internal mammary artery grafts as compared to that of saphenous vein grafts in human myocardial revascularization.
Huidobro-Toro
J P
JP
Departamento de Fisiología, Facultad de Ciencias Biológicas, Facultad de Medicina, Universidad Católica de Chile.
Irarrázaval
M J
MJ
Donoso
M V
MV
Peschke
H
H
Salas
C
C
López
L F
LF
Larraín
E
E
Morán
S
S
Fournier
A
A
Becker
P
P
D004730:Endothelium, Vascular / Q000187:drug effects / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008323:Mammary Arteries / Q000187:drug effects* / Q000502:physiology; D009204:Myocardial Revascularization; D012501:Saphenous Vein / Q000187:drug effects* / Q000502:physiology; D014661:Vasoconstriction; D014662:Vasoconstrictor Agents / Q000494:pharmacology*; D014664:Vasodilation; D014665:Vasodilator Agents / Q000494:pharmacology*
D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents
Reactividad de la arteria mamaria interna y vena safena utilizadas en revascularización miocárdica humana: estudios con vasoconstrictores y vasodilatadores endógenos.