Biomaterial Database

Hypoxia increases vasodilator release from internal mammary artery and saphenous vein grafts. 1998

P J Pearson, and P R Evora, and B Discigil, and H V Schaff

Division of Cardiovascular Surgery, Mayo Clinic, Rochester, Minnesota 55905, USA.

BACKGROUND Greater release of endothelium-derived nitric oxide is implicated in the superior patency of the internal mammary artery (IMA) used in coronary artery bypass grafting. This study compared the release of endothelium-derived nitric oxide into the lumen of the IMA and the saphenous vein under normoxic versus hypoxic conditions. METHODS Segments of canine IMA and saphenous vein were perfused in vitro. Vasorelaxant activity was measured as vasodilatation of coronary artery smooth muscle induced by the effluent. RESULTS Effluents from the IMA and saphenous vein caused comparable vasodilation of coronary artery smooth muscle. The vasodilatation reversed when perfusion was switched to a prosthetic conduit. Vasodilator activity from the IMA and saphenous vein was attenuated by removing the intima of the grafts or by adding N(G)-monomethyl-L-arginine (10(-4) mol/L) or N(G)-nitro-L-arginine (10(-4) mol/L), two inhibitors of nitric oxide synthesis. Indomethacin attenuated vasorelaxant activity from saphenous vein grafts but not IMA grafts (n = 10). Vasodilator release from the IMA and saphenous vein was augmented by hypoxia. This augmentation was inhibited by indomethacin (n = 10, p < 0.05). Hypoxic augmentation reversed with return to normoxia. CONCLUSIONS The release of endothelium-derived nitric oxide and prostacyclin from bypass grafts into the lumen, particularly during hypoxemia, could promote the vasodilation of distal coronary arterial beds, enhancing myocardial perfusion.

UI	MeSH Term	Description	Entries
D007213	Indomethacin	A non-steroidal anti-inflammatory agent (NSAID) that inhibits CYCLOOXYGENASE, which is necessary for the formation of PROSTAGLANDINS and other AUTACOIDS. It also inhibits the motility of POLYMORPHONUCLEAR LEUKOCYTES.	Amuno,Indocid,Indocin,Indomet 140,Indometacin,Indomethacin Hydrochloride,Metindol,Osmosin
D008323	Mammary Arteries	Arteries originating from the subclavian or axillary arteries and distributing to the anterior thoracic wall, mediastinal structures, diaphragm, pectoral muscles and mammary gland.	Internal Mammary Artery,Internal Thoracic Artery,Arteries, Internal Mammary,Arteries, Internal Thoracic,Arteries, Mammary,Artery, Internal Mammary,Artery, Internal Thoracic,Artery, Mammary,Internal Mammary Arteries,Internal Thoracic Arteries,Mammary Arteries, Internal,Mammary Artery,Mammary Artery, Internal,Thoracic Arteries, Internal,Thoracic Artery, Internal
D009131	Muscle, Smooth, Vascular	The nonstriated involuntary muscle tissue of blood vessels.	Vascular Smooth Muscle,Muscle, Vascular Smooth,Muscles, Vascular Smooth,Smooth Muscle, Vascular,Smooth Muscles, Vascular,Vascular Smooth Muscles
D009569	Nitric Oxide	A free radical gas produced endogenously by a variety of mammalian cells, synthesized from ARGININE by NITRIC OXIDE SYNTHASE. Nitric oxide is one of the ENDOTHELIUM-DEPENDENT RELAXING FACTORS released by the vascular endothelium and mediates VASODILATION. It also inhibits platelet aggregation, induces disaggregation of aggregated platelets, and inhibits platelet adhesion to the vascular endothelium. Nitric oxide activates cytosolic GUANYLATE CYCLASE and thus elevates intracellular levels of CYCLIC GMP.	Endogenous Nitrate Vasodilator,Mononitrogen Monoxide,Nitric Oxide, Endothelium-Derived,Nitrogen Monoxide,Endothelium-Derived Nitric Oxide,Monoxide, Mononitrogen,Monoxide, Nitrogen,Nitrate Vasodilator, Endogenous,Nitric Oxide, Endothelium Derived,Oxide, Nitric,Vasodilator, Endogenous Nitrate
D010975	Platelet Aggregation Inhibitors	Drugs or agents which antagonize or impair any mechanism leading to blood platelet aggregation, whether during the phases of activation and shape change or following the dense-granule release reaction and stimulation of the prostaglandin-thromboxane system.	Antiaggregants, Platelet,Antiplatelet Agent,Antiplatelet Agents,Antiplatelet Drug,Blood Platelet Aggregation Inhibitor,Blood Platelet Antagonist,Blood Platelet Antiaggregant,PAR-1 Antagonists,Platelet Aggregation Inhibitor,Platelet Antagonist,Platelet Antagonists,Platelet Antiaggregant,Platelet Antiaggregants,Platelet Inhibitor,Protease-Activated Receptor-1 Antagonists,Antiplatelet Drugs,Blood Platelet Aggregation Inhibitors,Blood Platelet Antagonists,Blood Platelet Antiaggregants,Platelet Inhibitors,Agent, Antiplatelet,Aggregation Inhibitor, Platelet,Antagonist, Blood Platelet,Antagonist, Platelet,Antiaggregant, Blood Platelet,Antiaggregant, Platelet,Drug, Antiplatelet,Inhibitor, Platelet,Inhibitor, Platelet Aggregation,PAR 1 Antagonists,Platelet Antagonist, Blood,Platelet Antiaggregant, Blood,Protease Activated Receptor 1 Antagonists
D011464	Epoprostenol	A prostaglandin that is a powerful vasodilator and inhibits platelet aggregation. It is biosynthesized enzymatically from PROSTAGLANDIN ENDOPEROXIDES in human vascular tissue. The sodium salt has been also used to treat primary pulmonary hypertension (HYPERTENSION, PULMONARY).	Prostacyclin,Prostaglandin I2,Epoprostanol,Epoprostenol Sodium,Epoprostenol Sodium Salt, (5Z,9alpha,11alpha,13E,15S)-Isomer,Flolan,Prostaglandin I(2),Veletri
D003326	Coronary Circulation	The circulation of blood through the CORONARY VESSELS of the HEART.	Circulation, Coronary
D004285	Dogs	The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)	Canis familiaris,Dog
D004730	Endothelium, Vascular	Single pavement layer of cells which line the luminal surface of the entire vascular system and regulate the transport of macromolecules and blood components.	Capillary Endothelium,Vascular Endothelium,Capillary Endotheliums,Endothelium, Capillary,Endotheliums, Capillary,Endotheliums, Vascular,Vascular Endotheliums
D004791	Enzyme Inhibitors	Compounds or agents that combine with an enzyme in such a manner as to prevent the normal substrate-enzyme combination and the catalytic reaction.	Enzyme Inhibitor,Inhibitor, Enzyme,Inhibitors, Enzyme