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人體乳內動脈、橈動脈與大隱靜脈內皮細胞一氧化氮和超極化因子的差異及其臨床意義

Objective To study the differences in nitric oxide (NO) release and endotheliumderived hyperpolarizing factor (EDHF)mediated hyperpolarization among human internal mammary artery (IMA), radial artery (RA), and sephenous vein (SV) by direct measurement of the signal of NO and membrane potential. Methods The present study was divided into four groups: IMA (n=15), RA (n=6), SV (n=23), and surgically prepared SV group(dilatation with normal saline solution at a pressure of 100600 mm Hg, PV, n=9). All vascular segments taken from 29 patients undergoing coronary artery bypass grafting between October 2009 and September 2010 in the Fu 〖CM(159mm]Wai Hospital Beijing. The vascular segments were placed in an organ chamber, and the NOsensitive electrode and intracellular glass microelectrode were used to directly measure the NO release and membrane potential changes in response to acetylcholine (ACh) and bradykinin (BK) before and after incubation with NGnitroLarginine, indomethacin, and oxyhemoglobin. Results (1)The basal release of NO in IMA group was 16.8±1.6 nmol/L, n=13, significantly greater thanthat in SV group (9.9±2.8 nmol/L, n=13, Plt;0.05) and RA group (11.9±1.8 nmol/L, n=6, Plt;0.05). Compared with SV group, NO basal release in RA group was greater (Plt;0.05). (2)The AChinduced NO release was greater in IMA group than in RA group or SV group, while BKinduced NO release was greater in SV group than in RA group. (3) Both basal(3.4±1.4 nmol/L, n=9, Plt;0.05) and ACh, and BKinduced NO release in PV group were significantly reduced.(4) EDHFmediated hyperpolarization was greater in IMA group than in SV group orRA group ［ACh -5 log M: -9.4±1.5 mV(n=10) vs. -4.5±1.1 mV(n=17), -9.7±1.9 mV(n=6), Plt;0.05；BK -7 log M: -10.9±1.5 mV(n=8) vs. -5.1±0.5 mV(n=8), RA -5.8±0.9 mV(n=6), Plt;0.05). Compare with SV group AChinduced EDHFmediated hyperpolarization in RA group was greater(ACh -5 log M:-9.7±1.9 mV, n=6, vs. -4.5±1.1 mV, n=17, Plt;0.01). Conclusions (1) IMA is superior to RA and SV in terms of NO basal and stimulated release and EDHFmediated hyperpolarization. (2) Compared with SV, both NO basal release and EDHFmediated hyperpolarization in RA were significantly greater. (3) After surgical preparation and pressure dilatation, both basal and stimulated release of NO in SV were severely impaired.