Department of Cardiac Surgery, University of Naples Federico II, and Department of Cardiology, Azienda Ospedaliera Santobono-Pausillipon, Naples, Italy.
Ann Thorac Surg. 2012 Dec;94(6):1934-9. doi: 10.1016/j.athoracsur.2012.06.040. Epub 2012 Aug 9.
After coronary artery bypass graft surgery, older women have less favorable clinical outcome and lower conduit patency compared with men. This less favorable outcome can be in part ascribed to impaired endothelium-derived nitric oxide (eNOS) production. This study evaluated endothelial nitric oxide synthase expression in internal mammary artery from postmenopausal women undergoing coronary artery bypass graft surgery.
Internal mammary artery segments were obtained from 20 postmenopausal woman and 20 matched male patients. Twenty more segments from younger patients were used as controls. Expression of eNOS messenger RNA in internal mammary artery endothelial cells were evaluated by polymerase chain reaction and real-time quantitative reverse transcription polymerase chain reaction. The eNOS protein level was assayed by Western blot. Vascular dynamics of specimens were evaluated by organ chamber methodology.
In postmenopausal women, the band of messenger RNA for eNOS was reduced by 37.4% and by 25.2%, respectively, compared with matched men and the control group (62.6%±4.8% versus 74.8%±5.3%, p<0.001). In comparison with the control group lane, the eNOS protein immunoreactive band was 44.2% decreased in postmenopausal women and 34.5% decreased in matched men, and was significantly decreased in postmenopausal women as compared with matched men (55.8%±4.6% versus 65.5%±5.2%, p<0.001). Nitric oxide-mediated vasomotor dynamics were consistent with reduced eNOS production.
Internal mammary artery endothelial cells from women after menopause undergoing coronary surgery have impaired expression of messenger RNA for eNOS and reduced eNOS levels. Reduced bioactivity of nitric oxide translates into impaired endothelial metabolism that could contribute to worse surgical outcome.
与男性相比，女性在冠状动脉旁路移植手术后的临床结局较差，血管通畅率较低。这种较差的结果在一定程度上可归因于内皮衍生的一氧化氮（eNOS）产生受损。本研究评估了行冠状动脉旁路移植术的绝经后女性的内乳动脉中的内皮型一氧化氮合酶（eNOS）表达。
从 20 名绝经后女性和 20 名匹配的男性患者中获取内乳动脉段。另外 20 个年轻患者的血管段用作对照。通过聚合酶链反应和实时定量逆转录聚合酶链反应评估内乳动脉内皮细胞中 eNOS 信使 RNA 的表达。通过 Western blot 测定 eNOS 蛋白水平。通过器官室方法评估标本的血管动力学。
与匹配的男性和对照组相比，绝经后女性的 eNOS 信使 RNA 带分别降低了 37.4%和 25.2%（62.6%±4.8%比 74.8%±5.3%，p<0.001）。与对照组相比，绝经后女性的 eNOS 蛋白免疫反应性条带降低了 44.2%，匹配的男性降低了 34.5%，绝经后女性与匹配的男性相比明显降低（55.8%±4.6%比 65.5%±5.2%，p<0.001）。一氧化氮介导的血管舒缩动力学与 eNOS 产生减少一致。
接受冠状动脉手术的绝经后女性的内乳动脉内皮细胞中 eNOS 的信使 RNA 表达受损，eNOS 水平降低。一氧化氮的生物活性降低转化为内皮代谢受损，这可能导致手术结果更差。
