토끼 복부 대동맥에서 활성 산소종에 의해 야기되는 혈관 내피 세포 의존성 혈관 이완에 미치는 영향에 대한 Esmolol과 Metoprolol의 항산화 효과

Abstract

Background : The ischemia, the oxygen depleted state, and following reperfusion may result in serious tissue damage. The reactive oxygen species (ROS) is a free radical that has strong oxidizing power and is a major cause for tissue damage in ischemia and reperfusion injury. The ß-blocker is clinically commonly used drug and its ROS scavenging effect besides its beta adrenergic blocking effect came to the fore. This study was performed for verifying the ROS scavenging effect of ß-blockers such as esmolol and metoprolol and for verifying the mechanisms on it. Methods : The rabbit abdominal aorta segments were exposed to ROS generated by electrolysis(EL) of bathing solution (K-H solution). EL was performed with a constant direct current of 15 mA for 35 s. Before EL, we added various concentrations of esmolol or metoprolol up to 3 x 10-4 M to the bathing solution. The contraction was induced with NE (10-6 M) and relaxation was induced with cumulative Ach (3 × 10-8, 10-7, 3 × 10-7, and 10-6 M).The changes of the aortic tension were recorded. 3-Amino-1, 2, 4-Triazole (3AT) or diethyldithiocarbamate trihydrate (DETCA) was added and the influence of 3AT or DETCA on endothelium protective effect of esmolol or metoprolol was also investigated. Results : Esmolol groups and metoprolol groups showed relaxation by cumulative Ach in a dose dependent manner(P<0.05). 3AT 50 mM made no alteration to the relaxation in the esmolol or metoprolol pretreated group. But, DETCA 0.5 mM disturbed the relaxation in the esmolol(3 x 10-4 M) pretreated group (P<0.05) and metoprolol (3 x 10-4 M) pretreated group (P<0.05). Conclusion : Esmolol and metoprolol have antioxidant effect in a dose dependent manner. Superoxide anion radical scavenging effect plays a part in antioxidant effect of esmolol and metoprolol.