Lawson D L, Mehta J L, Saldeen K, Mehta P, Saldeen T G
Department of Medicine, University of Florida, College of Medicine, Gainesville 32610.
Eicosanoids. 1991;4(4):217-23.
Dietary supplementation with fish oil results in augmentation of endothelium-dependent vasorelaxation in experimental animals. The present study was designed to evaluate the direct in vitro effects of omega-3 polyunsaturated fatty acids (omega-3 PUFAs) on vascular reactivity in isolated rat aortic rings. Aortic rings were incubated with the omega-6PUFA arachidonic acid (AA, 10(-7) M) or the omega-3 PUFAs eicosapentaenoic acid (EPA, 10(-7) M) and docosahexaenoic acid (DHA, 10(-7) M) in an organ bath at 37 degrees C. Following contraction with norepinephrine, changes in isometric force were measured in response to the endothelium-dependent vasodilators acetylcholine (ACh, 10(-10) to 10(-5) M) or the calcium ionophore A23187 (10(-10) to 10(-5) M). Parallel sets of vascular rings were pretreated with the cyclooxygenase inhibitor indomethacin (10(-5) M) or the inhibitor of nitric oxide synthesis NG-monomethyl L-arginine (L-NMMA 5 x 10(-5) M) prior to treatment with AA or EPA. Treatment of rings with EPA resulted in an increase (P less than 0.05) in ACh-mediated vasorelaxation compared both to AA-treated and buffer-treated rings (maximum relaxation 83 +/- 5% vs 46 +/- 5% and 63 +/- 4%, respectively). A similar augmentation was observed in DHA-treated rings. Pretreatment of rings with indomethacin or I-NMMA decreased (P less than 0.05) the ACh-mediated vasorelaxation, although EPA-treated rings showed less (P less than 0.05) attenuation of ACh response compared to AA-treated or untreated control rings.(ABSTRACT TRUNCATED AT 250 WORDS)
在实验动物中，膳食补充鱼油可增强内皮依赖性血管舒张。本研究旨在评估ω-3多不饱和脂肪酸（ω-3 PUFAs）对离体大鼠主动脉环血管反应性的直接体外作用。将主动脉环在37℃的器官浴中与ω-6多不饱和脂肪酸花生四烯酸（AA，10⁻⁷ M）或ω-3多不饱和脂肪酸二十碳五烯酸（EPA，10⁻⁷ M）和二十二碳六烯酸（DHA，10⁻⁷ M）一起孵育。用去甲肾上腺素收缩后，测量等长力的变化，以响应内皮依赖性血管舒张剂乙酰胆碱（ACh，10⁻¹⁰至10⁻⁵ M）或钙离子载体A23187（10⁻¹⁰至10⁻⁵ M）。在用AA或EPA处理之前，平行组的血管环先用环氧化酶抑制剂吲哚美辛（10⁻⁵ M）或一氧化氮合成抑制剂NG-单甲基L-精氨酸（L-NMMA 5×10⁻⁵ M）预处理。与AA处理组和缓冲液处理组的环相比，用EPA处理环导致ACh介导的血管舒张增加（P<0.05）（最大舒张分别为83±5%、46±5%和63±4%）。在DHA处理的环中也观察到类似的增强。用吲哚美辛或I-NMMA预处理环可降低（P<0.05）ACh介导的血管舒张，尽管与AA处理组或未处理的对照组环相比，EPA处理组的环对ACh反应的减弱较少（P<0.05）。（摘要截短于250字）
