膳食黑米皮对载脂蛋白E基因缺陷小鼠诱导型一氧化氮合酶表达的影响

目的:探讨膳食黑米皮对载脂蛋白E基因缺陷小鼠(apoE基因缺陷小鼠)动脉粥样硬化(AS)形成的影响及其作用机制,为AS的膳食防治研究提供理论依据。方法:分离apoE基因缺陷小鼠心脏,用油红O染色法和图像分析法检测小鼠主动脉窦动脉粥样斑块面积的大小。分离小鼠血清,硝酸还原酶法检测一氧化氮(NO^-₂/NO^-₃)含量;分离小鼠主动脉,抽提总蛋白,放射免疫法检测诱导型一氧化氮合酶(iNOS)的活性;抽提总RNA,用逆转录-聚合酶链式反应(RT-PCR)检测iNOSmRNA的表达。结果:黑米皮组apoE基因缺陷小鼠主动脉窦动脉粥样斑块面积显著低于阳性组和白米皮组(P＜0.01)。黑米皮组与白米皮组血清中NO^-₂/NO^-₃含量并无显著差异(P＞0.05);黑米皮组小鼠主动脉iNOS的活性和iNOSmRNA的表达量显著低于阳性组和白米皮组(P＜0.05)。结论:膳食黑米皮可抑制apoE基因缺陷小鼠iNOSmRNA的表达,这可能是黑米皮抗AS作用的机制之一。

Effect of dietary black rice outer layer fraction on inducible nitric oxide synthase expression in apoE-deficient mice

AIM: To explore the effect of dietary black rice outlayer fraction (BRF) on inducible nitric oxide synthase (iNOS) expression, and elucidate the possible mechanism of BRF anti-atherogenesis in apoE-deficient mice. METHODS: After 16 weeks intervention by 5% BRF, aortic iNOS activity in different groups was determined by RIA. iNOS mRNA expression in aorta were analyzed by RT-PCR. RESULTS: Mice in BRF group showed weaker expression of iNOS mRNA and lower iNOS activity than those in positive and WRF group (P<0.05). No significant difference was observed between positive group and WRF group (P>0.05). CONCLUSION: The supplementation of BRF has dramatically reduced aortic sinus atherosclerotic plaque areas compared to WRF in apoE-deficient mice and its action of anti-atherogenesis may be attributed to its inhibition of iNOS activity and iNOS mRNA expression.