Methods The serum level of Lp ( a) was measured by latex-enhanced nephelometry immunoassay with HITACHI 7170A automatic analyzer. The level of NO was determined by nitric acid reductase chromoptometry assay. 方法利用日立7170A全自动生化分析仪采用胶乳增强比浊法测定血清Lp(a),采用硝酸还原酶比色法测定NO。