Zygowicz E R, Sunderman F W, Horak E, Dooley J F
Clin Chem. 1977 Dec;23(12):2311-23.
Concanavalin A inhibits serum 5'-nucleotidase activity, without causing significant inhibition of alkaline phosphatase activity. This observation serves as the basis for a new method for assaying the 5'-nucleotidase activity in serum, which depends upon the difference between the enzymic hydrolysis of adenosine-5'-monophosphate in the presence and absence of concanavalin A. A denosine released by the 5'-nucleotidase reaction is deaminated by a coupled reaction with adenosine deaminase to liberate inosine and ammonia, and ammonia is measured colorimetrically by the Berthelot reaction. In sera from 40 healthy adult persons, 5'-nucleotidase activity averaged 6.4 U/liter (SD, +/-2.0; range, 3-12). In sera from 100 patients, measurements of 5'-nucleotidase activity by the new assay averaged 8% lower than by a generally accepted method in which phenyl phosphate is used to suppress hydrolysis of adenosine-5'-monophosphate by alkaline phosphatase activity. The clinical validy of the new assay was tested by measuring serum 5'-nucleotidase activities in rats with bile duct ligation and in rats treated with thioacetamide to induce hepatocellular injury.
伴刀豆球蛋白A可抑制血清5'-核苷酸酶活性，而对碱性磷酸酶活性无明显抑制作用。这一观察结果为一种测定血清中5'-核苷酸酶活性的新方法奠定了基础，该方法基于在有和没有伴刀豆球蛋白A存在的情况下，腺苷-5'-单磷酸酶促水解的差异。5'-核苷酸酶反应释放的腺苷通过与腺苷脱氨酶的偶联反应脱氨，生成肌苷和氨，氨通过伯特洛反应进行比色测定。在40名健康成年人的血清中，5'-核苷酸酶活性平均为6.4 U/升（标准差，±2.0；范围，3 - 12）。在100名患者的血清中，通过新方法测定的5'-核苷酸酶活性平均比使用磷酸苯酯抑制碱性磷酸酶活性对腺苷-5'-单磷酸水解的普遍接受方法低8%。通过测量胆管结扎大鼠和用硫代乙酰胺处理以诱导肝细胞损伤的大鼠的血清5'-核苷酸酶活性，对新测定方法的临床有效性进行了测试。
