Nishikaze O, Kobayashi T
Clin Chem. 1977 Dec;23(12):2332-4.
Sodium sulfate increases the hydrolysis of urinary 17-hydroxycorticosteroid glucuronides with beta-glucuronidase preparations derived from Helix pomatia because it removes the inhibitory activity of urinary high-molecular-weight substances. For maximum hydrolysis of urinary 17-hydroxycorticosteroid glucuronides, the hydrolysis [5 ml of urine, 0.5 ml of 2 mol/liter acetate buffer (pH 5.0)] should be conducted in the presence of sodium sulfate (final concentration: 80 g/liter) with (a) 600 Fishman units of the enzyme per milliliter of urine (18 h at 52 degrees C) or (b) with 1500 units of the enzyme per milliliter of urine (3 h at 57 degrees C). Under conditions a, analytical recovery of steroid glucuronides added to 12 urine samples was 99 +/- 2.1% (96-102%). Values obtained for 20 urine samples with this method were 99 +/- 2.7% (93-104%) as great as those yielded by a method in which 600 units of the enzyme from bovine liver are used together with sodium sulfate (18 h at 48 degrees C).
硫酸钠可增强源自苹果螺的β-葡萄糖醛酸酶制剂对尿中17-羟皮质类固醇葡萄糖醛酸苷的水解作用，因为它能消除尿中高分子量物质的抑制活性。为使尿中17-羟皮质类固醇葡萄糖醛酸苷达到最大程度的水解，水解反应[5毫升尿液，0.5毫升2摩尔/升乙酸盐缓冲液（pH 5.0）]应在硫酸钠存在下（终浓度：80克/升）进行，其中（a）每毫升尿液加入600费什曼单位的酶（52℃下18小时），或（b）每毫升尿液加入1500单位的酶（57℃下3小时）。在条件a下，添加到12份尿液样本中的类固醇葡萄糖醛酸苷的分析回收率为99±2.1%（96 - 102%）。用该方法对20份尿液样本测得的值是使用来自牛肝的600单位酶与硫酸钠一起（48℃下18小时）的方法所得到值的99±2.7%（93 - 104%）。
