基于酚酞指示法半定量健康人群唾液中尿素酶活性

目的 建立一种半定量唾液中尿素酶活性的酚酞指示法。方法 基于尿素酶可以特异性地催化尿素水解并引起溶液pH变化, 可直观评价健康人群唾液中尿素酶活性, 通过优化尿素溶液浓度、反应时间等因素并评估其对检测限的影响。结果 当尿素溶液浓度为7 g/L, 反应时间5 min时尿素酶活性的检测限为 0.80 U/mL, 反应时间17 h时尿素酶活性的检测限为0.04 U/mL。进一步通过200份不同唾液样本实际测试, 确定健康人群唾液中尿素酶活性应不高于0.064 U/mL。结论 该方法操作简便、成本低, 可直观半定量唾液中尿素酶活性, 为口腔和全身疾病的早期评估和诊断提供依据, 也可为胃中易产生尿素酶的幽门螺旋杆菌的检测提供一定的技术参考。

Semi-quantitative determination of urease activity in saliva of healthy human by phenolphthalein indicator method

Objective To establish a semi-quantitative method for the detection of the urease activity in saliva was by a phenolphthalein indicator. Methods According to the principle that the pH varies as urease specifically catalyzing hydrolysis of urea in a solution and causing pH change, the urease activity in the saliva of healthy people could be visually evaluated. The urea solution concentration, reaction time and other factors were optimized and its impact on the detection limit was evaluated. Results While a urea solution with the concentration of 7 g/L was adopted, the limit of detection (LOD) of urease activity were 0.80 U/mL and 0.04 U/mL, corresponding to the reaction time of 5 min and 17 h, respectively. A further study based on 200 saliva samples from healthy human showed that the urease activity in saliva should be less than 0.064 U/mL. Conclusion This method is easy to operate with low cost, and suitable for visual semi-quantitative determination of urease activity in saliva, therefore providing a basis for early assessment and diagnosis of oral and systemic diseases and a technical reference for detection of Helicobacter Pylori caused by stomach illness.