Singh S, Verma M, Nain C K, Co L, Goel R C, Sharma B K
Department of Internal Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
Int J Clin Pharmacol Ther. 1998 Oct;36(10):545-8.
The aim of this study was to distinguish paraoxonase phenotypes by dual substrate method.
166 unrelated healthy northwestern Indian Punjabis were studied for basal paraoxonase activity (P), in presence of 1 M NaCl (salt-activated) using paraoxon as substrate and arylesterase activity (A) using phenylacetate as substrate.
The mean (+ SD) activity of these in population was 70.43 (+/-30.41), 103.11 (+/-42.87) nmol/min/ml plasma and 36.81 (+/- 9.87) micromol/min/ml plasma, respectively, with no significant difference in sexes. Based on the ratio of SAP activity to A activity, 3 distinct phenotypes could be determined with gene frequencies of PONA and PONB being 0.845 and 0.155, respectively. Between P and A, and SAP and A in both A and AB phenotypes, significant correlation was observed (A = r 0.34 and 0.62, p < 0.01; B = r 0.31 and 0.81, p > 0.01), suggesting that both enzymes belong to the same group.
Though northwestern Indian Punjabis have trimodal paraoxonase activity, the majority is either low homozygous (AA) or heterozygous (AB) type with enzyme activity lower than Europids.
本研究旨在通过双底物法区分对氧磷酶表型。
对166名无亲缘关系的印度西北部旁遮普健康人群进行研究，以对氧磷为底物测定基础对氧磷酶活性（P），在1M氯化钠存在下（盐激活）以苯乙酸为底物测定芳基酯酶活性（A）。
这些人群中P、A和盐激活对氧磷酶（SAP）活性的平均值（±标准差）分别为70.43（±30.41）、103.11（±42.87）nmol/分钟/毫升血浆和36.81（±9.87）微摩尔/分钟/毫升血浆，性别间无显著差异。根据SAP活性与A活性的比值，可确定3种不同表型，PONA和PONB的基因频率分别为0.845和0.155。在A和AB表型中，P与A以及SAP与A之间均观察到显著相关性（A表型中r分别为0.34和0.62，p<0.01；B表型中r分别为0.31和0.81，p>0.01），表明这两种酶属于同一组。
尽管印度西北部旁遮普人群具有三峰型对氧磷酶活性，但大多数为低纯合子（AA）或杂合子（AB）类型，酶活性低于欧洲人。
