Sundaram R S, Van Loon J A, Tucker R, Weinshilboum R M
Department of Pharmacology, Mayo Clinic, Rochester, MN 55905.
Clin Pharmacol Ther. 1989 Nov;46(5):501-9. doi: 10.1038/clpt.1989.178.
Phenol sulfotransferase (PST) catalyzes the sulfate conjugation of phenolic drugs. All human tissues studied contain a thermostable (TS) form of PST, which catalyzes the sulfate conjugation of "simple" phenols such as p-nitrophenol, and a thermolabile (TL) form, which catalyzes the sulfation of dopamine and other monoamines. In the present study we tested the hypothesis that genetically controlled levels of TS and TL PST activity in the platelet, as well as inherited variations in the thermal stability of platelet TS PST, might reflect those same characteristics of the enzyme in the less accessible tissue, human small intestinal mucosa. Platelet TS and TL PST activities and TS PST thermal stability were measured in blood samples from 45 randomly selected healthy subjects, and 14 of those subjects were selected to have intestinal biopsies performed. There was a significant correlation between levels of platelet and jejunal mucosal TS PST activity (rs = 0.574, p less than 0.030), but there was not a significant correlation between levels of TL PST activity in the two tissues (rs = 0.265, p = 0.368). There was also a significant correlation between the trait of TS PST thermal stability in the two tissues (rs = 0.828, p less than 0.0001). These observations suggest that inherited variations in TS PST activity and thermal stability in an easily obtained tissue, the platelet, might be used to predict individual differences of those properties of the enzyme in the human small intestine, an organ that plays an important role in drug metabolism.
酚磺基转移酶(PST)催化酚类药物的硫酸结合反应。所有研究过的人体组织都含有一种热稳定(TS)形式的PST,它催化对硝基苯酚等“简单”酚类的硫酸结合反应,以及一种热不稳定(TL)形式,它催化多巴胺和其他单胺的硫酸化反应。在本研究中,我们检验了这样一个假设,即血小板中TS和TL PST活性的基因控制水平,以及血小板TS PST热稳定性的遗传变异,可能反映了在难以获取的组织——人类小肠黏膜中该酶的相同特征。对45名随机选择的健康受试者的血样进行了血小板TS和TL PST活性以及TS PST热稳定性的测定,并选取其中14名受试者进行了肠道活检。血小板和空肠黏膜TS PST活性水平之间存在显著相关性(rs = 0.574,p < 0.030),但两种组织中TL PST活性水平之间没有显著相关性(rs = 0.265,p = 0.368)。两种组织中TS PST热稳定性特征之间也存在显著相关性(rs = 0.828,p < 0.0001)。这些观察结果表明,在易于获取的组织——血小板中,TS PST活性和热稳定性的遗传变异,可能可用于预测该酶在人类小肠中的这些特性的个体差异,小肠是在药物代谢中起重要作用的器官。