Yeates R A, Laufen H, Leitold M
Mol Pharmacol. 1985 Dec;28(6):555-9.
The rate of loss of the sulfhydryl group, determined with the Ellman reagent, was used to derive second order rate constants for the reaction of a series of organic nitrates with a series of sulfhydryl compounds. For the organic nitrates, increases in the rate of reaction with cysteine, in general, ran parallel both with increases in pharmacological potency (flow in the Langendorff heart) and with increases in total clearance. Cysteine was the most active sulfhydryl compound examined, which is compatible with a possible role as an important nitrate receptor. Under some conditions the rate of loss of the sulfhydryl group was much greater than the rate of formation of nitrite ion. This indicates the presence of a reaction intermediate, probably a thionitrate. It is suggested that, in vivo, a thionitrate could function as an important intermediate in the activation of guanylate cyclase.
用埃尔曼试剂测定的巯基损失速率，用于推导一系列有机硝酸盐与一系列巯基化合物反应的二级速率常数。对于有机硝酸盐，一般来说，与半胱氨酸反应速率的增加，既与药理活性（Langendorff心脏中的血流）的增加平行，也与总清除率的增加平行。半胱氨酸是所检测的最具活性的巯基化合物，这与它可能作为重要硝酸盐受体的作用相符。在某些条件下，巯基的损失速率远大于亚硝酸根离子的形成速率。这表明存在反应中间体，可能是硫代硝酸盐。有人提出，在体内，硫代硝酸盐可能作为鸟苷酸环化酶激活的重要中间体发挥作用。
