Davidson L, Vandongen R, Beilin L J, Arkwright P D
J Clin Endocrinol Metab. 1984 Mar;58(3):415-8. doi: 10.1210/jcem-58-3-415.
The study examined the plasma concentration of free and sulfate-conjugated norepinephrine (NE) and epinephrine (E) at rest and after vigorous bicycle exercise. Free and total catecholamines were measured by a modified radioenzymatic assay using external standards. This assay was less costly and, in subjects with normal renal function, plasma levels were highly comparable to those obtained using internal standards. Exercise was associated with a predictable rise in plasma free NE and E concentration, which correlated with the hemodynamic changes, and a significant decrease in the levels of catecholamine sulfate conjugates. There was an inverse relationship between the degree of conjugation and the free levels of NE and E both at rest and after exercise. This suggests that the degree of conjugation is another factor determining the concentration of free amines in plasma.
该研究检测了静息状态以及剧烈自行车运动后血浆中游离型和硫酸结合型去甲肾上腺素（NE）及肾上腺素（E）的浓度。游离型和总儿茶酚胺通过使用外标物的改良放射酶分析法进行测定。该分析成本较低，在肾功能正常的受试者中，血浆水平与使用内标物获得的水平高度可比。运动与血浆游离NE和E浓度的可预测升高相关，这与血流动力学变化相关，且儿茶酚胺硫酸结合物水平显著降低。在静息状态和运动后，结合程度与NE和E的游离水平之间均呈负相关。这表明结合程度是决定血浆中游离胺浓度的另一个因素。
