Lambert A, Frost J, Ratcliffe W A, Robertson W R
Clin Endocrinol (Oxf). 1985 Sep;23(3):253-61. doi: 10.1111/j.1365-2265.1985.tb00221.x.
The disappearance in vitro of ACTH from whole human blood and plasma held at 22 degrees C has been monitored using a dispersed adrenal cell bioassay and an unextracted radioimmunoassay. In three normal subjects after a metyrapone test and two patients with Addison's disease, endogenous bioactive ACTH levels were unchanged for at least 1 h in blood and 2 h in plasma. Moreover greater than 50% of the bioactive plasma ACTH was still present in the plasma samples from the patients with Addison's disease after 24 h incubation at ambient temperatures. Human pituitary ACTH (1-39), spiked into plasma from dexamethasone suppressed subjects to give a concentration of 250 ng/l, was stable by bioassay for at least 2 h. No loss of biological activity was observed on subjecting plasma from a patient with Addison's disease or spiked plasma to two cycles of thawing at 37 degrees C and freezing at -70 degrees C or thawing at 20 degrees C and freezing at -20 degrees C. Some loss of bioactivity (20%) occurred on subjecting the patient's, but not ACTH-spiked plasma to four cycles of thawing at 20 degrees C/freezing at -20 degrees C. We conclude that bioactive ACTH (endogenous or exogenous) may be more stable in vitro in human blood and plasma than has been previously thought. If our studies can be confirmed in a larger series then it may be that conditions for handling blood specimens for ACTH assays could be reappraised.
使用分散肾上腺细胞生物测定法和未提取放射免疫测定法监测了在22℃下保存的全血和血浆中促肾上腺皮质激素（ACTH）的体外消失情况。在3名接受甲吡酮试验后的正常受试者和2名艾迪生病患者中，内源性生物活性ACTH水平在血液中至少1小时保持不变，在血浆中2小时保持不变。此外，在环境温度下孵育24小时后，艾迪生病患者血浆样本中仍有超过50%的生物活性血浆ACTH存在。将人垂体ACTH（1-39）添加到地塞米松抑制受试者的血浆中，使其浓度达到250 ng/l，通过生物测定法至少2小时保持稳定。对艾迪生病患者的血浆或添加ACTH的血浆进行两个循环的37℃解冻和-70℃冷冻或20℃解冻和-20℃冷冻后，未观察到生物活性丧失。对患者的血浆（而非添加ACTH的血浆）进行四个循环的20℃解冻/-20℃冷冻后，出现了一些生物活性丧失（20%）。我们得出结论，生物活性ACTH（内源性或外源性）在人血和血浆中的体外稳定性可能比之前认为的更高。如果我们的研究能在更大规模的系列研究中得到证实，那么可能需要重新评估处理用于ACTH测定的血液标本的条件。
