Kano T, Mizuchi A, Miyachi Y
Nihon Naibunpi Gakkai Zasshi. 1978 May 20;54(5):654-65. doi: 10.1507/endocrine1927.54.5_654.
A sensitive and specific radioimmunoassay for plasma betamethasone has been developed. The antiserum used was obtained by immunizing rabbits with betamethasone-3-oxime-human serum albumin (BM-3-oxime-HSA) conjugate. The sensitivity was 20 pg and a standard curve was established with a useful range from 20 pg to 4 ng. The cross reactivity of all tested endogenous steroids was less than 0.2%. Cortisol with a cross reactivity of 0.14% caused slight interference at very high concentrations, but this factor is negligible when plasma cortisol level is less than 30 microgram/dl. The calculated interference by cortisol was less than 10%, and plasma not receiving BM consistently gave blanks which were less than 20 pg/tube. Reliability criteria were satisfactory. By this method plasma BM could be measured directly in dichloromethane extract of plasma. The plasma concentrations of BM were measured in normal subjects and patients with liver diseases following oral administration of BM. The peaks of the plasma concentrations for 1.0 mg and 1.5 mg of BM were 345 +/- 40 (n = 3) and 710 +/- 200 ng/dl (n = 5) respectively within 2 hours after administration in normal subjects. After the peak level, plasma BM rapidly fell and disappeared 24 hours after administration in all examined normal subjects. In patients with chronic active hepatitis, the peak levels for 1.0 mg and 1.5 mg of BM were 428 +/- 48 (n = 4) and 837 +/- 83 ng/dl (n = 7) respectively within 2 hours after administration. However, the peak levels of plasma BM were higher than those of normal subjects, and the disappearance of BM from the blood was markedly delayed, reaching a level of 318 +/- 88 nad 622 +/- 148 ng/dl respectively for 1.0 mg and 1.5 mg of BM at 5 hours. The relatively high plasma concentration of BM, ranging from 135 to 170 ng/dl was maintained even 24 hours after administration in all patients with chronic active hepatitis. The disappearance of cortisol from the blood also rapidly fell in normal subjects, but was markedly delayed in patients with chronic active hepatitis. There was good correlation between the severity of the liver disease as measured by the ICG retention at fifteen minutes and removals of BM and cortisol from the blood.
已开发出一种灵敏且特异的血浆倍他米松放射免疫测定法。所用抗血清是通过用倍他米松 -3-肟 -人血清白蛋白（BM -3-肟 -HSA）偶联物免疫兔子获得的。灵敏度为20皮克，建立的标准曲线有效范围为20皮克至4纳克。所有测试的内源性甾体的交叉反应率均小于0.2%。交叉反应率为0.14%的皮质醇在非常高的浓度下会引起轻微干扰，但当血浆皮质醇水平低于30微克/分升时，该因素可忽略不计。计算得出的皮质醇干扰小于10%，未接受BM的血浆始终给出小于20皮克/管的空白值。可靠性标准令人满意。通过这种方法可直接在血浆的二氯甲烷提取物中测量血浆BM。在正常受试者和肝病患者口服BM后测量其血浆BM浓度。在正常受试者中，给药后2小时内，1.0毫克和1.5毫克BM的血浆浓度峰值分别为345±40（n = 3）和710±200纳克/分升（n = 5）。在所有检查的正常受试者中，达到峰值水平后，血浆BM迅速下降并在给药后24小时消失。在慢性活动性肝炎患者中，给药后2小时内，1.0毫克和1.5毫克BM的峰值水平分别为428±48（n = 4）和837±83纳克/分升（n = 7）。然而，血浆BM的峰值水平高于正常受试者，并且BM从血液中的消失明显延迟，在5小时时，1.0毫克和1.5毫克BM分别达到318±88和622±148纳克/分升的水平。在所有慢性活动性肝炎患者中，即使在给药后24小时，BM的血浆浓度仍维持在相对较高的水平，范围为135至170纳克/分升。皮质醇从血液中的消失在正常受试者中也迅速下降，但在慢性活动性肝炎患者中明显延迟。通过15分钟时吲哚氰绿滞留量衡量的肝病严重程度与BM和皮质醇从血液中的清除之间存在良好的相关性。
