Takami H, Shikata J, Horie H, Horiuchi J, Sakurai H, Ito K
1st Dept. Surg., Teikyo Univ. Sch. Med.
Gan To Kagaku Ryoho. 1989 Jun;16(6):2219-25.
For the purpose of determining the significance of CGRP for endocrine tumors, we attempted to establish CGRP radioimmunoassay (RIA) system and to measure plasma CGRP levels in patients with endocrine tumor. One ml of plasma (EDTA-2K + aprotinin 500.KIE/ml) was applied to Sep-Pak C 18 column, and was eluted by 90% MeOH plus 0.1% TFA. The eluted samples were used for RIA. RIA was performed by two day-one day system (delayed assay). B/F separation was made by two Ab-PEG method. Cross-reactivity of antisera was 0.0025% and below 0.0001% against PTH and calcitonin in human, respectively. The standard curve of CGRP showed a dose response curve. Results of dilution and reproduction tests were excellent. Normal range of serum CGRP was 6.7 +/- 3.0 pg/ml (M +/- SD) and the cut-off level was determined to be 12.7 pg/ml. Plasma CGRP showed 128,323 and 2,010 pg/ml in three preoperative patients with medullary thyroid carcinoma, indicating extremely high levels. On the other hand, plasma CGRP levels increased in 2/7, 2/4, 2/5, and 0/3 in patients with parathyroid adenoma, benign insulinoma, carcinoid and pheochromocytoma, respectively. Correlation between CGRP level and calcitonin levels was significant (r = 0.789) in only 16 patients with medullary thyroid carcinoma. This study suggests that our CGRP RIA system was satisfactory for clinical use and measurement of CGRP may be potentially useful for clearing the pathophysiology of neuroendocrine tumors, although CGRP level was raised in patients with medullary thyroid carcinoma.
为了确定降钙素基因相关肽（CGRP）在内分泌肿瘤中的意义，我们试图建立CGRP放射免疫分析（RIA）系统，并测定内分泌肿瘤患者血浆中的CGRP水平。将1ml血浆（含乙二胺四乙酸二钾（EDTA - 2K）+抑肽酶500KIU/ml）应用于Sep - Pak C18柱，并用90%甲醇加0.1%三氟乙酸洗脱。洗脱后的样品用于RIA。RIA采用两日 - 一日系统（延迟测定）。通过双抗体 - 聚乙二醇（PEG）法进行B/F分离。抗血清与人甲状旁腺激素（PTH）和降钙素的交叉反应率分别为0.0025%和低于0.0001%。CGRP的标准曲线呈剂量反应曲线。稀释和重复性试验结果良好。血清CGRP的正常范围为6.7±3.0pg/ml（均值±标准差），临界值确定为12.7pg/ml。三名术前甲状腺髓样癌患者的血浆CGRP分别为128、323和2010pg/ml，表明水平极高。另一方面，甲状旁腺腺瘤、良性胰岛素瘤、类癌和嗜铬细胞瘤患者血浆CGRP水平升高的比例分别为2/7、2/4、2/5和0/3。仅在16例甲状腺髓样癌患者中，CGRP水平与降钙素水平之间存在显著相关性（r = 0.
