RADIOIMMUNOLOGICAL DETERMINATION OF HUMAN C-PEPTIDE IN SERUM
RADIOIMMUNOLOGICAL DETERMINATION OF HUMAN C-PEPTIDE IN SERUM
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DOI：
10.1007/bf01222104
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发表时间：
1975-01-01
期刊：
影响因子：
8.2
通讯作者：
HEDING, LG
中科院分区：
文献类型：
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作者：
HEDING, LG
本文描述了血清中c肽的常规放射免疫测定方法。用人b成分免疫豚鼠，产生抗人c肽抗体。12只动物中有9只在6个月内产生了有用的抗体。用与Sepharose偶联的胰岛素抗体结合血清中的人胰岛素原和胰岛素，离心后在上清中测定c肽。该方法的检出限为0.003 mol c -肽（100 μl）。误差的主要来源有：(1)正常血清和糖尿病血清缺乏c肽，其125i - tyrr - c肽位移在0 ~ 0.16 nM之间（6种不同的抗血清）。只有一种抗血清（m1181）没有位移，在正常和糖尿病血清中检测到的c肽值低于另一种抗血清，在无c肽的血清中检测到的c肽值为0.07 nM。提示大多数抗血清中发现的位移是由于血清中与c肽或胰岛素原无关的物质引起的。(2)胰腺提取物和血清的连续稀释可能产生与合成标准品略有不同的稀释曲线。讨论了可能的解释。这些错误的来源可以通过正确选择抗血清来消除或减少。15例正常人、8例成熟型糖尿病患者和10例胰岛素需用糖尿病患者空腹血清中c肽的浓度分别为（m1181） 0.35±0.09、0.74±0.51和0.21±0.14 （nM, mean±SD）。1.75 g/kg口服葡萄糖1 h后，分别为2.24±0.71、2.34±1.18和0.42±0.24 nM。
A routine radioimmunoassay for human C-peptide in serum is described. Antibodies against human C-peptide were raised by immunizing guinea pigs with human b-component. Nine out of 12 animals produced useful antibodies within 6 months. Insulin antibodies coupled to Sepharose were used to bind human proinsu-lin and insulin in the serum and after centrifugation C-peptide was determined in the supernatant. The detection limit of the assay (calculated as 2 SD from zero) was about 0.003 pmole of C-peptide (in 100 μl). The main sources of error were: (1) Normal and diabetic sera devoid of C-peptide gave a displacement of125I-Tyr-C-peptide varying from 0 to 0.16 nM (6 different antisera). Only one antiserum (M 1181) showed no displacement, and the values of C-peptide determined with this antiserum in normal and diabetic sera were lower than the values determined with another antiserum, which gave a value of 0.07 nM in the sera free of C-peptide. It is suggestedthat displacement found with most antisera is due to substances in serum that are not related to C-peptide or proinsulin. (2) Serial dilutions of pancreatic extracts and sera may yield dilution curves slightly different to those of the synthetic standard. Possible explanations are discussed. These sources of error can be eliminated or reduced by the proper selection of antisera. Fasting sera from 15 normals, 8 maturity-onset diabetics and 10 insulin-requiring diabetics showed the following concentrations of C-peptide: (M 1181) 0.35 ± 0.09, 0.74 ± 0.51 and 0.21 ± 0.14 (nM, mean ± SD). One hour after 1.75 g/kg oral glucose the values increased to 2.24 ± 0.71, 2.34 ± 1.18 and 0.42 ± 0.24 nM.