Background

Calcitonin gene-related peptide plasma levels have frequently been determined as a biomarker for primary headaches. However, published data is often inconsistent resulting from different methods that are not precisely described in most studies.

Methods

We applied a well-proven enzyme-linked immunosorbent assay to measure calcitonin gene-related peptide concentrations in human blood plasma, we modified parameters of plasma preparation and protein purification and used calcitonin gene-related peptide-free plasma for standard solutions, which are described in detail.

Results

Calcitonin gene-related peptide levels are stable in plasma with peptidase inhibitors and after deep-freezing. Calcitonin gene-related peptide standard solutions based on synthetic intercellular fluid or pooled plasma with pre-absorbed calcitonin gene-related peptide influenced the measurements but yielded both comprehensible results. In a sample of 56 healthy subjects the calcitonin gene-related peptide plasma levels varied considerably from low (<50 pg/mL) to very high (>500 pg/mL) values. After a 12-hour exposure of these subjects to normobaric hypoxia the individual calcitonin gene-related peptide levels remained stable.

Conclusion

Buffering with peptidase inhibitors and immediate freezing or processing of plasma samples is essential to achieve reliable measurements. Individuals show considerable differences and partly high calcitonin gene-related peptide plasma levels without detectable pathological reason. Thus plasma measurements are suited particularly to follow calcitonin gene-related peptide levels in longitudinal studies.

The use of data for this study was approved by the Ethics Committee of the Medical

University of Innsbruck (https://www.i-med.ac.at/ethikkommission/; EK Nr: 1242/2017).

中文翻译：

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人血浆中的 CGRP 测量——方法学研究

背景

降钙素基因相关肽血浆水平经常被确定为原发性头痛的生物标志物。然而，由于在大多数研究中没有准确描述的不同方法，公布的数据往往不一致。

方法

我们应用了一种经过充分验证的酶联免疫吸附测定来测量人血浆中降钙素基因相关肽的浓度，我们修改了血浆制备和蛋白质纯化的参数，并使用降钙素基因相关的无肽血浆作为标准溶液。详细。

结果

降钙素基因相关肽水平在使用肽酶抑制剂和深度冷冻后的血浆中是稳定的。基于合成细胞间液或预吸收降钙素基因相关肽的混合血浆的降钙素基因相关肽标准溶液影响测量，但产生了可理解的结果。在 56 名健康受试者的样本中，降钙素基因相关肽血浆水平变化很大，从低 (<50 pg/mL) 到非常高 (>500 pg/mL) 值。在这些受试者暴露于常压缺氧 12 小时后，个体降钙素基因相关肽水平保持稳定。

结论

用肽酶抑制剂缓冲和立即冷冻或处理血浆样品对于实现可靠的测量至关重要。个体表现出相当大的差异和部分高降钙素基因相关肽血浆水平，而没有可检测的病理原因。因此，血浆测量特别适合在纵向研究中跟踪降钙素基因相关肽水平。

本研究使用的数据经医学伦理委员会批准

因斯布鲁克大学（https://www.i-med.ac.at/ethikkommission/；EK Nr：1242/2017）。