Background The development of analytical approaches to help reduce the risk of growth hormone (GH) doping is important to fair competition and the health of athletes. However, the reliable detection of GH use remains challenging. The identification of novel biomarkers of GH administration could lead to a better understanding of the physiological response to GH, more sensitive detection of the illicit use of GH in sport, and better management of patients treated for GH disorders. Methods We developed a targeted liquid chromatography–tandem mass spectrometry method to simultaneously quantify the carboxyl-terminal propeptide of type III procollagen (P-III-CP) and type III collagen degradation products in human serum. Following proteolysis, we instituted a simple acid precipitation step to reduce digested sample complexity before peptide immunoenrichment, which improved the recovery of one target peptide from serum. We evaluated the concentration of each biomarker at different age ranges and after GH administration in healthy participants. Results The assay was linear over an estimated concentration range of 0.3 to1.0 nM and 0.1 to 0.4 nM for each surrogate peptide of P-III-CP and collagen fragments, respectively. Intra-day and inter-day coefficients of variation were ≤15%. Biomarker concentrations appeared to vary with age and to reflect age-specific collagen turnover. Moreover, their concentrations changed after GH administration. Conclusions Our method quantifies the proteins belonging to the family of P-III-CP and type III collagen degradation products in human serum, which could be used to detect GH administration in athletes and better understand diseases involving GH therapy or altered type III collagen turnover.

中文翻译：

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一种靶向液相色谱-串联质谱法同时定量 III 型前胶原的羧基末端区域的肽，胶原周转的生物标志物

背景 开发有助于降低生长激素 (GH) 兴奋剂风险的分析方法对公平竞争和运动员的健康非常重要。然而，GH 使用的可靠检测仍然具有挑战性。识别 GH 给药的新生物标志物可以更好地了解对 GH 的生理反应，更灵敏地检测 GH 在运动中的非法使用，以及更好地管理接受 GH 疾病治疗的患者。方法 我们开发了一种靶向液相色谱-串联质谱法，同时定量人血清中 III 型前胶原 (P-III-CP) 和 III 型胶原降解产物的羧基末端前肽。蛋白水解后，我们建立了一个简单的酸沉淀步骤，以在肽免疫富集之前降低消化样品的复杂性，从而提高了从血清中回收一种目标肽的能力。我们评估了健康参与者在不同年龄范围和 GH 给药后每种生物标志物的浓度。结果 对于 P-III-CP 的每种替代肽和胶原片段，该测定分别在 0.3 至 1.0 nM 和 0.1 至 0.4 nM 的估计浓度范围内呈线性。日内和日间变异系数≤15%。生物标志物浓度似乎随年龄而变化，并反映了特定年龄的胶原蛋白更新。此外，它们的浓度在 GH 给药后发生了变化。结论 我们的方法量化了人血清中属于 P-III-CP 家族的蛋白质和 III 型胶原降解产物，