Abstract:
Kisspeptin-10 is a peptide hormone capable of increasing circulating follicle-stimulating hormone, luteinizing hormone and testosterone levels in humans. Clinically, these effects suggest its use as a treatment for infertility. However, its testosterone-increasing effect indicates potential misuse in sports. As such, it is included in the 2024 World Anti-Doping Agency Prohibited List. This work describes the successful validation of an initial testing procedure (screening) and a confirmation procedure for kisspeptin-10 in urine using liquid chromatography-mass spectrometry. Additionally, kisspeptin-10 was incubated in human serum to mimic endogenous metabolism to improve method sensitivity, as previous research had demonstrated a rapid elimination time of only 30 min after injection (in rats). Four metabolites, corresponding to peptide fragments y9, y8, y7 and y5, were found and added to the ITP in full scan mode. A degradation product discovered during early experimentation was found to probably be caused by oxidation of the tryptophan residue into a kynurenine residue. Further research should elucidate the kinetic parameters of the reaction to improve product stability. Using the validated confirmation procedure, a black-market vial of kisspeptin-10 was analysed. The product contained no unexpected impurities, although it appeared to have undergone more degradation than the purchased reference standard.
摘要:
Kisspeptin-10是一种能够增加循环卵泡刺激素的肽激素,人类黄体生成素和睾丸激素水平。临床上,这些效果表明它可以作为不孕症的治疗方法。然而,它的睾酮增加效应表明运动中潜在的误用。因此,它被列入2024年世界反兴奋剂机构禁止名单。这项工作描述了使用液相色谱-质谱对尿液中kisspeptin-10的初始测试程序(筛选)和确认程序的成功验证。此外,kisspeptin-10在人血清中孵育以模拟内源性代谢,以提高方法灵敏度,因为以前的研究已经证明了一个快速消除时间仅30分钟后注射(在大鼠)。四种代谢物,发现对应于肽片段y9、y8、y7和y5并以全扫描模式添加到ITP中。发现在早期实验中发现的降解产物可能是由色氨酸残基氧化成犬尿氨酸残基引起的。进一步的研究应阐明反应的动力学参数,以提高产物的稳定性。使用经过验证的确认程序,分析了一小瓶黑市的kisspeptin-10。产品不含意外杂质,尽管它似乎比购买的参考标准经历了更多的降解。