The Impact of Triptorelin on Hormone Levels in Human and Its Metabolite Confirmation Using Liquid Chromatography-Ion Trap/Time-of-Flight Mass Spectrometry (LC/MS-IT-TOF) and Liquid Chromatography-Orbitrap (LC-Orbitrap) for Doping Control Analysis.

Triptorelin, a synthetic gonadotrophin-releasing hormone (GnRH), is mainly used in the clinical treatment of prostate cancer. The mechanism initially stimulates luteinizing hormone (LH) and testosterone secretion followed by suppression, resulting in a reduction in cancer progression. However, GnRHs are prohibited in doping control because of the indirect surge of LH and testosterone. Therefore, GnRH analog detection and confirmation are enforced by World Anti-Doping Agency (WADA) requirements. The effects of triptorelin on LH and endogenous steroid levels in urine and serum of five prostate cancer patients taking triptorelin for the first time were investigated and compared with leuprorelin. The samples were collected at 0.0 h, 3.0 h, 6.0 h, 1 month, and 3 months later after drug administration. The effect of triptorelin on LH levels was measured using a sandwich enzyme-linked immunoassay (ELISA). Testosterone and endogenous steroid levels were monitored using gas chromatography coupled with mass spectrometry (GC/MS). Triptorelin showed an advantage over leuprorelin on LH and testosterone suppression, which is preferable to use for prostate cancer treatment. In this study, triptorelin (5-10), a unique in vivo metabolite, was found in urine and serum and verified with synthetic triptorelin (5-10). The metabolite was analyzed using liquid chromatography combined with Orbitrap (LC-Orbitrap) and liquid chromatography coupled with ion trap/time-of-flight mass spectrometry (LC/MS-IT-TOF). When triptorelin levels are undetectable, the presence of triptorelin (5-10) in human urine can be used as evidence that triptorelin is being misused in doping control.