Detection Of Doping With RhGH

Human Growth hormone (hGH) is one of the most important hormones, which promotes the human body growth and protein assimilation. Recent years, recombinant human growth hormone (rhGH) is abused in sports to improve athletic ability, meanwhile, the detection of recombinant human growth hormone abuse is a huge challenge in antidoping research. There are two main detection methods:the direct method and indirect method. Direct method is the isoform approach, at the basis of differentiation of GH isoforms in human body. While indirect method is a bio-markers approach, which monitors certain blood parameters effected by the administration of hGH. Isoform approach is the only method authorized by World Anti-Doping Agency (WADA). Both of the two methods have advantages and disadvantages, based on method of detection technology and potential applications are required to further research and discussion.For healthy male Chinese population,25healthy male volunteers were randomly divided into3groups. Treatment was administered by subcutaneous injection for14days,0.1IU/kg body weight/day. Blood samples were taken fasting at baseline (1hour before the first injection) and at2,4,8,12,23,34hours after injection, as well as4,6,8,10,12,14,15,16,1718,21,28,35days.Direct method results showed that after a single injection, RecGH/PitGH peaked at2-4hours, the adverse percent at hour12was63.2%, no positive sample at hour23. For continuous injection, the adverse percent at hour10was77.2%, at hour21was5.3%. The detection window was only10-16hours. In addition, the result indicated that the high individual viaration in PitGH is due to unstable antigen-antibody reaction of different isofoms of PitGH. According to the analytical data and the WADA technical document, we suggest that the decision limit of kit1for male should be decreased, as well as perfect the antibody of the detetion assay.On the indirect method, IGF-1viarated significantly after the rejection of rhGH, it increased at day2, reached the peak at day10, retuned to the baseline at day21.The viaration of IGFBP3is unsignificantly cross correlated to the administration, and also the daily viaration is very high, so it is not appropriate to be used as a marker for detection of doping with rhGH. P-â…¢-P increased from day6, reached the peak at dayl6, retuned to the baseline at day35. The discriminant formula was constructed wih IGF-â…  and P-â…¢-P. According to the formula, the detection window can delay to72hours. However the formulas from different research cannot be iter-used.Combined the direct and indirect method, we suggest that the antibody of the direct detection assay and decision limit should be improved; the discriminant formula or decision limit should be adjusted in different ethnicity or laboratories. At last, according the different characteristic of two detection method, we suggest that using two methods for different purposes, the direct methond for taching the cheat, while the indirect method more for targeting the athlete and deterent.