DIFFICULTIES WITH HUMAN GROWTH HORMONE TESTING

Bidlingmaier, M., Wu, Z., & Strasburger, C. J. (2003). Problems with GH doping in sports. Journal of Endocrinology Investigations, 26(9), 924-931.

Human (hGH) use is considered as doping. However, until today the likelihood of being punished for using recombinant hGH is very limited: once injected, it is believed to be undetectable by laboratories. No official test is implemented in the doping control procedures, and the only situation when athletes were found guilty of doping with hGH arose from actions of customs officers or policemen arresting athletes carrying ampoules with them. The primary reason for the lack of an accepted test is the amino acid sequence identity between the main fraction of pituitary derived hGH and recombinant hGH. It is difficult to discriminate between endogenous and exogenous hGH. In addition, hGH is known to have a very short half-life time in circulation of around 15 minutes.

Recent efforts of endocrine researchers led to the identification of two main strategies promising to be useful for the detection of recombinant hGH application. Changes in GH-dependent parameters after administration of recombinant GH have been shown to be possible indicators of GH abuse, because the increase in various parameters following recombinant hGH administration exceeds the variability commonly observed in normal, healthy subjects. A more direct approach focuses on changes in the hGH isoform pattern in serum occurring after injection of recombinant hGH. Because of the negative feedback on pituitary hGH secretion, the relative abundance of isoforms other than 22 kD are greatly reduced after administration of recombinant hGH, which only consists of the 22 kD hGH isoform.

Implication. Testing for recombinant hGH remains a daunting task and is still in preliminary development.

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