20K-GH and its use in detecting GH abuse

Ghrelin Stimulation of Growth Hormone Isoforms: Parallel Secretion of Total and 20-kDa Growth Hormone and Relation to Insulin Sensitivity in Healthy Humans

“…This further supports the notion that the current isoform approach to detect doping with GH is not affected by GH secretory peaks. Furthermore, our data demonstrating that the ratio of 20-kDa over total GH is stable during conditions of enhanced GH release also support the proposal that detecting changes in the 20-kDa to total GH ratio could be used as an alternative to doping tests (46).…”

Detection of Doping with Recombinant Human Growth Hormone

“…Similar conclusions can also be drawn from other studies [22], that 20-kDa hGH is co-secreted and circulates at a constant ratio with 22-kDa hGH under various physiological and pharmacological conditions and that administration of exogenous hGH markedly and transiently alters the ratio of 20to 22-kDa hGH, suggesting that the determination of the ratio may serve as a useful marker for exogenous 22-kDa hGH administration. In a recent paper [49], the normal male (n = 392), 20-kDa hGH/22-kDa hGH was in the range of 11.91 ± 4.84 g/g, and normal female (n = 50) was 13.99 ± 4.55 g/g. These results confirmed that both 22-kDa hGH and 20-kDa hGH tend to be higher in women than in men, but no significant difference in 22-kDa hGH/20-kDa hGH was observed between them.…”

“…A very recent paper [49] reported one of the on-going projects of hGH isoform assay for detecting hGH abuse. Primary anti-hGH isoform antibody was immobilized on polystyrene microbeads, giving the unique fluorescence so-called Spectral Address and 22-kDa hGH and 20-kDa hGH assays were performed in a medium suspended with a mixture of antibodycoated microbeads.…”

Annual banned‐substance review: analytical approaches in human sports drug testing

“…A comparable detection window was accomplished by Irie et al, measuring specifically 22 kDa and 20 kDa hGH only. [53] Investigating three groups of athletes (long/middledistance runners, football players, and cyclists), 22 kDa/20kDa ratios between 10.97 (±4.80) and 14.24 (±4.46) were found, which were described as not significantly different from the control group. In contrast, administration studies with hGH yielded 'markedly increased' ratios of 22 kDa/20kDa concentrations, which unfortunately were not further described.…”