The effect of a period of intensive exercise on the isoform test to detect growth hormone doping in sports

Effect of fermented oyster extract on growth promotion in Sprague-Dawley rats

Background

Oysters (Crassostrea gigas) are a popular marine product worldwide and have the advantage of nutritional benefits. This study aimed to investigate the effect of fermented oyster extract (FO) on growth promotion, including analysis of body size, bone microarchitecture, hematology and biochemistry in vivo.

Methods

The amount of nutrients and gamma aminobutyric acid (GABA) were determined. Sprague–Dawley rats were randomly divided into four groups: the control group, FO 50 group (FO 50 mg/kg), and FO 100 group (FO 100 mg/kg) were administered orally once daily and the recombinant human growth hormone (rhGH) group (200 μg/kg) was intraperitoneally injected once daily for 14 days.

Results

Oral administration of FO 100 significantly increased body length and had no effect on organ damage or hematological profiles. However, administration of rhGH significantly induced hypertrophy of the liver, kidney and spleen along with a marked increase in body length. Tibia length and the growth plate were increased, and bone morphometric parameters were slightly improved by FO and rhGH administration. Serum analysis showed that the levels of GH and insulin like growth factor-1 (IGF-1) were slightly upregulated by FO administration. Nevertheless, the protein expression of hepatic IGF-1 was markedly increased by FO 100 and rhGH administration.

Conclusions

FO have high content of GABA, and induced positive effects on body length, tibial length, growth-plate length and hepatic IGF-1 synthesis in SD rats with no toxicity or alterations of hematological profile. Therefore, these results suggest that GABA-enriched FO could be considered a potential alternative treatment for growth stimulation.

Alteration in cardiac PI3K/Akt/mTOR and ERK signaling pathways with the use of growth hormone and swimming, and the roles of miR21 and miR133

Athletes misuse recombinant human growth hormone (r-hGH) to enhance their performance. Although r-hGH is known to increase cardiac hypertrophy, the underlying molecular mechanism remains unclear. The aim of the present study was to investigate the role of r-hGH in cardiac intracellular signaling pathways and of miR-21 and miR-133 expression in rat hearts during exercise. A total of 36 adult male Sprague-Dawley rats were divided into sedentary control (SC, n=9), swimming exercise (SE, n=8), r-hGH (GH, n=10) and swimming exercise plus r-hGH (SE-GH, n=9) groups. The exercise groups completed a 1-h swimming exercise 5 times a week for 8 weeks. Subcutaneous r-hGH was administered as 0.3 mg/kg/day. Phosphoinositide-3-kinase (PI3K), serine/threonine protein kinase 1 (AKT1), extracellular signal-regulated kinase (ERK), microRNA (miR)-21 and miR-133 expression was evaluated in ventricular muscle by real-time quantitative polymerase chain reaction. Protein expression of PI3K, AKT1, ERK and mechanistic target of rapamycin (mTOR) was also assessed by immunohistochemistry. Statistical differences were analyzed by two-way ANOVA. PI3K and AKT1 expression and the gene and protein levels was notably increased in the SE-GH group compared with in SC ventricular tissues (P<0.05). mTOR protein expression was higher in the GH, SE and SE-GH groups compared with in the SC group (P<0.05, <0.05 and <0.001, respectively). ERK gene/protein expression was similar across all groups. miR-21 and miR-133 levels in ventricular muscle were higher in the SE and GH groups than those in the SC group. In summary, growth hormone application coupled with swimming exercise appeared to affect the PI3K/AKT/mTOR signaling pathway in the left ventricular tissue of rats; however, ERK signaling pathway appeared inactive in physiological left ventricular hypertrophy caused by swimming and GH administration over 8 weeks. Furthermore, GH treatment resulted in increased miR-21 and miR-133 expression. Future study by our group will aim to assess the effects of higher dose GH treatment.

Analytical progresses of the World Anti-Doping Agency Olympic laboratories: a 2016 update from London to Rio

The 2016 Olympic and Paralympic Games, the biggest event in human sports, was held in Rio de Janeiro with more than 10,500 athletes from 206 countries over the world competing for the highest of sports honors, an Olympic medal. With the hope that the Olympic ideal accompanies all aspects of the XXXI Olympiad, WADA accredited antidoping laboratories use the spearhead of analytical technology as a powerful tool in the fight against doping. This review summarizes the main analytical developments applied in antidoping testing methodology combined with the main amendments on the WADA regulations regarding analytical testing starting from the 2012 London Olympics until the 2016 Olympic Games in Rio de Janeiro.

hGH isoform differential immunoassays applied to blood samples from athletes: decision limits for anti-doping testing

OBJECTIVE

To detect hGH doping in sport, the World Anti-Doping Agency (WADA)-accredited laboratories use the ratio of the concentrations of recombinant hGH ('rec') versus other 'natural' pituitary-derived isoforms of hGH ('pit'), measured with two different kits developed specifically to detect the administration of exogenous hGH. The current joint compliance decision limits (DLs) for ratios derived from these kits, designed so that they would both be exceeded in fewer than 1 in 10,000 samples from non-doping athletes, are based on data accrued in anti-doping labs up to March 2010, and later confirmed with data up to February-March 2011. In April 2013, WADA asked the authors to analyze the now much larger set of ratios collected in routine hGH testing of athletes, and to document in the peer-reviewed literature a statistical procedure for establishing DLs, so that it be re-applied as more data become available.

DESIGN

We examined the variation in the rec/pit ratios obtained for 21,943 screened blood (serum) samples submitted to the WADA accredited laboratories over the period 2009-2013. To fit the relevant sex- and kit-specific centiles of the logs of the ratios, we classified 'rec/pit' ratios based on low 'rec' and 'pit' values as 'negative' and fitted statistical distributions to the remaining log-ratios. The flexible data-driven quantile regression approach allowed us to deal with the fact that the location, scale and shape of the distribution of the modeled 'rec/pit' ratios varied with the concentrations of the 'rec' and 'pit' values. The between-kit correlation of the ratios was included in the fitting of the DLs, and bootstrap samples were used to quantify the estimation error in these limits. We examined the performance of these limits by applying them to the data obtained from investigator-initiated hGH administration studies, and in athletes in a simulated cycling stage race.

RESULTS

The mean and spread of the distribution of the modeled log-ratios depended in different ways on the magnitude of the rec and pit concentrations. Ultimately, however, the estimated limits were almost invariant to the concentrations, and similar to those obtained by fitting simpler (marginal) log-normal and Box-Cox transformed distributions. The estimated limits were similar to the (currently-used) limits fitted to the smaller datasets analyzed previously. In investigator-initiated instances, the limits distinguished recent use of rec-hGH from non-use.

CONCLUSIONS

The distributions of the rec/pit ratios varied as a function of the rec and pit concentrations, but the patterns in their medians and spreads largely canceled each other. Thus, ultimately, the kit- and sex-specific ratio DL obtained from the simpler model was very close to the 'curve of DLs' obtained from the more complex one. Both were close to previously established limits.

Heat acclimation decreases the growth hormone response to acute constant-load exercise in the heat

OBJECTIVE

The major objective of this study was to elucidate the effect of heat acclimation on blood growth hormone (GH) response to moderate intensity exhausting exercise in the heat. In addition, the potential relationship between inter-individual differences in GH response to exercise and variability in exercise-induced sweat loss was investigated.

DESIGN

Twenty young men completed three exercise tests on a treadmill: H1 (walk at 60% VO₂peak until exhaustion at 42 °C), N (walk at 22 °C; duration equal to H1) and H2 (walk until exhaustion at 42 °C after a 10-day heat acclimation program). Core temperature (T(c)) was recorded continuously and venous blood samples were taken before, during and after each exercise test. Exercise-induced sweat production was calculated on the basis of body mass change taking into account water intake and the volume of blood samples drawn.

RESULTS

Lower pre-exercise T(c), lower rate of rise in T(c) during exercise, and prolonged time to exhaustion in H2 compared with H1 revealed that the subjects successfully achieved an acclimated state. Overall, serum GH level was higher in H1 compared with both N and H2 (p<0.001) but did not differ between the two latter trials (p>0.05). T(c) correlated with serum GH concentration (r=0.615, p<0.01). Analysis of the individual data revealed a group (n=9) possessing a threshold-like pattern of the relationship between T(c) and blood GH response, whereas a plateau-like pattern was evident in the rest of the subjects (n=11). Both sweat production (r=0.596; p<0.001) and the rate of sweat production (r=0.457; p<0.001) correlated with the growth hormone area under the curve.

CONCLUSION

Heat acclimation decreases the GH response to moderate intensity exhausting exercise in the heat. GH may have a modest stimulating effect on whole-body sweat production during exercise.