Ten healthy subjects used to performing regular physical activity and eight subjects affected by idiopathic isolated GH deficiency (GHD) were enrolled; 22- and 20-kDa GH secretion and its biological activity were evaluated in response to pharmacological stimuli such as arginine, L-dopa or glucagon in GHD children, while the hormonal response to exercise was studied according to Bruce protocol in healthy subjects. We found a significant increase in 22- and 20-kDa GH level in healthy subjects after monitored physical exercise (MPE; basal 0.28±0.12 vs 7.37±2.08 ng/ml and basal 0.076±0.04 vs 0.18±0.05 ng/ml, respectively). Furthermore, the 22-kDa/20-kDa ratio significantly increased in children who had undergone MPE and the GH bioactivity basal mean value also increased significantly after exercise (basal 2.86±0.76 vs 7.64±1.9 ng/ml). The mean value of 22-kDa GH in GHD patients increased significantly following GH pharmacological stimulation (2.78±0.63 ng/ml) when compared with mean basal (0.20±0.11 ng/ml) value. In the GHD group the basal concentration of 20-kDa GH significantly increased following GH pharmacological stimulation (0.34±0.11 vs 0.72±0.2 ng/ml); the 22-kDa/20-kDa ratio significantly increased too. Likewise, GH bioactivity in children with GHD increased significantly after pharmacological stimulation test (basal 2.53±0.56 vs 7.33±1.26 ng/ml). Both GH isoform concentrations and their biological activity are significantly increased in healthy subjects after submaximal exercise protocol and in GHD children after pharmacological stimuli.
|Number of pages||5|
|Journal||Journal of Endocrinological Investigation|
|Publication status||Published - Jun 2008|
- GH isoforms
- Growth hormone
ASJC Scopus subject areas