Year: 2008 | Volumen: 45 # 1
Human Growth Hormone (GH) Receptor and the High Affinity GH-Binding
Authors: Ballerini, María Gabriela, Ropelato, María Gabriela.
Human circulating growth hormone (GH) is partly bound to a high-affinity binding protein (GHBP)
which is derived from proteolytical cleavage of the extracellular domain of the GH receptor. Recently, the
metalloproteinase TACE has been identified as an important enzyme responsive for inducing GHBP shedding.
Although the specific function of GHBP is not fully known, both enhancing and inhibitory roles of this
binding protein on GH action have been proposed. Many reports have demonstrated a close relationship
between GHBP and the liver GH receptor status in physiological conditions and diseases. Moreover, serum
GHBP measurement has been proposed as an useful peripheral index of the GH receptor abundance. Related
to the latter, circulating GHBP concentration would be of special interest for the evaluation of GH
insensitivity due to GH receptor gene abnormalities. In addition, the present review also focus on methodological
problems concerning serum GHBP measurement.
Key words: HGH; GHR; Stat5b; TACE; GHBP