HGH or human growth hormone is a protein hormone of 190 amino
acids, which is synthesized and secreted by the Somatotroph
cells (hence called Somatotropin) in the anterior pituitary. The
genes for human growth hormone are localized in the q22-24
region of chromosome 17. The structure of HGH includes four
helices necessary for functional interaction with the GH
receptor. Structurally, HGH is homologous to prolactin and
chorionic somatomammotropin and it appears as if the three share
some evolutionarily connection. The triad is known to promote
growth and aid the lactogenic activity.
Human Growth Hormone Secretion
Synthesis and secretion of HGH is controlled by many factors
such as exercise, nutrition, sleep, stress and sometimes even by
growth hormone itself. The control, however, are wielded by two
hypo-thalamic hormones (Growth hormone-releasing hormone or GHRH
and Somatostatin or SS) and one hormone present in the stomach
(Ghrelin).
Functions of HGH
Human growth hormone contributes in the building up of the human
body. HGH has two different types of effects on the human
tissues and the human system as a whole - direct and indirect.
The direct effects are the upshot of the growth hormone binding
its receptor to the target cells. Indirect effects are
stimulated by an insulin-like growth factor-I (IGF-I), a hormone
secreted by the liver and other tissues in response to growth
hormone action. In fact, most of the growth promoting effects of
HGH are the consequence of IGF-I acting on the target cells.
Thus, it is apparent that HGH or Somatotropin plays a vital role
in major physiological processes, including growth and
metabolism.
HGH & Growth
The major role of growth hormone in effecting body growth is to
stimulate the liver and various other tissues to secrete IGF-I.
IGF-I. This, in-turn, it provokes proliferation of Chondrocytes
(cartilage cells), resulting in bone growth.
HGH & Metabolism
Human growth hormone has been found to have important effects on
protein, lipid and carbohydrate metabolism. These effects in
some are direct, others indirect and a few showing mixed
effects.
Although height growth is an all-too-manifest effect of HGH on
the human system, it has several other specific and essentially
functions. These functions range from protein synthesis to
building muscle mass, calcium retention to mineralization of
bones, stimulating the immune system to maintaining fuel
homeostasis, etc.
This is all about real human growth hormone. Biosynthetic human
growth hormone, also known as recombinant human growth hormone
and abbreviated as rHGH was first used for remedial use in the
U.S. in 1985. Since then, the biosynthetic variety of HGH has
nearly sidelined the pituitary-prompted human growth hormone,
especially in therapeutic use.
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