Cunningham  and Ganong  stated that growth hormone perform its effects on target tissues through liberation of somatomedin
C also called [IGF.sub.1] and [IGF.sub.2].
Growth hormone also works indirectly by stimulating liver cells to produce and secrete polypeptide molecules known as somatomedins
, the best studied of which is insulin-like growth factor-1 (IGF-1).
Also earlier experimental evidence acquired with the use of animals is in agreement with a possible role of somatomedins
in stimulation of heart hypertrophy (Huang et al., 2003).
Dual control of cell growth by somatomedins
and platelet-derived growth factor.
GH causes the liver to form a group of small proteins, called somatomedins
, that stimulate growth in all tissues.