Growth hormone (GH) is secreted by the
hypothalamus – pituitary – gonadal (HPG) axis and the
GH/IGF axis in all vertebrates. GH is released into
the bloodstream and participates in diverse differentiation
processes in various target tissues, including functional
stimulation of growth and development
( MART Í NEZ-MORENO et al. 2011). It was proposed that GH
plays a role in the reproductive function of males and
females during growth and differentiation. It was also suggested
that GH participates in steroidogenesis and gametogenesis
( HULL and HARVEY 2000; KOMISAREK et al. 2011).
BACHELOT et al. (2002) reported that GH defi ciency
decreases ovulation and the number of follicles in the
mouse. In the GH receptor gene and GH-binding protein
gene knockout mouse model, the amount of healthy
follicles was signifi cant lower in comparison with normal
mice. GH mRNA has been found in the germinal cells in
spermatogonia, spermatocytes, spermatids and Leydig
cells ( MART Í NEZ-MORENO et al. 2011). In vitro studies
showed that GH can signifi cantly enhance the stimulation
by other hormones on the target tissues ( SANDERS
and HARVEY 2004; TSILCHOROZIDOU and CONWAY 2004).
Recent studies suggested that prior to and after the onset
of egg laying, GH plays a physiological role in the growth,