Growth hormone production and role in the reproductive system of female chicken

• GH and its receptors are expressed in the chicken ovary and oviduct.
• Role of GH includes regulation of steroidogenesis, proliferation and apoptosis.
• In reproductive system GH can act as endocrine and/or paracrine/autocrine regulator.

The expression and role of growth hormone (GH) in the reproductive system of mammals is rather well established. In birds the limited information thus far available suggests that GH is an endocrine or paracrine/autocrine regulator of ovarian and oviductal functions too. GH and its receptors are expressed in all compartments of the ovary and oviduct and change accordingly to physiological state. The intra-ovarian role of GH likely includes the regulation of steroidogenesis, cell proliferation and apoptosis, the modulation of LH action and the synthesis of IGFs (insulin-like growth factors). In the oviduct, GH is also involved in the regulation of oviduct-specific protein expression. The present study provides a review of current knowledge on the presence and action of GH in the female reproduction, in which it is likely that act in endocrine, autocrine or paracrine mechanisms.