Growth Hormone-Releasing Hormone
The role of hypothalamic growth hormone-releasing hormone (GHRH) in the release of growth hormone (GH) from the pituitary is well established. Extra-hypothalamic growth hormone-releasing hormone (GHRH) plays an important role in infertility. Growth hormone releasing hormone (GHRH) has recently been shown to increase the level of gamma-aminobutyric acid (GABA) and activate GABA receptors (GABARs) in the cerebral cortex. GABA is an inhibitory neurotransmitter that can inhibit seizures. GHRH may play an important role in inhibiting seizures by activating GABAARs. GHRH is produced by tumor cells, acts in an autocrine/paracrine manner, and requires the presence of GHRH receptor (GHRH-R) on the tumor cells to exert its effects. GHRH activity can be effectively blocked by synthetic antagonists of its receptor and hence, the expression of GHRH-R by tumor cells could serve as a predictor of response to GHRH-R antagonist therapy. The neurovascular protective effect of GHRH analogs during the early stage of diabetic retinopathy through their antioxidant and anti-inflammatory properties. GHRH antagonists can be a therapeutic option for thyroid cancer patients.