Background

The growth hormone releasing hormone receptor (GHRH-R) is found predominantly on the somatotroph of the anterior pituitary[1,2]. In its classic physiologic pathway, GHRH produced by neurons in the arcuate nucleus of the hypothalamus is released from the median eminence and delivered to the pituitary by the pituitary portal circulation[3]. Here GHRH acts at the GHRH-R of somatotrophs to trigger both the synthesis and release of growth hormone (GH)[4]. The actions of GHRH are opposed by somatostatin and potentiated by ghrelin (a GH secretagogue), each acting at its own somatotroph receptor[5]. The integrated response to these signals is a complex pulsatile pattern of GH release to the peripheral circulation. During development GHRH is required for normal somatotroph proliferation and maturation[6]. Afte