Luteinizing hormone releasing hormone (LHRH, also termed gonadotropin releasing hormone GNRH), is a decapeptide involved in the control of human reproduction. There are two genes, LHRH I and II which encode two hormones (Seeburg & Adelman 1984, White et al. 1998). They are produced by hypothalamic neurones and mediates the release of luteinizing hormone (LH) and follicle stimulating hormone (FSH) from gonadotropic cells in the anterior pituitary. Their effects are mediated by binding to the gonadotropin-releasing hormone receptor 2 (GNRHR2) (Faurholm et al. 2001) which couples with the G protein alpha-q/11 subunit.