Effects of gonadotrophin-releasing hormone outside the hypothalamic-pituitary-reproductive axis

Abstract

Gonadotrophin-releasing hormone (GnRH) is a hypothalamic decapeptide with an undisputed role as a primary regulator of gonadal function. It exerts this regulation by controlling the release of gonadotrophins. However, it is becoming apparent that GnRH may have a variety of other vital roles in normal physiology. A reconsideration of the potential widespread action that this traditional reproductive hormone exerts may lead to the generation of novel therapies and provide insight into seemingly incongruent outcomes from current treatments using GnRH analogues to combat diseases such as prostate cancer.

Figure 1

(A) Estrogen induced LH surge in the jugular blood and commensurate GnRH surges in the hypophyseal portal system and CSF of a ewe. For details of CSF harvesting, see (179). (B) GnRH receptor-immunoreactive neurons in the murine hippocampus. For details of immunocytochemistry, see (39). (C) Lipopolysaccharide, but not GnRH, induced temperature changes on the skin of the ewe ear. (D) Effect of GHRH and GnRH on GH secretion from an ovariectomized, progesterone treated ewe.