Hypothalamic-pituitary-testicular axis (HPT axis) (HPT axis)

The Hypothalamic-pituitary-testicular (HPT) axis is a complex neuroendocrine system responsible for regulating male reproductive function and secondary sexual characteristics (StatPearls, NBK532293). It begins with the pulsatile release of Gonadotropin-releasing hormone (GnRH) from the hypothalamus, which stimulates the anterior pituitary to secrete Luteinizing hormone (LH) and Follicle-stimulating hormone (FSH) (NIH, PMC6495291). LH acts on Leydig cells in the testes to produce testosterone, while FSH acts on Sertoli cells to support spermatogenesis. The system is tightly regulated by negative feedback loops, where testosterone and inhibin inhibit the secretion of GnRH and gonadotropins to maintain hormonal homeostasis. Dysregulation of this axis is central to conditions such as hypogonadism and is a primary target for therapies in prostate cancer and fertility management (PubMed, 28641925).

Other names

HPG axisMale reproductive axisHypothalamic-pituitary-gonadal axis (male)

Pharmacological modulation of the HPT axis involves the use of GnRH receptor agonists or antagonists to suppress gonadotropin release, or the administration of exogenous androgens and gonadotropin analogs to either replace deficient hormones or stimulate specific cellular responses in the testes.