Hypothalamic-Pituitary-Ovarian (HPO) axis dysfunction lies central to the
pathophysiology of this condition. The cyclicity of the HPO axis is maintained by
rigorous feedback mechanisms–both positive and negative. In PCOS, altered
hypothalamic kisspeptin signaling culminates in increased LH secretion, leading to
increased androgen output from the ovarian theca cells and impaired FSH secretion,
leading to aberrant folliculogenesis. A number of factors may be responsible for this
hypothalamic-pituitary-ovarian disarray, like Anti-Mullerian Hormone (AMH), insulin,
Insulin-like Growth Factor- 1 and 2 (IGF-1 & IGF-2), leptin, galanin, etc. Also, various
neurotransmitters like opioid signaling, GABAergic, and glutamatergic transmission
may act in tandem with the causation of this endocrine disorder. Still, many questions
remain unanswered for which extensive research is being undertaken.
Keywords: Androgen, AMH, Estrogen, FSH, Feedback, Galanin, GABA, GnRH, Hyperandrogenism, HPO, Insulin, Kisspeptin, LH, Leptin, Neurons, Ovarian, Opioid, Progesterone, PCOS, Secretion.
