Menopause and the human hypothalamus: evidence for the role of kisspeptin/neurokinin B neurons in the regulation of estrogen negative feedback.
Rance. Naomi E NE
Key Findings
- Menopause triggers hypertrophy of kisspeptin/NKB neurons in the hypothalamus
- Increased GnRH secretion from these neurons drives higher gonadotropin levels in postmenopausal women
- Similar neuronal changes occur in animal models after ovariectomy, indicating a compensatory response to loss of ovarian hormones
Practical Outcomes
- Knowing that kisspeptin pathways are central to menopause hormone changes may help future drug or supplement development, but currently there’s no actionable protocol or dosage for biohackers to apply.
Summary
The study shows that after menopause, the brain’s hormone‑control center stays active and the kisspeptin‑producing neurons get bigger, which likely drives the rise in reproductive hormones when the ovaries stop working. This explains why menopause causes high GnRH and gonadotropin levels, but it doesn’t give a direct way to use kisspeptin‑10 for health benefits.
Abstract
Menopause is characterized by depletion of ovarian follicles, a reduction of ovarian hormones to castrate levels and elevated levels of serum gonadotropins. Rather than degenerating, the reproductive neuroendocrine axis in postmenopausal women is intact and responds robustly to the removal of ovarian hormones. Studies in both human and non-human primates provide evidence that the gonadotropin hypersecretion in postmenopausal women is secondary to increased gonadotropin-releasing hormone (GnRH) secretion from the hypothalamus. In addition, menopause is accompanied by hypertrophy of neurons in the infundibular (arcuate) nucleus expressing KiSS-1, neurokinin B (NKB), substance P, dynorphin and estrogen receptor alpha (ERalpha) mRNA. Ovariectomy in experimental animals induces nearly identical findings, providing evidence that these changes are a compensatory response to ovarian failure. The anatomical site of the hypertrophied neurons, as well as the extensive data implicating kisspeptin, NKB and dynorphin in the regulation of GnRH secretion, provide compelling evidence that these neurons are part of the neural network responsible for the increased levels of serum gonadotropins in postmenopausal women. We propose that neurons expressing KiSS-1, NKB, substance P, dynorphin and ERalpha mRNA in the infundibular nucleus play an important role in sex-steroid feedback on gonadotropin secretion in the human.
Study Information
pubmed
2008
2008-05-28T00:00:00.000Z
10.1016/j.peptides.2008.05.016
228
110