Ovarian Androgens Maintain High GnRH Neuron Firing Rate in Adult Prenatally-Androgenized Female Mice

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Changes in gonadotropin-releasing hormone (GnRH) release frequency from the brain help drive reproductive cycles. In polycystic ovary syndrome (PCOS), persistent high GnRH/luteinizing hormone (LH) frequency disrupts cycles and exacerbates hyperandrogenemia. Adult prenatally-androgenized (PNA) mice exhibit increased GnRH neuron firing rate, elevated ovarian androgens, and disrupted cycles, but before puberty, GnRH neuron activity is reduced in PNA mice compared with controls. We hypothesized that ovarian feedback mediates the age-dependent change in GnRH neuron firing rate in PNA vs control mice. Extracellular recordings of green fluorescent protein (GFP)-identified GnRH neurons were made 5 to 7 days after sham-surgery, ovariectomy (OVX), or, in adults, after OVX plus replacement of sub-male androgen levels with dihydrotestosterone implants (OVX + DHT). In 3-week-old mice, OVX did not affect GnRH neuron firing rate in either group. In adult controls, OVX increased GnRH neuron firing rate, which was further enhanced by DHT. In adult PNA mice, however, OVX decreased GnRH neuron firing rate, and DHT restored firing rate to sham-operated levels. In contrast to the differential effects of ovarian feedback on GnRH neuron firing rate, serum LH increased after OVX in both control and PNA mice and was not altered by DHT. Pituitary gene expression largely reflected changes expected with OVX, although in PNA but not control mice, DHT treatment increased Lhb expression. These results suggest prenatal androgen exposure programs marked changes in GnRH neuron regulation by homeostatic steroid feedback. PNA lowers GnRH neuron activity in low-steroid states (before puberty, OVX), and renders activity in adulthood dependent upon ongoing exposure to elevated ovarian androgens.

Medienart:

E-Artikel

Erscheinungsjahr:

2020

Erschienen:

2020

Enthalten in:

Zur Gesamtaufnahme - volume:161

Enthalten in:

Endocrinology - 161(2020), 1 vom: 01. Jan.

Sprache:

Englisch

Beteiligte Personen:

Dulka, Eden A [VerfasserIn]
Burger, Laura L [VerfasserIn]
Moenter, Suzanne M [VerfasserIn]

Links:

Volltext

Themen:

08J2K08A3Y
33515-09-2
Androgen
Androgens
Dihydrotestosterone
Gonadotropin-Releasing Hormone
Journal Article
Neuroendocrine
Polycystic ovary syndrome
Puberty

Anmerkungen:

Date Completed 10.02.2020

Date Revised 05.01.2021

published: Print

Citation Status MEDLINE

doi:

10.1210/endocr/bqz038

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM304760552