Infertility in GABAB1KO female mice: possible role of brain estrogens and hypothalamic response to kisspeptin.

DI GIORGIO N P; LOPEZ P V; BOURGUIGNON N S; SEMAAN S J; BETTLER B; KAUFFMAN A S; LIBERTUN C; LUX LANTOS V

Chicago

Congreso; 16th International congress of endocrinology ? The Endocrine Society´s 96th Annual Meeting & Expo.; 2014

Adult GABAB1KO (KO) female mice, which lack functional GABAB receptors, have altered cyclicity, increased GnRH pulsatility and infertility. Moreover, Gnrh1 and Gad1 (enzyme that synthesizes GABA) mRNA expressions are altered in KO hypothalami (H), especially in anterior H (AH) and are not due to serum estrogen levels. However, Kiss1 mRNA in AVPV/PeN and ARC is similar to adult WT females. Here we evaluated the possible role of brain estrogens in these effects, in WT and KO adult mice from both sexes. We also evaluated GnRH pulsatility in the presence of Kiss1r agonist and/or antagonist in E2-treated ovariectomized adult mice. We determined aromatase (Cyp19a1) and alpha estrogen receptor (Er1) mRNA expressions in AH and medial basal H (MBH) and progesterone receptor (Pgr) mRNA expression in micropunches of AVPV/PeN and ARC by qPCR in WT and KO males and females (in estrus). For in vitro GnRH pulsatility studies, adult WT and KO females were ovariectomized and treated with a single dose of estradiol valerate (sc, 10µg/kg). Seven days post-ovariectomy, they were sacrificed. H were collected and incubated in 250 µl of Krebs-Ringer bicarbonate buffer with 4.5 mg/ml glucose and 16 mM HEPES at 37°C for 7.5h. Treatments: control (CT), Kiss-10 (agonist, 1.10-7M), Kiss-234 (antagonist, 1.10-7M) and Kiss-10+Kiss-234 (1.10-7M each). Media were collected at 9-min intervals and replaced with fresh medium with/without stimuli. Secreted GnRH was measured by RIA. Cyp19a1 was higher in males vs females (p