Effects of a GABAB antagonist on hypothalamic KISS1 expression in neonatal mice.

BOURGUIGNON, NADIA SOLEDAD; BIZZOZZERO, MARIANNE; DI GIORGIO, NOELIA; LUX-LANTOS, VICTORIA ADELA

BUENOS AIRES

Congreso; ). XVIII Jornadas Anuales de la Sociedad Argentina de Biología.; 2016

We have previously shown that in neonatal female GABAB1KO mice, lacking functional GABAB receptors, Kiss1 mRNA expression in the arcuate nucleus (ARC) is significantly lower that in WT female littermates, abolishing the normal sex differences observed at this age (females > males). Here we aimed to establish whether pharmacological intervention immediately postnatally could mimic the differences in ARC Kiss1 expression. Neonatal Balb/c mice were subcutaneously injected with CGP55845 (CGP, 1 mg/kg, a GABAB antagonist) or saline from postnatal day 2 (PND2) to PND6±1, three times/day (8AM, 1PM, 6PM). Mice were sacrificed at 3PM (after two injections on that day). Brains were frozen and 400 μm slices were obtained on a cryostat. ARC and anteroventral periventricular nucleus (AVPV) were micropunched and Kiss1 mRNA expression was assesed by qPCR (control gene: Cyclophilin B). Serum and gonads were collected for hormonal measurements. CGP significantly decreased ARC Kiss1 expression in both sexes (AU: ♀-Sal: 4.7±1.7, ♀-CGP: 3.0±1.1, ♂-Sal: 1.1±0.2, ♂-CGP:0.5±0.1; CGP≠SAL: p