ANTI-INFLAMMATORY EFFECT OF OXYTOCIN DURING A LPS CHALLENGE

SURKIN, PABLO NICOLÁS; CORREA, FERNANDO; DMYTRENKO, GANNA; FERNANDEZ-SOLARI, JAVIER; DE LAURENTIIS, ANDREA

Buenos Aires

Congreso; REUNION CONJUNTA DE SOCIEDADES DE BIOCIENCIAS; 2017

The hypothalamic-neurohypophysial system has recently emergedas an important component of the neuroendocrine-immune network,wherein the oxytocin (OXT)-secreting system, consisting of OXTmagnocellular neurons in the paraventricular (PVN) and supraopticnuclei (SON), plays an essential role. Lipopolysaccharide (LPS) administration activates the immune response and neurohypophysialhormones secretion. Our previous studies provided direct evidencefor the enhancement of OXT release from hypothalamus duringLPS-induced inflammation (J Neuroimmunol 221, 2010). Moreover,a cross-talk between OXT neurons and adjacent astrocytes determinesthe neuroimmunoendocrine final response. These findingsreveal that OXTnergic system could be a relevant component ofthe modulatory network of immune processes. Our objective wasto evaluate the possible anti-inflammatory role of OXT during anLPS challenge. Adult male Sprague-Dawley rats were treated withOXT via sc (10, 100 and 1000 mg/kg) or via icv (1mg/kg) or vehicle(CTROL) and after 15 min were injected with LPS (5mg/kg, ip).Additionally, microglial tumoral cells (BV-2) and primary astrocytescultures were pre-treated with OXT (0.1, 1, and 10 mM) for 15 minand then incubated with LPS (500 ng/ml) for 30 and 60 min. TNF-aconcentration in plasma and medium were determined by ELISA.ANOVA analysis indicated OXT immunomarcation of magnocellularneurons at PVN and SON was increased by LPS, suggesting theactivation of these neurons with an accumulation of OXT vesiclesin the hypothalamus. OXT (100 and 1000 mg/kg, sc) significantly(P