THE ONSET OF SODIUM APPETITE: INTERACTION BETWEEN ANGIOTENSINERGIC AND SEROTONERGIC SYSTEMS AND THE OSMORECEPTIVE CELLS INVOLVEMENT

PORCARI C; DADAM F; CAEIRO XE.; MECAWI, A; ANTUNES-RODRIGUES J.; VIVAS L.; GODINO A

BUENOS AIRES

Congreso; 2nd FALAN CONGRESS; 2016

SAN- FALAN

Our aim was to evaluate during the delay of sodium appetite (SA) appearance after sodium depletion (SD), gene expression changes of different components of angiotensin (ANG), serotonergic (5HT) and osmoreceptive systems previously involved in SA modulation.Wistar rats were SD using furosemide combined with low sodium diet, at 2 and 24 h later the animals were decapitated. Specific brain areas were submitted to RT-PCR of transient receptor potential vanilloid type-1 (TRPV1) that is activated during hypertonicity-evoked shrinking, ANG type 1 receptor (AT1a) and 5HT type 2C receptor (5HT2C).AT1a mRNA expression significantly increases by SD along subfornical organ (SFO), dorsal raphe nucleus (DRN), and anteroventral third ventricle + supraoptic nucleus (AV3V + SON) without temporal effect. SD significantly decreases the expression of 5HT2C in the lateral parabrachial nucleus (LPBN) and this reduction was higher at 24 h. The opposite pattern was observed in the 5HT2C of SFO with a significant higher level at 24 h after SD. TRPV1 mRNA expression showed a significant decrease along the AV3V + SON in the SD animals and the higher reduction was at 24 h.In sum, our results indicate that changes in 5HT2C gene expression at LPBN and SFO nuclei may modulate SA appearance. The decreased TRPV1 gene expression is probably associated with downregulation of these channels during hypotonicity states that may help sodium intake onset.