SEX CHROMOSOME COMPLEMENT EFFECT ON SEXUALLY DIMORPHIC BRAIN ANGIOTENSIN RECEPTORS EXPRESSION,

DADAM, FM; GODINO, A; MACCHIONE, AF; CAMBIASSO MJ; VIVAS, L.; CAEIRO XE

Foz de Iguazú

Congreso; 1st PanAmerican Congress of; 2014

The aim of this study was to define whether sex chromosome complement (SCC) may differentially modulate sex differences of mRNA brain expression of the Ang II and Ang-(1-7) receptors. For this purpose, we used the "four core genotypes" mouse model, in which the effect of gonadal sex and SCC is dissociated, allowing comparisons of sexually dimorphic traits between XX and XY females as well as in XX and XY males. Brains were collected from gonadectomized male (XX and XY) and female (XX and XY) mice and brain relative gene expression of AT1aR, AT2R, and MasR receptors were assessed using quantitative real time-PCR (n=6). Statistical analysis of the Subfornical Organ (SFO) data showed that, regardless of gonadal status, XY-SCC mice showed a greater AT1aR expression vs. those with XX-SCC {F(1,20)=4.38; p<0.05}. Furthermore, at the Area Postrema (AP) level, a SCC effect was evidenced for both AT1aR and MasR gene expression {F(1,20)=5.63; p<0.05 and F(1,20)=4,57; p<0.05 respectively}, showing an enhanced mRNA level of both AT1aR and AT1R/AT2R ratio in XY-mice associated with a decrease in MasR gene expression when compared to XX mice. These results demonstrate a SCC-modulatory action on angiotensinergic receptor expression with an enhanced mRNA expression of the vasodilatory arm in XX mice and an increased mRNA expression of the vasoconstrictor arm at the AP and SFO in XY mice.