Sex differences in blood pressure response to continuous ANGII infusion: are sex hormones the only ones to blame for such differences?

DADAM F; CAEIRO X; VIVAS LM; RIVAROLA MA

Mar del Plata

Congreso; Reunión anual Conjunta SAIC SAFE SAB SAP; 2019

Evidence demonstrate that the pressorresponse to Ang II infusion is sexually dimorphic underphysiological and pathophysiological circumstances. But why domale and female show differences in rennin angiotensin system(RAS) activation and inhibition? Sex steroids can induceorganizational (long-lasting or permanent) effect during criticalperiods of development but can also impart (temporary orreversible) activational effects. Furthermore, males and femalesalso carry different sex chromosome complements (SCC:XY/XX)and thus are influenced throughout life by different genomes.Previous evidence demonstrates a modulatory effect of SCC inRAS receptor expression (brain and renal), as well as in the AngII sexually dimorphic bradycardic barroreflex and hypertensiveresponses. In the present study we evaluated the involvement ofSCC, organizational and activational hormone effect on changesin mean arterial pressure (MAP) in a 10 min Ang II infusionprotocol. For this purpose, we used gonadectomized (Gdx) miceof the "four core genotype" model, in which the effect of gonadalsex and SCC is dissociated, allowing comparisons of sexuallydimorphic traits between XX and XY females as well as in XX andXY males. For hormonal replacement experiments Gdx mice weredaily injected with ß-estradiol or testosterone propionate (2ug/g) for a 4 day period. The statistical analysis reveals aninteraction of SCC, organizational and activational hormonaleffect during Ang II infusion {F (7.39=2.60, p