Effect of Pregnancy and Diabetes on Vascular Receptors for Angiotensin II

Abstract

Both gestation and diabetes mellitus (DM) are conditions associated with an increased participation of renin-angiotensin system (RAS) as well as with changes in the vascular response to angiotensin II (Ang II). We sought to establish the impact of gestational diabetes mellitus (GDM) on Ang II- induced vasoconstriction and its correlation with the expression of angiotensin II receptors (AT₁R, AT₂ R). Female Wistar rats, virgin, or on day 3 after mating, received randomly streptozotocin (STZ) 60 mg/kgor saline ip.Streptozotocin-treated animals developed hyperglycemia (25.6 ± 1.42 mM). Ang II-induced vasoconstriction was evaluated on isolated aortas with (e+) and without (e-) endothelium and the protein expression of AT₁R and AT₂R was measured by western blot. Gestational diabetes mellitus significantly increased vasoconstriction with respect to all the other groups. Changes were observed only on e+ vessels. Interestingly, GDM moved AT₁R: AT₂R balance towards AT₁ R, while both pregnancy and diabetes towards AT₂R expression. In conclusion, GDM increases the possibility of an hypertensive complication by an increased AT₁R expression.

Keywords:

• gestational diabetes
• AT₁
• AT₂ receptors
• endothelium

ACKNOWLEDGMENT

This research was partially supported by a Comision de Operacion y Fomento de Actividades Academicas (COFAA) grant.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.