Decidualization results in the polarization of Ang‐(1‐7), Ang II, and ACE2 to the antimesometrial pole

Abstract

The two regions of the decidualized or pregnant uterine horn are programmed for different roles with the antimesometrial (AM) pole participating in implantation (embryo, oil), while the mesometrial (M) pole is fundamental for placenta blood flow. The present study was undertaken in order to understand the immunocytochemical (ICC) distribution of Ang II, Ang‐(1‐7), ACE and ACE2 in the non‐decidualized (ND) as compared to oil‐induced decidualized (OI) uterine horn of pseudopregnant rats. Ovariectomized adult rats were sensitized for the decidual cell reaction with steroid treatment (progesterone and 17‐β estradiol) and oil was injected into the left horn; the right horn served as control. For ICC, antibodies used were against Ang‐(1‐7) (1:25), Ang II (1:750), ACE2 (1:150), and ACE (1:25). In the ND horn, Ang‐(1‐7), ACE2, Ang II and ACE showed high expression in the glandular and luminal epithelium. Both Ang II and ACE were distributed throughout the ND horn, whereas Ang‐(1‐7) and ACE2 were predominately localized in the M end. In the decidualized horn, Ang II, Ang‐(1‐7) and ACE2 were localized more prominently at the antimesometrial (AM) pole; ACE was localized more at the M end. In conclusion, our studies show that the distribution of Ang II, Ang‐(1‐7) and ACE2 shifted to the AM pole with decidualization, with ACE shifting to the M. The differential expression of Ang II, Ang‐(1‐7) with ACE2 and not ACE in the AM pole of the decidualized horn favors the formation and action of Ang‐(1‐7) in the AM, an area which plays a prominent role in the implantation process. This research was supported by NHLBI PO1‐HL051952.