Fig. 8.

Differential effects of E₂, PPT, DPN, and G1 on relaxation of the KCl-precontracted aorta (A), carotid artery (B), mesenteric artery (C), and renal artery (D) of virgin versus pregnant rats. Endothelium-denuded segments of the thoracic aorta, carotid artery, mesenteric artery, and renal artery were precontracted with high KCl (96 mM) depolarizing solution to induce a Ca²⁺-dependent contractile response in vascular smooth muscle. Increasing concentrations (10⁻¹²–10⁻⁵ M) of E₂ (activator of all ERs), PPT (ERα agonist), DPN (ERβ agonist), or G1 (GPER agonist) were added, and the percent relaxation of KCl contraction was measured. Data represent means ± SE; n = 7–10 rats/group. *P < 0.05, pregnant vs. virgin rats.