ER‐α Receptors Have More Prominent Depressor Role On Vasoconstractile Sensitivity in Treated And Untreated‐Ovariectomized Rat Mesentery Artery

Abstract

Natural estrogens have cardioprotective effects in premenopausal women. Nuclear estrogen receptors mediate genomic effects of estrogens. G‐protein coupled estrogen receptors are also defined cardiovascular system and mediate rapid non‐genomic effects. The role of estrogen receptor ER‐α and ER‐β on vasculature system is not completely understood. In this study, we investigated the effects of ER‐α and β on α1‐adrenergic receptor mediated vasoconstraction in control (C), 16‐week ovariectomized (O) and 17‐β estradiol (E2) treatment ovariectomized‐rat (OE) mesentery arteries. Phe‐mediated concentration response curves (CRC) were obtained from C, O and OE groups in the presence and absence of non‐selective ER agonist E2 (0.1μM), selective ER‐α agonist PPT (0.1μM) and selective ER‐β agonist DPN (0.1μM). Phe‐mediated CRC shifted to right presence of PPT in C (pD2:6.32 vs pD2: 5.80), O (pD2:6.40 vs pD2: 5.79) and OE (pD2: 6.52 vs pD2:6.08) groups. After E2 incubation, Phe‐mediated CRC only shifted to right in C group (pD2:6.40; pD2: 5.80), but insignificantly shifted to right in O (pD2:6.40 vs pD2:6.13) and OE (6.52 vs. 6.21) groups. On the other hand, DPN incubation did not change Phe‐mediated CRC in all groups.In conclusion, ER‐α receptor mediated responsiveness have more prominent depressor effects on vasocontractile sensitivity in all group.