| Title | Impact of 17-beta Estradiol Replacement on Vascular Responsiveness in Ovariectomized Diabetic Rats. | | Author(s) | Ceylan-Isik AF, Erdogan-Tulmac OB, Ari N, Ozansoy G, Ren J | | Institution | Ankara University Faculty of Pharmacy Department of Pharmacology, Ankara, Turkey. | | Source | Clin Exp Pharmacol Physiol 2009 Jun 29. | | Abstract | 1. Women with functional ovaries display a gender advantage in the prevalence of cardiovascular diseases. However, whether this gender bias pertains in diabetes is debatable. 2. This study was designed to examine the effect of 17beta-estradiol (E(2)) on vascular responsiveness in normal and diabetic (DIA) ovariectomized (OVX) rats. Aged-matched female rats were divided into 4 groups including OVX, OVX+E(2), OVX+DIA and OVX+DIA+E(2). Bilateral ovariectomy was performed and streptozotocin was used to induce experimental diabetes. E(2) treatment was applied for 8 weeks. 3. Although E(2) treatment had no effect on blood glucose levels in normal and diabetic OVX rats, it significantly reduced systolic blood pressure and prevented diabetes-induced loss in body weight gain. Concentration-dependent vasoconstriction of KCl and phenylephrine (PE) was significantly attenuated following E(2) treatment in both normal and DIA groups. The SERCA inhibitor thapsigargin and the Ca(2+) channel blocker nifedipine inhibited the transient vasoconstriction of PE in all groups. The constrictive effect of PE was increased by the NOS inhibitor L-NAME while it was reduced by superoxide dismutase (SOD) and the cyclooxygenase inhibitor indomethacin in all groups. Acetylcholine (Ach) response indicates that a reduced endothelium-dependent relaxation in non-E(2)-treated groups. Relaxation responses to ACh were increased by SOD and indomethacin, while it was reduced by L-NAME in all groups. There is no difference among all four groups in the relaxation responses to sodium nitroprusside. 4. Our results suggest that estrogen treatment has beneficial effects on vascular function in both diabetic and non-diabetic OVX rats due to Ca(2+) regulation and antioxidation. | | Language | ENG | | Pub Type(s) | JOURNAL ARTICLE
| | PubMed ID | 19566816 |
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