Effects of eplerenone on expression and activity of aortic endothelial nitric oxide synthase in hypertensive rats induced by high-salt intake
10.3969/j.issn.1000-4718.2015.09.013
- VernacularTitle:依普利酮对高盐诱导的高血压大鼠主动脉内皮型一氧化氮合酶表达及活性的影响
- Author:
Qian ZHANG
;
Jing DING
;
Fei YANG
;
Shengnan WANG
;
Feng SU
;
Deqin LU
- Publication Type:Journal Article
- Keywords:
Hypertension;
High-salt diet;
Endothelial nitric oxide synthase;
Mineralocorticoid receptor
- From:
Chinese Journal of Pathophysiology
2015;(9):1606-1610
- CountryChina
- Language:Chinese
-
Abstract:
[ ABSTRACT] AIM:To explore the effects of eplerenone on the expression and activity of aortic endothelial nitric oxide synthase ( eNOS) in high salt-induced hypertensive rats .METHODS: Male Wistar rats (4 week old, weighting 50~60 g) were randomly divided into control group , high-salt diet group and eplerenone group .The rats in control group were fed with ordinary rodent animal diet , the rats in high-salt group and eplerenone group were exposed to 5%salt diet for 16 weeks and administrated with the same dosage of saline or eplerenone (40 mg? kg-1? d-1 ) by gavage for 4 weeks, re-spectively.Systolic blood pressure (SBP) was measured by tail-cuff every 2 weeks.The rats were sacrificed after 16 weeks and the thoracic aorta was collected .The aldosterone content in the aorta was measured by ELISA .The protein levels of mineralocorticoid receptor (MR) and eNOS were determined by Western blot.The activitie of constitutive NOS (cNOS) was measured by chemocolorimetry .The protein localization of eNOS , neuronal nitric oxide synthase ( nNOS) and MR was observed by immunohistochemistry .RESULTS: A process of 8-week high-salt diet increased SBP gradually .SBP in the rats exposure to high salt for 16 weeks was significantly higher than that in control group ( P<0.05 ) .After 4 weeks of eplerenone treatment, SBP in the rats was significantly lower than that before treatment (P<0.05).Compared with control group, the aldosterone content in the aorta were significantly increased in high-salt diet group and eplerenone group ( P<0.05), the expression level of MR also increased significantly (P<0.05).Compared with control group, both eNOS pro-tein expression (P<0.05) and cNOS activity in high-salt diet group were significantly decreased (P<0.05).The protein expression of eNOS as well as cNOS activity in aorta increased significantly in eplerenone group compared with high -salt diet group (P<0.05).CONCLUSION:Aldosterone content in aorta of high-salt-induced hypertensive rats increases signifi-cantly .Aldosterone attenuates the protein expression of eNOS and reduces the enzyme activity through the activation of min -eralocorticoid receptor .The selective mineralocorticoid receptor antagonist eplerenone enhances the protein expression of eNOS and its activity , thereby improves eNOS function .
