scholarly journals Cardioprotective Effect of Selective Estrogen Receptor Modulator Raloxifene Are Mediated by Heme Oxygenase in Estrogen-Deficient Rat

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Anikó Posa ◽  
Renáta Szabó ◽  
Krisztina Kupai ◽  
Anikó Magyariné Berkó ◽  
Médea Veszelka ◽  
...  

Estrogens and raloxifene (RAL) have beneficial effects on certain cardiovascular indices in postmenopausal women characterized by estrogen deficiency. Heme oxygenase (HO) activity is increased by 17β-estradiol (E2) and RAL in estrogen-deficient rat resulting in vasorelaxation mediated by carbon monoxide. We determined the expressions of HO in cardiac and aortic tissues after ovariectomy (OVX) and subsequent RAL or E2treatment. We investigated the effects of pharmacological inhibition of HO enzyme on the arginine vasopressin- (AVP-) induced blood pressure in vivo, the epinephrine- and phentolamine-induced electrocardiogram ST segment changes in vivo, and the myeloperoxidase (MPO) enzyme activity. When compared with intact females, OVX decreased the HO-1 and HO-2 expression, aggravated the electrocardiogram signs of heart ischemia and the blood pressure response to AVP, and increased the cardiac MPO. E2and RAL are largely protected against these negative impacts induced by OVX. The pharmacological inhibition of HO in E2- or RAL-treated OVX animals, however, restored the cardiovascular status close to that observed in nontreated OVX animals. The decreased expression of HO enzymes and the changes in blood pressure ischemia susceptibility and inflammatory state in OVX rat can be reverted by the administration of E2or RAL partly through its antioxidant and anti-inflammatory roles.

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Anikó Pósa ◽  
Krisztina Kupai ◽  
Rudolf Ménesi ◽  
Zita Szalai ◽  
Renáta Szabó ◽  
...  

We investigated the gender differences in heme-oxygenase (HO) enzyme, which produces endogenous vascular protective carbon monoxide (CO). We studied (1) the activity and expression of HO enzymes in the left ventricle (LV) and aorta, (2) basal increase in basal blood pressure provoked by arginine vasopressine (AVP)in vivo, (3) the heart perfusion induced by AVP, (4) the ST segment depression provoked by adrenaline and 30 seconds later phentolamine, and (5) the aorta ring contraction induced by AVP in female and male Wistar rats. We found that HO activity and the expression of HO-1 and HO-2 were increased in female rat aorta and LV. We demonstrated that the basal blood pressure and administration of AVP provoked blood pressure response are increased in the males; the female myocardium was less sensitive towards angina. Both differences could be aggravated by the inhibition of HO. The aorta rings were more susceptible towards vasoconstriction by AVP in males; isolated heart perfusion decrease was higher in males. The HO inhibition aggravated the heart perfusion in both sexes. In conclusion, the increased HO activity and expression in females might play a role in the sexual dimorphism of cardiovascular ischemia susceptibility during the reproductive age.


Nutrients ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 2305
Author(s):  
Wan-Ju Yeh ◽  
Jung Ko ◽  
Wei-Yi Cheng ◽  
Hsin-Yi Yang

High blood pressure is a crucial risk factor for many cardiovascular diseases, and a diet rich in whole-grain foods may modulate blood pressure. This study investigated the effects of dehulled adlay consumption on blood pressure in vivo. We initially fed spontaneous hypertensive rats diets without (SHR group) or with 12 or 24% dehulled adlay (SHR + LA and SHR + HA groups), and discovered that it could limit blood pressure increases over a 12-week experimental period. Although we found no significant changes in plasma, heart, and kidney angiotensin-converting enzyme activities, both adlay-consuming groups had lower endothelin-1 and creatinine concentrations than the SHR group; the SHR + HA group also had lower aspartate aminotransferase and uric acid levels than the SHR group did. We later recruited 23 participants with overweight and obesity, and they consumed 60 g of dehulled adlay daily for a six-week experimental period. At the end of the study, we observed a significant decrease in the group’s systolic blood pressure (SBP), and the change in SBP was even more evident in participants with high baseline SBP. In conclusion, our results suggested that daily intake of dehulled adlay had beneficial effects in blood-pressure management. Future studies may further clarify the possible underlying mechanisms for the consuming of dehulled adlay as a beneficial dietary approach for people at risk of hypertension.


1998 ◽  
Vol 275 (3) ◽  
pp. H760-H766 ◽  
Author(s):  
Leander V. Schuerch ◽  
Lilly M. Linder ◽  
Eric Grouzmann ◽  
Walter E. Haefeli

Human neuropeptide Y (hNPY) potentiates the postjunctional vasoconstrictor effects of α1-adrenoceptor agonists in animals and in human hand veins in vivo. We therefore hypothesized that such an interaction might also occur in the human arterial bed. With the present single-blind cross-over study in 12 healthy volunteers, the effect of subpressor doses of hNPY on the blood pressure response to α1-adrenoceptor stimulation was evaluated. Dose-response curves were constructed to intravenously infuse phenylephrine with and without coinfusion with two different doses of hNPY (1.4 and 14.3 pmol ⋅ kg−1 ⋅ min−1). Blood pressure, heart rate, and forearm blood flow were recorded, and plasma hNPY was determined. During infusion of the higher hNPY dose, which increased hNPY from 24.0 ± 12.0 to 495.1 ± 12.6 pmol/l, blood pressure curves were 2.4-fold shifted toward lower phenylephrine dose rates ( P < 0.001). Forearm vascular resistance showed a similar trend, whereas the counterregulatory decrease of heart rate was similar in both groups. In contrast, the lower hNPY dose rate producing a fourfold increase in hNPY concentrations did not modify the response to phenylephrine. This in vivo study in humans demonstrates that hNPY induced potentiating effects on α1-adrenergic constriction also in the systemic arterial circulation and suggests that circulating hNPY may participate in the control of vascular tone.


2014 ◽  
Vol 306 (10) ◽  
pp. F1179-F1189 ◽  
Author(s):  
Luuk te Riet ◽  
Mieke van den Heuvel ◽  
Carine J. Peutz-Kootstra ◽  
Joep H. M. van Esch ◽  
Richard van Veghel ◽  
...  

Dual renin-angiotensin system (RAS) blockade in diabetic nephropathy is no longer feasible because of the profit/side effect imbalance. (Pro)renin receptor [(P)RR] blockade with handle region peptide (HRP) has been reported to exert beneficial effects in various diabetic models in a RAS-independent manner. To what degree (P)RR blockade adds benefits on top of RAS blockade is still unknown. In the present study, we treated diabetic TGR(mREN2)27 rats, a well-established nephropathy model with high prorenin levels [allowing continuous (P)RR stimulation in vivo], with HRP on top of renin inhibition with aliskiren. Aliskiren alone lowered blood pressure and exerted renoprotective effects, as evidenced by reduced glomerulosclerosis, diuresis, proteinuria, albuminuria, and urinary aldosterone levels as well as diminished renal (P)RR and ANG II type 1 receptor expression. It also suppressed plasma and tissue RAS activity and suppressed cardiac atrial natriuretic peptide and brain natriuretic peptide expression. HRP, when given on top of aliskiren, did not alter the effects of renin inhibition on blood pressure, RAS activity, or aldosterone. However, it counteracted the beneficial effects of aliskiren in the kidney, induced hyperkalemia, and increased plasma plasminogen activator-inhibitor 1, renal cyclooxygenase-2, and cardiac collagen content. All these effects have been linked to (P)RR stimulation, suggesting that HRP might, in fact, act as a partial agonist. Therefore, the use of HRP on top of RAS blockade in diabetic nephropathy is not advisable.


Function ◽  
2021 ◽  
Author(s):  
Angela Troia ◽  
Russell H Knutsen ◽  
Carmen M Halabi ◽  
Daniela Malide ◽  
Zu Xi Yu ◽  
...  

Abstract Elastin insufficiency leads to the cardiovascular hallmarks of the contiguous gene deletion disorder, Williams-Beuren syndrome, including hypertension and vascular stiffness. Previous studies showed that Williams-Beuren syndrome deletions that extended to include the NCF1 gene were associated with lower blood pressure and reduced vascular stiffness. NCF1 encodes for p47phox, the regulatory component of the NOX1 NADPH oxidase complex, that generates reactive oxygen species in the vascular wall. Dihydroethidium and 8-hydroxyguanosine staining of mouse aortas confirmed that Eln heterozygotes (Eln+/-) had greater reactive oxygen species (ROS) levels than wild types (Eln+/+), a finding that was negated in vessels cultured without hemodynamic stressors. To analyze the Nox effect on elastin insufficiency, we utilized both genetic and chemical manipulations. Both Ncf1 haploinsufficiency (Ncf1+/-) and Nox1 insufficiency (Nox1-/y) decreased oxidative stress and systolic blood pressure in Eln+/- without modifying vascular structure. Chronic treatment with apocynin, a p47phox inhibitor, lowered systolic blood pressure in Eln+/-, but had no impact on Eln+/+ controls. In vivo dosing with phenylephrine produced an augmented blood pressure response in Eln+/- relative to Eln+/+, and genetic modifications or drug-based interventions that lower Nox1 expression reduce the hypercontractile response to phenylephrine in Eln+/- mice to Eln+/+ levels. These results indicate that the mechanical and structural differences caused by elastin insufficiency leading to oscillatory flow can perpetuate oxidative stress conditions which are linked to hypertension, and that by lowering the Nox1-mediated capacity for vascular ROS production, blood pressure differences can be normalized.


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