ABSTRACT
To compare global endothelial function assessed by pulse wave analysis (PWA) using the ratio of endothelium dependent vasodilatation (EDV) to endothelium independent vasodilatation (EIV) in patients with hypercholesterolemia and controls. 92 subjects [46 hypercholesterolemics, 46 controls] were studied at standardized conditions. Baseline augmentation index (AIx) was assessed followed by the administration of 0.5 mg sublingual nitroglycerine, an endothelium independent vasodilator. AIx was assessed and the maximum change in AIx after nitroglycerine was recorded as EIV. After a washout period of 30 minutes, 400 µg of inhaled salbutamol, an endothelium dependent vasodilator was administered. AIx was assessed again and the maximum change in AIx after salbutamol was recorded as EDV. Global endothelial function was calculated as EDV:EIV ratio. EDV and EIV in patients with hypercholesterolemia compared to controls were 2.97 ± 3.95 and 6.65 ± 3.80 (p<0.001); and 13.41 ± 4.57 and 15.88 ± 4.78 (p=0.01) respectively. EDV:EIV ratio was significantly reduced in patients with hypercholesterolemia compared to controls; 0.21 ± 0.38 and 0.44 ± 0.24 (p<0.001) respectively. EDV:EIV ratio was significantly reduced in patients with hypercholesterolemia compared to controls. PWA is a potential clinical tool to assess global endothelial function in patients with hypercholesterole
Subject(s)
Humans , Male , Female , Adult , Endothelium/metabolism , Pulse Wave Analysis/methods , Hypercholesterolemia , Patients , Vasodilator Agents/adverse effectsABSTRACT
Aims: We aimed in this study to investigate the mechanisms of the vasorelaxation effect caused by the anthocyanins-enriched extract of Odontonema strictum flowers. Study Design: Anthocyanins-enriched extract of Odontonema strictum flowers and vasorelaxantes activities of mice aortic rings. Place and Duration of Study: The flowers of Odontonema strictum (Nees) Kuntze (Acanthaceae) were collected in January 2015 at the “Institut de Recherche en Sciences de la Santé (IRSS)” experimental station in Ouagadougou. The experiments were conducted in October - November 2018 at the department of Medicine and Traditional Pharmacopeia-Pharmacy (MEPHATRA-PH)/IRSS. Methodology: The extract was enriched in anthocyanins using Amberlite XAD-7 non-ionic resin column. The vasorelaxant activity of anthocyanins-enriched extract of O. strictum flowers (OSF) was tested using isolated organ-chamber technique with mice aorta rings. Results: OSF showed concentration-dependent relaxant effects on mice endothelium intact or denuded aortic rings pre-contracted with U46619 (10-7 M) and KCl (80 mM). OSF induced relaxation in the mice aortic rings by stimulating smooth muscle cells. The vasorelaxant effect of OSF (10-1000 µg/mL) was similar in endothelium-intact and endothelium-denuded aortic rings. The maximum relaxant effect was 93.78 ± 4.69% and 92.30 ± 3.19% for endothelium-intact and endothelium-denuded aortic rings, respectively. Moreover, after incubation of the aorta rings with OSF (400 µg/mL) or vehicle (0.02% of DMSO) in PSS, OSF blocked the contraction through mechanism involving inhibition of CaCl2 and U46619 effect. Conclusions: The present study provides a pharmacological evidence for the antihypertensive medicinal use of Odontonema strictum by highlighting its vasorelaxant activity.
ABSTRACT
OBJECTIVE： To study the vasodilatory effect of oxysophocarpine （OSC） on isolated thoracic aortic rings of rats and its possible mechanism. METHODS： Thoracic aortic rings of rats were collected （called “vascular ring” for short）. Using K-H nutrient solution as blank control and the diastolic rate as index， the effects of different concentrations （0.2-1.0 mg/mL） of OSC on normal vascular rings in basal state， normal or endothelium-free vascular rings pre-contracted by norepinephrine （PE， 1×10－6 mol/L） were investigated. After pre-culturing normal thoracic aortic rings by nitric oxide synthase inhibitor L-nitro-arginine methyl ester（L-NAME）and cyclooxygenase inhibitor indomethacin（INDO），as well as pre-culturing endothelium-free vascular rings by potassium ion channel blocker BaCl2，tetraethylammonium（TEA）and 4-aminopyridine（4-AP）， the diastolic effects of OSC of different concentrations （0.2-1.0 mg/mL） on the above vascular rings were investigated by using the same method. RESULTS： Compared with blank control， there was no significant effects of different concentrations of OSC on the diastolic rate of normal vascular rings in basal state （P＞0.05）， but 0.4-1.0 mg/mL OSC could significantly improve the diastolic rate of normal or endothelium-free vascular rings pre-contracted by PE （P＜0.01）， in concentration-dependent manner. After preculturing with L-NAME， INDO， 4-AP and BaCl2， different concentrations of OSC had no significant effect on the diastolic rate of normal or endothelium-free vascular rings pre-contracted by PE （P＞0.05）. After pre-culturing with TEA and Gli， 0.4-1.0 mg/mL OSC could significantly reduce the diastolic rate of endothelium-free vas- cular rings pre-contracted by PE （P＜0.01）. CONCLUSIONS： OSC did not significantly dilate the thoracic aortic rings of rats in the basal state within the dose range （0.2-1.0 mg/mL）， but OSC of 0.4-1.0 mg/mL have significant diastolic effects on the normal or endothelium-free thoracic aortic rings of rats pre-contracted with PE. The mechanism of thoracic aortic rings dilation is endothelium-independent， which may be associated with receptor operational calcium channel，Ca2+-activated potassium channels and ATP-sensitive potassium channels.
ABSTRACT
The relaxant effect of the methyl ester of rosuvastatin was evaluated on aortic rings from male Wistar rats (250-300 g, 6 rats for each experimental group) with and without endothelium precontracted with 1.0 µM phenylephrine. The methyl ester presented a slightly greater potency than rosuvastatin in relaxing aortic rings, with log IC50 values of -6.88 and -6.07 M, respectively. Unlike rosuvastatin, the effect of its methyl ester was endothelium-independent. Pretreatment with 10 µM indomethacin did not inhibit, and pretreatment with 1 mM mevalonate only modestly inhibited the relaxant effect of the methyl ester. Nω-nitro-L-arginine methyl ester (L-NAME, 10 µM), the selective nitric oxide-2 (NO-2) inhibitor 1400 W (10 µM), tetraethylammonium (TEA, 10 mM), and cycloheximide (10 µM) partially inhibited the relaxant effect of the methyl ester on endothelium-denuded aortic rings. However, the combination of TEA plus either L-NAME or cycloheximide completely inhibited the relaxant effect. Inducible NO synthase (NOS-2) was only present in endothelium-denuded aortic rings, as demonstrated by immunoblot with methyl ester-treated rings. In conclusion, whereas rosuvastatin was associated with a relaxant effect dependent on endothelium and hydroxymethylglutaryl coenzyme A reductase in rat aorta, the methyl ester of rosuvastatin exhibited an endothelium-independent and only slightly hydroxymethylglutaryl coenzyme A reductase-dependent relaxant effect. Both NO produced by NOS-2 and K+ channels are involved in the relaxant effect of the methyl ester of rosuvastatin.