Displaying publications 81 - 100 of 216 in total

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  1. Lowering of lipid composition in aorta of guinea pigs by Curcuma domestica
    Ahmad-Raus RR, Abdul-Latif ES, Mohammad JJ
    BMC Complement Altern Med, 2001;1:6.
    PMID: 11495637
    A short-term study was carried out using guinea pigs to determine the effects of Curcuma domestica on lipid composition in the serum and aorta.
    Matched MeSH terms: Aorta/chemistry
  2. Fulltext Characterization and in vivo study of decellularized aortic scaffolds using closed sonication system
    Hazwani A, Sha'Ban M, Azhim A
    Organogenesis, 2019;15(4):120-136.
    PMID: 31495272 DOI: 10.1080/15476278.2019.1656997
    Extracellular matrix (ECM) based bioscaffolds prepared by decellularization has increasingly emerged in tissue engineering application because it has structural, biochemical, and biomechanical cues that have dramatic effects upon cell behaviors. Therefore, we developed a closed sonication decellularization system to prepare ideal bioscaffolds with minimal adverse effects on the ECM. The decellularization was achieved at 170 kHz of ultrasound frequency in 0.1% and 2% Sodium Dodecyl Sulphate (SDS) solution for 10 hours. The immersion treatment as control was performed to compare the decellularization efficiency with our system. Cell removal and ECM structure were determined by histological staining and biochemical assay. Biomechanical properties were investigated by the indentation testing to test the stiffness, a residual force and compression of bioscaffolds. Additionally, in vivo implantation was performed in rat to investigate host tissue response. Compared to native tissues, histological staining and biochemical assay confirm the absence of cellularity with preservation of ECM structure. Moreover, sonication treatment has not affected the stiffness [N/mm] and a residual force [N] of the aortic scaffolds except for compression [%] which 2% SDS significantly decreased compared to native tissues showing higher SDS has a detrimental effect on ECM structure. Finally, minimal inflammatory response was observed after 1 and 5 weeks of implantation. This study reported that the novelty of our developed closed sonication system to prepare ideal bioscaffolds for tissue engineering applications.
    Matched MeSH terms: Aorta*
  3. A rare complication of myocardial ischaemia following single-stage repair in a case of Berry syndrome
    Duyen MD, Haranal MY, Dillon J, Sivalingam S
    Interact Cardiovasc Thorac Surg, 2020 10 01;31(4):576-577.
    PMID: 32772077 DOI: 10.1093/icvts/ivaa126
    Berry syndrome is a rare congenital cardiac lesion consisting of a distal aortopulmonary window, the aortic origin of the right pulmonary artery (PA), intact ventricular septum and an interrupted or hypoplastic aortic arch. Different repair techniques have been described in the literature. We report a case of Berry syndrome, in whom myocardial ischaemia developed following direct implantation of the right PA to the main PA, which was resolved using an interposition tube graft.
    Matched MeSH terms: Aorta, Thoracic/surgery*
  4. Circumflex aorta: An uncharted territory
    Haranal M, Srimurugan B, Sivalingam S
    Asian Cardiovasc Thorac Ann, 2021 May 06.
    PMID: 33957784 DOI: 10.1177/02184923211015092
    BACKGROUND: Vascular rings are aortic arch anomalies with a spectrum of manifestations ranging from asymptomatic lesions detected incidentally to an acute presentation secondary to tracheo-esophageal compression. Circumflex retro-esophageal aortic arch is an extreme form of true vascular ring. It remains an uncharted territory to many surgeons.

    METHODS: A comprehensive search of peer reviewed journals was completed based on the key words, "Circumflex aorta," "Circumflex retro-esophageal aorta" and "circumflex arch" using Google scholar, Scholars Portal Journals and PubMed. The reference section for each article found was searched to obtain additional articles. Literature on the circumflex aorta was reviewed starting from the embryogenesis to the latest management strategies.

    RESULTS: Right circumflex aorta is more prevalent compared to left circumflex aorta. It can occur in isolation or in association with other intracardiac lesions. Mainly presents in children, however reported in adults too. The presentation may vary from asymptomatic lesion to acute respiratory distress secondary to airway compression. Computerized tomography (CT) and magnetic resonance imaging (MRI) are important tools in delineating the vascular anatomy. Aortic uncrossing is the definitive procedure. However, the role of concomitant tracheobronchopexy is emerging. Native tissue-to-tissue anastomosis is commonly preferred, but cases of extra-anatomic grafts are reported.

    CONCLUSION: Circumflex aorta is amenable to complete repair. Preoperative delineation of anatomy is important for successful surgical outcome. Division of the retro-esophageal segment is crucial in relieving the compressive symptoms. In addition, tracheobronchopexy is helpful in addressing residual tracheomalacia but this accounts for a high-risk surgery.

    Matched MeSH terms: Aorta; Aorta, Thoracic
  5. Characterizing the mechanisms of insulin vasodilatation of normal and streptozotocin-induced diabetic rat aorta
    Subramaniam G, Achike FI, Mustafa MR
    J Cardiovasc Pharmacol, 2009 Apr;53(4):333-40.
    PMID: 19295443 DOI: 10.1097/FJC.0b013e31819fd4a7
    The mechanism by which insulin causes vasodilatation remains unclear, so we explored this in aortic rings from normal Wistar Kyoto and streptozotocin-induced diabetic rats. Insulin-induced relaxation of phenylephrine-contracted [endothelium (ED) intact or denuded] aortic rings was recorded in the presence or absence of various drug probes. Insulin relaxant effect was more in ED-intact than in-denuded tissues from normal or diabetic rats. l-NAME or methylene blue partially inhibited insulin effect in ED-intact but not the ED-denuded tissues, whereas indomethacin (cyclooxygenase inhibitor) had no effect on any of the tissues, indicating that insulin induces relaxation by ED-dependent and -independent mechanisms, the former via the NOS-cyclic guanosine monophosphate but not the cyclooxygenase pathway. The voltage-dependent K channel (KV) blocker (4-aminopyridine) inhibited insulin action in all the tissues (normal or diabetic, with or without ED), whereas the selective BKCa blocker, tetraethylammonium, inhibited it in normal (ED intact or denuded) but not in diabetic tissues, indicating that KV mediates insulin action in normal and diabetic tissues, whereas the BKCa mediates it only in normal tissues, with possible pathophysiologic absence in diabetic tissues. The inward rectifier K channel (Kir) blocker (barium chloride) significantly inhibited insulin effect only in ED-intact or -denuded diabetic tissues, whereas the KATP channel blocker, glibenclamide, inhibited it only in the ED-denuded diabetic tissues, suggesting that Kir channels mediate insulin-induced relaxation in ED-intact or -denuded diabetic tissues, whereas the KATP channel mediates it in ED-denuded diabetic tissues. All the agents combined did not abolish insulin action, suggestive of a direct vasodilatory effect. In conclusion, insulin causes vasodilatation in normal and diabetic tissues via ED-dependent and -independent mechanisms differentially modulated by K channels, some of which functions are altered in diabetes and thus are potential therapeutic targets.
    Matched MeSH terms: Aorta, Thoracic/drug effects*
  6. Mechanisms of action of Panax notoginseng ethanolic extract for its vasodilatory effects and partial characterization of vasoactive compounds
    Loh YC, Tan CS, Ch'ng YS, Ng CH, Yeap ZQ, Yam MF
    Hypertens Res, 2019 02;42(2):182-194.
    PMID: 30464217 DOI: 10.1038/s41440-018-0139-9
    Panax notoginseng is the most valuable medicinal plant and has been used clinically for more than two thousand years to treat various diseases, including hypertension. Previous studies claimed that different isolated compounds from P. notoginseng are involved in different pathways for vasodilation. It is strongly believed that these vasodilating compounds might act synergistically in contributing vasodilatory effects via holistic signaling pathways. The present study aims to evaluate the vasodilatory effect and mechanism of action employed by the crude extract of P. notoginseng. The fingerprint of P. notoginseng was developed using tri-step FTIR and HPTLC. The contents of Rg1 and Rb1 in the active extract (PN95) were further quantified via HPTLC. The vasodilatory effect of PN95 was evaluated using an in vitro aortic ring model. The results showed that PN95 contains a high amount of Rg1 and Rb1, 25.9 and 13.6%, respectively. The vasodilatory effect of PN95 was elicited via the NO/sGC/cGMP and β2-adrenergic receptors pathways. Furthermore, PN95 could manage vascular tone by regulating action potentials via potassium and both VOCC and IP3R pathways. The results obtained fulfilled the expected outcome where the PN95 employed more signaling pathways than any of the single active compounds; hence, the holistic therapeutic effect could be achieved and would more easily translate to applications for the treatment of human diseases.
    Matched MeSH terms: Aorta/drug effects*
  7. Right aortic arch with isolation of the left subclavian artery: a rare association with airway obstruction
    Yubbu P, Latiff HA, Adam Abbaker AM
    Cardiol Young, 2017 Apr;27(3):613-616.
    PMID: 27817752 DOI: 10.1017/S1047951116001840
    We present two interesting cases of isolated left subclavian artery from the pulmonary artery with symptoms of upper airway obstruction. The first patient had tetralogy of Fallot, pulmonary artery sling, bilateral superior caval veins, and left bronchial isomerism, suggesting heterotaxy syndrome. The second patient had a right aortic arch, isolated left subclavian artery, and bilateral arterial ducts. These two cases are interesting because of their rarity and uncommon presentation.
    Matched MeSH terms: Aorta, Thoracic/abnormalities*
  8. Fulltext Primary arteritis of aorta causing renal artery stenosis and hypertension
    Danaraj TJ, Wong HO, Thomas MA
    Br Heart J, 1963 Mar;25(2):153-65.
    PMID: 14024854
    The evidence presented by the nine cases described in this paper indicates that primary arteritis of the aorta is a single clinico-pathological entity of which Takayashu's syndrome is a part. Different segments of the aorta may be affected resulting in a variety of symptom complexes. In this series, the mode of presentation was hypertension consequent on renal artery stenosis. Early diagnosis is important and surgical treatment is indicated to relieve the hypertension which carries an immediately serious prognosis.
    Matched MeSH terms: Aorta*; Aortic Diseases*
  9. Fulltext Protection by tocotrienols against hypercholesterolaemia and atheroma.
    Teoh MK, Chong JMK, Mohamed J, Phang KS
    Med J Malaysia, 1994 Sep;49(3):255-62.
    PMID: 7845276
    Antioxidants such as tocotrienols may protect against atherosclerosis since tissue injury from free radicals is a final common pathway of damage in arterial disease. In this study, the effects of tocotrienols on serum cholesterol, lipid peroxides, and aorta atheroma were assessed in rabbits fed an atherogenic diet for 12 weeks. Tocotrienols were more effective than tocopherols in preventing increases in serum LDL (p = 0.03) and total cholesterol (p = 0.008) levels in the cholesterol-fed rabbits. Elevation of serum lipid peroxides was effectively suppressed by tocotrienols (p = 0.01). Both tocopherols and tocotrienols offered significant protection against atheroma in the rabbit aorta, but tocotrienols had a stronger hypolipidaemic effect.
    Comment in: Pathmanathan R, Wong KT. Protection by tocotrienols against hypercholesterolaemia and atheroma. Med J Malaysia. 1995 Mar;50(1):117
    Matched MeSH terms: Aorta/pathology
  10. A case of missed blunt traumatic aortic injury (BTAI)
    Nik Azlan NM, Rossman H
    Med J Malaysia, 2017 06;72(3):193-194.
    PMID: 28733569 MyJurnal
    We are reporting a case of missed blunt traumatic aortic injury (BTAI). A 28 year male presented with chest pain following a motor vehicle accident. He was discharged following normal clinical signs and chest radiograph. The following day he complained of lower limb weakness. Traumatic aortic dissection was revealed via computer tomography (CT) of the thorax. BTAI cannot be ruled out with normal clinical signs and chest radiograph alone. CT thorax is mandatory to rule out BTAI in high impact chest injury.
    Matched MeSH terms: Aorta/injuries*
  11. Effect of alpha lipoic acid on oxidative stress and vascular wall of diabetic rats
    Balkis Budin S, Othman F, Louis SR, Abu Bakar M, Radzi M, Osman K, et al.
    Rom J Morphol Embryol, 2009;50(1):23-30.
    PMID: 19221642
    PREMISES AND OBJECTIVES: Antioxidant plays an important role in preventing the progression of diabetes mellitus (DM) complications. The aim of the present study was to investigate the effect of alpha lipoic acid (ALA) supplementation on plasma lipid, oxidative stress and vascular changes in diabetic rats.
    Matched MeSH terms: Aorta, Thoracic/drug effects; Aorta, Thoracic/pathology; Aorta, Thoracic/physiopathology*; Aorta, Thoracic/ultrastructure
  12. Mechanisms underlining gender differences in Phenylephrine contraction of normoglycaemic and short-term Streptozotocin-induced diabetic WKY rat aorta
    Aloysius UI, Achike FI, Mustafa MR
    Vascul. Pharmacol., 2012 Sep-Oct;57(2-4):81-90.
    PMID: 22172524 DOI: 10.1016/j.vph.2011.11.009
    The female gender reduces the risk, but succumbs more to cardiovascular disease. The hypothesis that short-term (8weeks) Streptozotocin-induced diabetes could produce greater female than male vascular tissue reactivity and the mechanistic basis were explored. Aortic ring responses to Phenylephrine were examined in age- and sex-matched normoglycaemic/diabetic rats. The normoglycaemic male tissue contracted significantly more than the normoglycaemic female and the male/female diabetic tissues. Endothelial-denudation, l-NAME or MB reversed these differences suggesting an EDNO-cGMP dependence. 17β-oestradiol exerted relaxant effect on all endothelium-denuded (and normoglycaemic endothelium-intact male) tissues, but not endothelium-intact normoglycaemic female. The greater male tissue contraction is attributable to absent 17β-oestradiol-modulated relaxation. Indomethacin blockade of COX attenuated male normoglycaemic and female diabetic tissue contraction (both reversed by l-NAME), but augmented diabetic male tissue contraction. These data are consistent with the raised contractile TXA(2) and PGE(2) in normoglycaemic male and diabetic female tissues, and the relaxant PGI(2) in diabetic male (and female). The higher levels of PGI(2) in the normoglycaemic and diabetic female perhaps explain their greater relaxant response to Acetylcholine compared to the respective male. In conclusion, there is an endothelium-dependent gender difference in the effect of short term diabetes on vascular tissue reactivity which is COX mediated.
    Matched MeSH terms: Aorta, Thoracic/drug effects*; Aorta, Thoracic/metabolism
  13. Fulltext Oil palm vegetation liquor: a new source of phenolic bioactives
    Sambanthamurthi R, Tan Y, Sundram K, Abeywardena M, Sambandan TG, Rha C, et al.
    Br J Nutr, 2011 Dec;106(11):1655-63.
    PMID: 21736792 DOI: 10.1017/S0007114511002121
    Waste from agricultural products represents a disposal liability, which needs to be addressed. Palm oil is the most widely traded edible oil globally, and its production generates 85 million tons of aqueous by-products annually. This aqueous stream is rich in phenolic antioxidants, which were investigated for their composition and potential in vitro biological activity. We have identified three isomers of caffeoylshikimic acid as major components of oil palm phenolics (OPP). The 2,2-diphenyl-1-picrylhydrazyl assay confirmed potent free radical scavenging activity. To test for possible cardioprotective effects of OPP, we carried out in vitro LDL oxidation studies as well as ex vivo aortic ring and mesenteric vascular bed relaxation measurements. We found that OPP inhibited the Cu-mediated oxidation of human LDL. OPP also promoted vascular relaxation in both isolated aortic rings and perfused mesenteric vascular beds pre-contracted with noradrenaline. To rule out developmental toxicity, we performed teratological studies on rats up to the third generation and did not find any congenital anomalies. Thus, these initial studies suggest that OPP is safe and may have a protective role against free radical damage, LDL oxidation and its attendant negative effects, as well as vascular constriction in mitigating atherosclerosis. Oil palm vegetation liquor thus represents a new source of phenolic bioactives.
    Matched MeSH terms: Aorta/drug effects; Aorta/physiology
  14. Fulltext A detailed microscopic study of the changes in the aorta of experimental model of postmenopausal rats fed with repeatedly heated palm oil
    Adam SK, Das S, Jaarin K
    Int J Exp Pathol, 2009 Jun;90(3):321-7.
    PMID: 19563614 DOI: 10.1111/j.1365-2613.2009.00658.x
    Hypercholesterolaemia, increase in lipid peroxidation and hyperhomocysteinaemia may contribute to the pathogenesis of atherosclerosis. This study was performed to examine the effects of repeatedly heated palm oil mixed with 2% cholesterol diet on atherosclerosis in oestrogen-deficient postmenopausal rats. Ovariectomy causes disruption of tunica intima layer of the rat aorta simulating a postmenopausal condition in females. Twenty-four ovariectomized female Sprague-Dawley rats were divided into four groups. The control group received 2% cholesterol diet without palm oil. A diet with 2% cholesterol content fortified with fresh, once-heated and five-times-heated palm oil was given to the other treatment groups. The rats were sacrificed at the end of 4 months of study and the aortic arch tissue was processed for histomorphometry and electron microscopy. On observation, there was disruption of the intimal layer of the ovariectomized rat aorta. There was no obvious ultrastructural change in the aorta of the rats fed with fresh palm oil. The ultrastructural changes were minimal with once-heated palm oil, in which there was a focal disruption of the endothelial layer. The focal disruption was more pronounced with five-times-heated palm oil. The results of this study show that the ingestion of fresh palm oil may have a protective effect on the aorta but such a protective action may be lost when the palm oil is repeatedly heated. The study may be clinically important for all postmenopausal women who are susceptible to atherosclerosis.
    Matched MeSH terms: Aorta, Thoracic/drug effects*; Aorta, Thoracic/ultrastructure
  15. Giant cell myocarditis with cardiac tamponade: a rare combination
    Murty OP
    Am J Forensic Med Pathol, 2008 Sep;29(3):245-8.
    PMID: 18725781 DOI: 10.1097/PAF.0b013e318183d55f
    Giant cell myocarditis (GCM) is a rare but fatal disease of idiopathic origin. It results in focal necrosis of myocardium. This is a case report of middle aged Malaysian Indian female who died due to cardiac tamponade due to rupture myocardium and tear in the root of aorta. On naked eye examination, it simply resembled as recent as well as old fibrotic areas of myocardial infarction. She was clinically diagnosed as a case of obstructive cardiomyopathy with atrioventricular block, and was on pace maker. There was subendocardial fibrosis and left ventricular transmural infarction in the left ventricle. On histopathology, this was diagnosed as GCM, there were widespread areas of inflammatory cellular infiltration within the myocardium with multinucleated giant cells and granulomas interspersed with lymphocytes. Microscopic field showed up to 10 multinucleated giant cells. In this case, there were focal areas at multiple locations and caused uneven thickness in the left ventricle wall. Idiopathic GCM is very rare and causation of hemopericardium is the unique feature of this case. In this case the direct link of GCM with aortitis and rupture of left ventricle wall resulting in hemopericardium is shown. This case is documented through macroscopic as well as microscopic photographs in H&E, Ziel-Nelson, and GMS staining.
    Matched MeSH terms: Aorta/injuries; Aorta/pathology
  16. Alpha lipoic acid possess dual antioxidant and lipid lowering properties in atherosclerotic-induced New Zealand White rabbit
    Zulkhairi A, Zaiton Z, Jamaluddin M, Sharida F, Mohd TH, Hasnah B, et al.
    Biomed Pharmacother, 2008 Dec;62(10):716-22.
    PMID: 18538528 DOI: 10.1016/j.biopha.2006.12.003
    There is accumulating data demonstrated hypercholesterolemia and oxidative stress play an important role in the development of atherosclerosis. In the present study, a protective activity of alpha-lipoic acid; a metabolic antioxidant in hypercholesterolemic-induced animals was investigated. Eighteen adult male New Zealand White (NZW) rabbit were segregated into three groups labelled as group K, AT and ALA (n=6). While group K was fed with normal chow and acted as a control, the rest fed with 100 g/head/day with 1% high cholesterol diet to induce hypercholesterolemia. 4.2 mg/body weight of alpha lipoic acid was supplemented daily to the ALA group. Drinking water was given ad-libitum. The study was designed for 10 weeks. Blood sampling was taken from the ear lobe vein at the beginning of the study, week 5 and week 10 and plasma was prepared for lipid profile estimation and microsomal lipid peroxidation index indicated with malondialdehyde (MDA) formation. Animals were sacrificed at the end of the study and the aortas were excised for intimal lesion analysis. The results showed a significant reduction of lipid peroxidation index indicated with low MDA level (p<0.05) in ALA group compared to that of the AT group. The blood total cholesterol (TCHOL) and low density lipoprotein (LDL) levels were found to be significantly low in ALA group compared to that of the AT group (p<0.05). Histomorphometric intimal lesion analysis of the aorta showing less of atheromatous plaque formation in alpha lipoic acid supplemented group (p<0.05) compared to that of AT group. These findings suggested that apart from its antioxidant activity, alpha lipoic acid may also posses a lipid lowering effect indicated with low plasma TCHOL and LDL levels and reduced the athero-lesion formation in rabbits fed a high cholesterol diet.
    Matched MeSH terms: Aorta/metabolism; Aorta/pathology
  17. Baicalein impairs vascular tone in normal rat aortas: role of superoxide anions
    Machha A, Achike FI, Mohd MA, Mustafa MR
    Eur J Pharmacol, 2007 Jun 22;565(1-3):144-50.
    PMID: 17442302
    Acute exposure to the flavonoid baicalein inhibited endothelium-dependent relaxation in physiological arteries, although the mechanisms are not fully understood. We investigated the effect of baicalein on vascular tone in Wistar-Kyoto (WKY) rat isolated aortic rings in the presence and absence of oxidative stress to further determine the underlying mechanisms. Exposure to baicalein (10 microM) completely abolished endothelium-dependent relaxation induced by acetylcholine and attenuated significantly the endothelium-independent relaxation induced by sodium nitroprusside. Baicalein, similar to Nomega-nitro-L-arginine methyl ester (L-NAME, 10 microM), potentiated significantly the contractile response of aortic rings to alpha1-adrenoceptor agonist phenylephrine. In the presence of L-NAME the baicalein effect on phenylphrine contraction or acetylcholine relaxation was unaltered, suggesting that these effects of baicalein are (like L-NAME effect) endothelial nitric oxide synthase (eNOS)/endothelium-derived nitric oxide-dependent. Inhibition of cyclooxygenase activity with indomethacin (10 microM) or scavenging of superoxide anions with superoxide dismutase (150 units/ml), but not scavenging of hydrogen peroxide with catalase (800 units/ml), enhanced significantly by an essentially similar extent the relaxation to acetylcholine in baicalein-pretreated aortic rings. Relaxant effect to acetylcholine was significantly attenuated in control aortic rings, but was completely abolished in baicalein-pretreated aortic rings in the presence of reduced form of beta-nicotinamide adenine di-nucleotide (beta-NADH, 300 microM). Baicalein blocked beta-NADH (300 microM)-induced transient contractions, suggesting that baicalein may have inhibited activity of NADH/NADPH-oxidase. Baicalein did not alter the failure of acetylcholine to induce relaxation in the presence of pyrogallol (300 microM). In summary, acute exposure to baicalein impairs eNOS/endothelium-derived nitric oxide-mediated vascular tone in rat aortas through the inhibition of endothelium-derived nitric oxide bioavailability coupled to reduced bioactivity of endothelium-derived nitric oxide and to cyclooxygenase-mediated release of superoxide anions.
    Matched MeSH terms: Aorta/drug effects*; Aorta/physiology
  18. Reduction in arterial stiffness with angiotensin II antagonism and converting enzyme inhibition. A comparative study among malay hypertensive subjects with a known genetic profile
    Rehman A, Ismail SB, Naing L, Roshan TM, Abdul Rahman AR
    Am J Hypertens, 2007 Feb;20(2):184-9.
    PMID: 17261465 DOI: 10.1016/j.amjhyper.2006.07.015
    BACKGROUND: Data comparing the effect of losartan and perindopril on aortic stiffness among hypertensive subjects without A(1166)C polymorphism was not available.
    METHODS: The short-term and long-term effects of losartan (50 mg) and perindopril (4 mg) on aortic stiffness measured as carotid femoral pulse wave velocity (PWV) were compared in 39 middle-aged Malay subjects with mild-to-moderate hypertension in a 4-month, double-blind, randomized, controlled, parallel-design study.
    RESULTS: Four-month treatment with both drugs showed a significant reduction in blood pressure (BP) (P < .005) and PWV (P < .05) as compared to the baseline. On the other hand 1-month treatment showed a significant reduction in BP only in perindopril group (P < .05) but not in the losartan group. There was no significant reduction in pulse pressure and PWV after 1 month treatment by both drugs. No significant difference was seen in reduction in BP after 1 month and 4 months treatment between the two drugs. Similarly no significant difference was seen in reduction in PWV between the two drugs after 1 month (P = .613) and 4 months (P = .521) of treatment. Reduction in PWV by losartan (r = 0.470) and perindopril (r = 0.457) correlated significantly only with reduction in DBP (P < .05) and remained significant even after controlling for reduction in DBP (P < .05). Reduction in PWV by both losartan and perindopril was independent of reduction in BP by these drugs.
    CONCLUSIONS: These results showed that long-term treatment with losartan shows similar pressure independent reduction in PWV as perindopril among Malay hypertensive subjects with a homogenous "AA" genotype for angiotensin II type 1 receptor and may serve as a suitable alternative to perindopril.
    Matched MeSH terms: Aorta/drug effects*; Aorta/physiopathology
  19. Mechanisms of the anti-hypertensive effect of Hibiscus sabdariffa L. calyces
    Ajay M, Chai HJ, Mustafa AM, Gilani AH, Mustafa MR
    J Ethnopharmacol, 2007 Feb 12;109(3):388-93.
    PMID: 16973321
    Previous studies have demonstrated the anti-hypertensive effects of Hibiscus sabdariffa L. (HS) in both humans and experimental animals. To explore the mechanisms of the anti-hypertensive effect of the HS, we examined the effects of a crude methanolic extract of the calyces of HS (HSE) on vascular reactivity in isolated aortas from spontaneously hypertensive rats. HSE relaxed, concentration-dependently, KCl (high K(+), 80 mM)- and phenylephrine (PE, 1 microM)-pre-contracted aortic rings, with a greater potency against the alpha(1)-adrenergic receptor agonist. The relaxant effect of HSE was partly dependent on the presence of a functional endothelium as the action was significantly reduced in endothelium-denuded aortic rings. Pretreatment with atropine (1 microM), L-NAME (10 microM) or methylene blue (10 microM), but not indomethacin (10 microM), significantly blocked the relaxant effects of HSE. Endothelium-dependent and -independent relaxations induced by acetylcholine and sodium nitroprusside, respectively, were significantly enhanced in aortic rings pretreated with HSE when compared to those observed in control aortic rings. The present results demonstrated that HSE has a vasodilator effect in the isolated aortic rings of hypertensive rats. These effects are probably mediated through the endothelium-derived nitric oxide-cGMP-relaxant pathway and inhibition of calcium (Ca(2+))-influx into vascular smooth muscle cells. The present data further supports previous in vivo findings and the traditional use of HS as an anti-hypertensive agent.
    Matched MeSH terms: Aorta, Thoracic/drug effects*; Aorta, Thoracic/physiopathology
  20. Des-aspartate angiotensin I (DAA-I) reduces endothelial dysfunction in the aorta of the spontaneously hypertensive rat through inhibition of angiotensin II-induced oxidative stress
    Loh WM, Ling WC, Murugan DD, Lau YS, Achike FI, Vanhoutte PM, et al.
    Vascul. Pharmacol., 2015 Aug;71:151-8.
    PMID: 25869508 DOI: 10.1016/j.vph.2015.03.011
    Des-aspartate angiotensin I (DAA-I), an endogenous nonapeptide, counteracts several effects of angiotensin II on vascular tone. The aim of this study was to investigate the acute protective effect of DAA-I on endothelial function in the spontaneously hypertensive rat (SHR) as well as its effect on angiotensin II-induced contractions and oxidative stress. Aortic rings were incubated with DAA-I (0.1μM) for 30min prior to the assessment of angiotensin II-induced contractions (0.1nM-10μM) in WKY and SHR aortas. Total nitrate and nitrite levels were assessed using a colorimetric method and reactive oxygen species (ROS) were measured by dihydroethidium (DHE) fluorescence and lucigenin-enhanced chemiluminescence. The effect of DAA-I was also assessed against endothelium-dependent and -independent relaxations to acetylcholine and sodium nitroprusside, respectively. Angiotensin II-induced contractions were significantly reduced by DAA-I, losartan and tempol. Incubation with ODQ (soluble guanylyl cyclase inhibitor) and removal of the endothelium prevented the reduction of angiotensin II-induced contractions by DAA-I. Total nitrate and nitrite levels were increased in DAA-I, losartan and tempol treated-SHR tissues while ROS level was reduced by DAA-I and the latter inhibitors. In addition, DAA-I significantly improved the impaired acetylcholine-induced relaxation in SHR aortas whilst sodium nitroprusside-induced endothelium-independent relaxation remained unaffected. The present findings indicate that improvement of endothelial function by DAA-I in the SHR aorta is mediated through endothelium-dependent release of nitric oxide and inhibition of angiotensin II-induced oxidative stress.
    Matched MeSH terms: Aorta, Thoracic/drug effects; Aorta, Thoracic/metabolism
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