ascorbic-acid and Carotid-Stenosis

Some observational and randomized, clinical interventional studies have indicated that the antioxidative vitamins C (ascorbic acid) and E (alpha-tocopherol) can reduce intima-media thickness of the carotid arteries. It is, however, not clarified whether these vitamins may have a preventive effect against cardiovascular events.. The literature on the effects in relation to several cardiovascular endpoints of vitamins C and E, also used in combination, has been evaluated. The literature has been continuously and systematically collected over many years and supplemented by recent studies retrieved from Medline.. Observational studies including mainly healthy individuals have shown a favourable relationship between intake of vitamins C and E, also taken in combination, and subsequent cardiovascular events. However, most randomized, clinical interventional studies including patients with manifest atherosclerotic disease have not been able to document such a relationship.. The discrepancy found between observational studies and clinical interventional studies may be due to different study populations (healthy/ill individuals) and differences regarding age, sex, diet, smoking, degree of oxidative stress and other probable confounding factors. The significance of vitamins C and E in preventing cardiovascular disease is in our opinion not yet clarified.

Topics: Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Carotid Stenosis; Humans; Vitamin E

The clinical manifestations of arteriosclerosis (cardiovascular, stroke and peripheral artery diseases) represent the leading causes of morbidity and mortality in industrialized countries. The early in vivo diagnosis and follow up of subclinical progression of arteriosclerosis is important for the evaluation of efficient preventive and therapeutic interventions. The carotid artery intima-media thickness (IMT) is a reliable surrogate marker of the arteriosclerosis and could be easily investigated with high resolution B-mode sonography. Due to its good reproducibility, the IMT measurement is optimal for tracking the progression or regression of atherosclerotic disease. The increase of IMT is influenced by numerous vascular risk factors (age, smoking, hypertension, dyslipidemia, alcohol etc.) and positively associated with the incidence of vascular events in the arterial vasculature (stroke, myocardial infarct). Studies with lipid-lowering, antihypertensive, antidiabetic drugs, hormones confirmed, that modifying of vascular risk factors significantly reduces the progression of IMT. It is probable, that reduced progression of IMT is also accompanied with the decrease of future vascular events.

Topics: Antihypertensive Agents; Ascorbic Acid; Cardiovascular Agents; Carotid Arteries; Carotid Stenosis; Disease Progression; Estradiol; Humans; Hypolipidemic Agents; Risk Factors; Tunica Intima; Tunica Media; Ultrasonography; Vitamin E

Mitochondrial encephalopathy, lactic acidosis and stroke-like episodes (MELAS) are thought to be rarely accompanied by macroangiopathy. We reported a case of MELAS that presented right distal internal carotid arterial (ICA) stenosis and reviewed 12 similar previously reported cases involving intracranial large blood vessels.. A 38-year-old man suffered from recurrent stroke-like episodes (SE) such as alternating hemiparesis (right lesion 3 years ago and current left lesion), cortical blindness and seizure for 3 years, and was previously misdiagnosed as cerebral infarction. Magnetic Resonance Angiography (MRA) and Digital Subtraction Angiography (DSA) revealed right distal ICA stenosis and sparse cortex blood vessels, which were related to the previous SE.. He was diagnosed by genetic screening (a mitochondrial DNA A3243G point mutation) and presence of high lactic acidosis (4.03 mmol/L), which rose to 7.8 mmol/L after exercise.. The patient received Coenzyme Q10, vitamin C, L-arginine for 2 weeks and valproic acid sodium (400 mg bid) to prevent seizures till now.. He is currently less active and intelligent than his peers, with occasional seizures, and needs family care.. Till date, there are 12 reported cases of MELAS combined with major cerebral arteries abnormalities including stenosis, dissection, occlusion, reversible vasoconstriction, aneurysms, and atherosclerosis. Hence, macroangiopathy in MELAS is not very rare. There is correlation between the affected vessels and the lesions in some cases, but not in others, which may increase the misdiagnosis rate. Hence, mitochondrial diseases cannot be excluded due to concurrent macroangiopathic lesions.

Topics: Acidosis, Lactic; Adult; Arginine; Ascorbic Acid; Carotid Stenosis; Humans; Male; MELAS Syndrome; Mitochondrial Encephalomyopathies; Point Mutation; Ubiquinone; Valproic Acid

The notion that oxidation of lipids and propagation of free radicals may contribute to the pathogenesis of atherosclerosis is supported by a large body of evidence. To circumvent the damage caused by oxygen free radicals, antioxidants are needed which provide the much needed neutralization of free radical by allowing the pairing of electrons. In this study we have investigated the effect of ascorbic acid, a water soluble antioxidant on the development of hypercholesterolemia induced atherosclerosis in rabbits. Rabbits were made hypercholesterolemic and atherosclerotic by feeding 100 mg cholesterol/day. Different doses of ascorbic acid were administered to these rabbits. Low dose of ascorbic acid (0.5 mg/100 g body weight/day) did not have any significant effect on the percent of total area covered by atherosclerotic plaque. However, ascorbic acid when fed at a higher dose (15 mg/100 g body weight/day) was highly effective in reducing the atherogenecity. With this dose the percent of total surface area covered by atherosclerotic plaque was significantly less (p < 0.001). This suggests that use of ascorbic acid may have great promise in the prevention of hypercholesterolemia induced atherosclerosis.

Topics: Animals; Antioxidants; Aorta; Ascorbic Acid; Carotid Stenosis; Cholesterol; Cholesterol, HDL; Cholesterol, LDL; Coronary Artery Disease; Diet, Atherogenic; Hypercholesterolemia; Lipid Peroxidation; Malondialdehyde; Rabbits

The oxidative modification of LDL is thought to play a crucial role in the initiation of atherosclerosis. Antioxidant vitamins can protect LDL from oxidation, and high intakes or blood concentrations of these vitamins have been linked with a reduced risk of cardiovascular disease. Few data are available on the importance of antioxidant vitamins in earlier stages of atherogenesis.. We investigated the cross-sectional relation between antioxidant vitamin status and carotid atherosclerosis in a group of elderly persons.. The study sample comprised 468 men and women aged 66-75 y living in Sheffield, United Kingdom. Duplex ultrasonography was used to measure intima-media thickness and the degree of stenosis in the extracranial carotid arteries. Antioxidant vitamin status was assessed by measuring fasting plasma concentrations of vitamin C, vitamin E, and beta-carotene.. In the men, after adjustment for age and cardiovascular disease risk factors, a 20% higher plasma vitamin C concentration was associated with a 0.004-mm smaller intima-media thickness; a 20% higher beta-carotene concentration was associated with a 0.005-mm smaller intima-media thickness. Compared with men with high blood concentrations of beta-carotene or cholesterol-adjusted vitamin E, those with low blood concentrations of these vitamins were 2.5 times as likely to have carotid stenosis of >30%. We found no significant trends between plasma concentrations of antioxidant vitamins and either measure of carotid atherosclerosis in the women.. A high antioxidant vitamin status may help to prevent the initiation and progression of early atherosclerotic lesions in men.

Topics: Aged; Aging; Antioxidants; Ascorbic Acid; beta Carotene; Carotid Artery Diseases; Carotid Stenosis; Cross-Sectional Studies; Female; Humans; Male; Nutritional Status; Tunica Media; Vitamin E; Vitamins

It has been reported that systemic and local redox state may have an important role in the functional and organic changes characterizing the process of vascular response to injury. Carotid endarterectomy to remove atherosclerotic plaque is followed by a long lasting healing and remodeling process that can be carefully followed over time with noninvasive ultrasonography. Plasma vitamin C concentration and native LDL (n-LDL) content in lipid peroxides, vitamin E, beta-carotene, and lycopene as well as LDL susceptibility to peroxidation were assessed in 45 patients undergoing elective endarterectomy for internal carotid stenosis, at baseline, 24 hours, 3 and 15 days, and 1 month after surgery. Serial duplex scans were performed in all patients postoperatively and 3, 6, and 12 months. The changes in far wall thickness (FW) and % renarrowing from postoperatively to 12 months were used as remodeling indices. Plasma antioxidant vitamins and lag-phase showed a sharp and significant decrease during the first 24-hours after surgery remaining unchanged until the third day, whereas, an opposite trend was evidenced for n-LDL content in lipid peroxides and serum ceruloplasmin. After the third day all the parameters returned progressively to baseline within one month from endarterectomy. Interestingly, the n-LDL lipid peroxide content, the serum ceruloplasmin and the plasma vitamin C concentration, measured at 24 and 3 days from surgery, were significantly associated to the change in % renarrowing from postoperatively to 12 months. The higher the LDL content in lipid peroxides, the higher the serum level of ceruloplasmin, the lower the plasma content in vitamin C and the higher the % of vessel renarrowing. In conclusion, carotid endarterectomy with atherosclerotic plaque removal is associated with an acute and prolonged increase in systemic oxidative stress that influences vascular healing and late luminal loss.

Topics: Aged; Ascorbic Acid; beta Carotene; Carotenoids; Carotid Artery, Internal; Carotid Stenosis; Ceruloplasmin; Cholesterol, LDL; Elective Surgical Procedures; Endarterectomy, Carotid; Female; Follow-Up Studies; Humans; Lycopene; Male; Middle Aged; Multivariate Analysis; Oxidative Stress; Postoperative Complications; Thiobarbituric Acid Reactive Substances; Time Factors; Ultrasonography; Vitamin E; Wound Healing

In this experimental study is illustrated an original model of cerebral asymmetric ischemia and reperfusion in the rat, induced by unilaterally elevating ICP and clamping the corresponding common carotid artery, that allows a direct comparison of the two brain hemispheres, one normal and the other ischemic, of the same animal.. The experimental procedure consisted in grafting two screws through the skull on the right side of the sagittal suture, one of them being connected to a Queckenstedt manometer for monitoring ICP variations. A nitroprusside solution (1 mg/ml administered through the femoral vein at a flow rate of 0.103 ml/min) was infused to achieve a significant drop of MABP. At this time point, animals were subjected to 5 min of ischemia and 10 min of reperfusion induced by clamping and declamping the right common carotid artery. During the whole period of ischemia and reperfusion ICP and MABP were constantly monitored. In order to provide an outlook on the metabolic alterations of brain tissue occurring during ischemia and reperfusion phenomena, several biochemical parameters of cellular energy metabolism and of oxygen radical-induced membrane damage were determined by a sensitive and reproducible HPLC method on perchloric acid tissue extracts.. The validity of the present model was supported by the finding of significant intrahemispheric differences in the concentration of several compounds considered as biochemical markers of tissue injury, such as adenosine 5'-triphosphate catabolites and malondialdehyde, this last indicating the damaging action of oxygen free radicals on cell membrane phospholipids.

Topics: Animals; Ascorbic Acid; Blood Pressure; Brain Ischemia; Carotid Stenosis; Chromatography, High Pressure Liquid; Disease Models, Animal; Intracranial Pressure; Lipid Peroxidation; Male; Malondialdehyde; Neurons; Rats; Rats, Wistar; Reperfusion Injury; Reproducibility of Results; Sensitivity and Specificity