Introduction
The gaseous free radical nitric oxide is an abundant intracellular messenger molecule that plays a central role in maintenance of health, and is heavily involved in signal transduction in various cells of the body [1]. This molecule acts as a mediator in the regulation of cardiac function as well as having an important role in regulating contractility of the heart and maintenance of vascular tone in the cardiovascular system. As one of the most significant individuals in our discovery of nitric oxide, Dr. Robert Furchgott pioneered our understanding of this molecule through his experiments on the vasorelaxant properties of acetylcholine and the subsequent proposal of the presence of the endothelium derived relaxing factor, which was later identified to be nitric oxide [7]. Given the observation that cardiovascular disorders are the number one cause of death in many nations around the world, research into the vasorelaxant properties seems particularly relevant in order to help combat rising rates of vascular hypertension and high blood pressure. In this paper, the properties of nitric oxide are discussed largely with respect to the cardiovascular system. This paper focuses on the synthesis and characteristics of nitric oxide, the mechanisms of action by which nitric oxide works and the regulation of nitric oxide in the body, and finally a short summary of Robert Furchgott’s contributions to the discovery of nitric oxide and its properties.
Synthesis of nitric oxide
Nitric oxide is a gaseous, diatomic molecule that plays an important role as a mediator of cardiac function, working largely as a vasodilator in the cardiovascular system. Nitric oxide is synthesized by a family of enzymes known as nitric oxide synthases (...
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...ve stress [8] and can help combat many cardiovascular disorders, thus confirming the protective capabilities of nitric oxide. Another one of nitric oxide’s protective capabilities stems from its role as a potent vasodilator, and these vasodilation properties are primarily achieved through the activity of eNOS. eNOS is a membrane bound protein that is classified as a calcium-calmodulin dependent enzyme [13]. At resting concentrations of calcium, eNOS generates low amounts of nitric oxide, however, as intracellular calcium concentration increases, there is a potent enhancement of nitric oxide production by eNOS [13], which then goes on to cause vasodilation to prevent blockage of blood flow. Due to its generally low output, eNOS is largely associated with basal cardiac function, while iNOS is a much higher output enzyme, generating much more nitric oxide than eNOS [5].
Retrieved on March 2014 from world wide web at http://www.webmd.com/heart-disease/guide/heart-disease-heart-attacks Wolf, Zane Robinson & Hughes, Ronda G (n.d.). Error Reporting and Disclosure. Retrieved on March 2014 from world wide web at http://www.ncbi.nlm.nih.gov/books/NBK2652
Renin angiotensin system activation: Because of decreased blood flow to the kidneys the compensatory mechanisms activate to hold on to sodium and water. When the Blood flow is decreased Angiotensin II is released causing vasoconstriction
Atenolol is a nationally known, commonly used medication that has helped to change the lives of many people in America. Atenolol, also known as Tenormin, is placed in a group of remedies known as beta-blocker. As a Beta-blocker, Atenolol is used to treat a range of bodily disorders in connection with anxiety and tension, such as high blood pressure, angina, irregular heart rhythms, migraines, prevention of a second heart attack, tremors, alcohol withdrawal, anxiety, and glaucoma. The three main malfunctions atenelol is used for are alcohol withdrawal, anxiety disorders, and cardiac disorders.
The cardiovascular system - The cardiovascular system is responsible for transporting nutrients and removing gaseous waste from the body. It consists of the heart, which powers the whole process, the veins, arteries, and capillaries, which deliver oxygen to tissue at the cellular level. The cardiovascular system carries blood that is low in oxygen away from the heart to the lungs via arteries, where oxygen levels are restored through the air once oxygenated, this blood is then carried throughout the body via arteries, keeping our organs and tissue alive. The cardiovascular system is the workhorse of the body, continuously moving to push blood to the cells. If this important system ceases its work, the body dies.
Its ability to inhibit sodium channels within brain cells thereby protecting the cells from hypoxia (lack of oxygen)
...on and forms an inhibitory complex with caveolin-1 leads to decrease in activity of enzyme in the cells. Transcription of Cav-1 gene is regulated by cholesterol responsive elements. Exposure of fibroblast and endothelial cells to free cholesterol and LDL Cholesterol was found to up regulate Cav-1 expression. Ca+2 mobilizing agents cause disinhibiton of e NOS by promoting Ca+2/Calmodulin triggered dissociation of Cav-1.
Coronary heart disease is defined by the hardening of the epicardial coronary arteries. The buildup of plaque in the arteries slowly narrows the coronary artery lumen. In order to better understand the physiology of the disease, it is important to first know the basic anatomy of the human heart. The aorta, located in the superior region of the heart, branches off into two main coronary blood vessels, otherwise known as arteries. The arteries are located on the left and right side of the heart and span its surface. They subsequently branch off into smaller arteries which supply oxygen-rich blood to the entire heart (Texas Heart Institute, 2013). Therefore, the narrowing of these arteries due to plaque buildup significantly impairs blood flow throughout the heart.
Norepinephrine is the neurotransmitter released by sympathetic nerves (e.g., those innervating the heart and blood vessels) and, within the brain, those of the locus coe...
Individuals with AN keep their body in a state of starvation. Their body must function without the sustenance that it needs to continue functioning. Bradycardia is the most common heart arrhythmia for individuals with this disorder. As a result of the caloric deficit, the body tries to decrease cardiac work by reducing cardiac output. (Casiero & Frishman, 2006). The baroreceptor reflex is the body’s mechanism to regulate blood pressure through use of baroreceptors, which then transmits information to the brainstem. The vagal nerve receives this information, then sends impulses to the sinus node to slow the beat of the heart. (Kollai et al, 1994) A study published in the Oxford Heart Journal measured cardiac va...
The heart serves as a powerful function in the human body through two main jobs. It pumps oxygen-rich blood throughout the body and “blood vessels called coronary arteries that carry oxygenated blood straight into the heart muscle” (Katzenstein and Pinã, 2). There are four chambers and valves inside the heart that “help regulate the flow of blood as it travels through the heart’s chambers and out to the lungs and body” (Katzenstein Pinã, 2). Within the heart there is the upper chamber known as the atrium (atria) and the lower chamber known as the ventricles. “The atrium receive blood from the lu...
One source of great mortality and morbidity in Europe and North America is the cardiovascular disease, Atherosclerosis. It is recognized as a chronic inflammatory disease of the intermediate and large arteries characterized by the thickening of the arterial wall and is the primary cause of coronary and cerebrovascular heart disease (Wilson, 2005). It accounts for 4.35 million deaths in Europe and 35% death in the UK each year. Mortality rate are generally higher in men than pre-menopausal woman. Past the menopause, a woman’s risk is similar to a man’s (George and Johnston, 2010). Clinical trials have confirmed that lipid accumulation, endothelial dysfunction, cell proliferation, inflammation matrix alteration and foam cell formation are characteristic features of the earliest pathogenesis of atherosclerotic disease, and that therapies targeted towards the treatment of those conditions are beneficial (Varghese et al 2005). This essay will summarise the development and factors predispose to atherogenesis, and discuss how the comprehension of cell and molecular based mechanism has led to novel therapies for atherosclerosis.
Cardiovascular disease is currently the nation’s leading non-communicable cause of morbidity and mortality. According to the American Heart Association, the most common form of cardiovascular disease is coronary artery disease, a condition in which the heart’s blood supply is reduced due to a narrowing of the coronary arteries. These arteries play a significant role in regulating the flow of oxygenated blood to the heart. As blood circulates through the arteries, it exerts a force against the vessel walls, known as blood pressure. To withstand this pressure, elastic fibers interspersed along the artery walls allow the arteries to expand and recoil. Abnormally high blood pressure, however, will cause these muscles to thicken as a result of tears in the damaged artery walls trapping particles that aggregate as plaque. Progressive build-up of plaque ultimately leads to a narrowing of the arteries, subsequently diminishing blood flow to the heart and other body organs. This cascade of events triggered by high blood pressure illustrates why hypertension is one of the most important risk factors for cardiovascular disease. Affecting 1 in every 3 adults in the United States alone, hypertension substantially raises the risk for heart disease in an affected individual who, most likely, does not show any signs or symptoms. In addition to the risks associated with this “silent killer,” comorbidities such as obesity, diabetes, and high cholesterol can drastically worsen health outcomes in hypertensive patients. Given the high prevalence and severe consequences of hypertension if undetected, researching this particular topic will increase our understanding of the causes of hypertension by identifying and narrowing down lead candidates for pot...
Oxygen is widely used in both chronic and acute cases, in emergency medicine, at hospital or by emergency medical services (Nicholson, 2004 ). Just like any other form of medication oxygen is a drug that if used incorrectly could cause potential harm, even death (Luettel, 2010 ). Oxygen is admitted to the patient with chest pain for two main rationales. The first is by increasing arterial oxygen tension, which in opposing causes a decrease to the acute ischemic injury, and thus over time the entire infarct area (Moradk...
United States. National Center for Biotechnology Information. U.S. National Library of Medicine. High Blood Pressure. Ed. A.D.A.M. Editorial Board. U.S. National Library of Medicine, 23 June 2012. Web. 29 Nov. 2013.
...ional in controlling visceral responses like heartbeat, intestinal contractions and dilation of blood vessels. This can be helpful in treating people with high blood pressure.