Cardiovascular diseases sympathetic nervous system

The role of the sympathetic nervous system in renal injury, end-stage renal disease, and renovascular hypertension are discussed through a literature review accompanying sympathetic nerve mechanisms in hypertension and obesity. Relevant studies of sympathetic nerve activity and 32-adrenoceptor polymorphism might contribute to the onset and maintenance of renal injury in healthy subjects and in patients with chronic heart failure and cardiovascular events in ESRD patients. A better understanding of the relationships of sympathetic nerve activity with renal injury might help clinical implications (treatment) for renal injury in hypertensive patients and hypertension in patients with ESRD. Recently, the role of denervation of renal sympathetic nerve in refractory hypertension has been examined and showed its efficacy in humans. The outcome from the study have not been established, but a number of animal studies show theoretical benefits for those patients in the acute phase. Further studies are needed to clarify the relationships between the sympathetic nerve activity and renal injury. 

Medical pain morphine is the drug of choice for the relief of pain due to myocardial infarction. Relief of ischemic pain decreases sympathetic nervous system activity thus reducing myocardial oxygen demand. Morphine is used in patients with acute pulmonary edema for its cardiovascular effects and to decrease air hunger. Morphine can be used to treat the pain of sickle cell disease with crisis. Morphine can be used to treat the pain of Guillain-Barre syndrome, osteoarthritis and obstetric pain. Morphine s sedative effects can be utilized in the intubated and ventilated patient. 

The adrenergic system is an essential regulator that increases cardiovascular and metabolic capacity during situations ofstress, exercise, and disease. Nerve cells in the central and peripheral nervous system synthesize and secrete the neurotransmitters noradrenaline and adrenaline. In the peripheral nervous system, noradrenaline and adrenaline are released from two different sites noradrenaline is the principal neurotransmitter of sympathetic neurons that innervate many organs and tissues. In contrast, adrenaline, and to a lesser degree noradrenaline, is produced and secreted from the adrenal gland into the circulation (Fig. 1). Thus, the actions of noradrenaline are mostly restricted to the sites of release from sympathetic nerves, whereas adrenaline acts as a hormone to stimulate many different cells via the blood stream. 

Heart rate (HR), heart rate variability and blood pressure are regulated, in part, by the sympathetic and parasympathetic nervous systems. Changes in one or more may inerease the risk of cardiovascular events (e.g. arrhythmias, myocardial infarction). Decreases in heart rate variability have been associated with cardiovaseular mortality/morbidity in older adults and those with significant heart disease. Eine particles in ambient concentrations have recently been implicated in deereases of heart rate variability (Timonen et al. 2006), increased risk of arrhythmias (Metzger et al. 2004 Lanki et al. 2006) and increased blood pressure (Timonen et al. 2006) in particular in older subject with compromised health. Additionally inhaled particles seem to enhance blood coagulation (Riickerl et al. 2007a, b). 

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