sympathetic nervous system

Top PDF sympathetic nervous system:

Expression of sympathetic nervous system genes in Lamprey suggests their recruitment for specification of a new vertebrate feature.

Expression of sympathetic nervous system genes in Lamprey suggests their recruitment for specification of a new vertebrate feature.

Classical literature regarding the lamprey sympathetic nervous system is scarce and contradictory. Lampreys possess several neurotransmitters including acetylcholine and noradrenaline in the central nervous system. In addition, sequenced fragments from lamprey DNA reveal the presence of two adrenergic receptors [24] that, in gnathostomes, are the most abundant in the sympathetic nervous system. While this suggests the presence of sympathetic activity in cyclostomes, ganglionic structures are absent in the trunk and tail of the lamprey. Only a sympathetic ganglion formed by small intensely fluorescent cells (SIF cells) has been described adjacent to the adult heart [25,26]. It is possible that such a ganglion would be innervated by the vagus nerve, which is cardio-inhibitory in all vertebrates, with the exception of the cyclostomes [27]. Additionally, it has been suggested that cardiovascular function is controlled by chromaf- fin cells, located on the wall of blood vessels, kidney and urogenital ducts [28].
Mostrar mais

8 Ler mais

Role of sympathetic nervous system and neuropeptides in obesity hypertension

Role of sympathetic nervous system and neuropeptides in obesity hypertension

Recent studies suggest that the MC4-R may be important in mediating leptin’s acute effects on appetite and sympathetic activity. Treatment of rodents with an MC4-R an- tagonist attenuated the acute satiety-induc- ing action of leptin (50) and completely abol- ished the increased renal sympathetic activ- ity associated with acute icv leptin infusion in rats (52). Surprisingly, MC4-R blockade did not prevent leptin-induced stimulation of sympathetic activity in BAT (52). This finding suggests that the thermogenic effects of leptin in BAT are not mediated via the MC4-R, whereas the effect of leptin to en- hance renal sympathetic activity appears to depend on an intact MC4-R. These differing effects of MC4-R blockade on BAT and renal sympathetic activity also suggest that leptin may activate the sympathetic nervous system through multiple central pathways. However, the physiological role of the mel- anocortin system in mediating the effects of leptin on sympathetic activity and arterial pressure, especially in humans, remains to be determined.
Mostrar mais

14 Ler mais

The inhibitory role of sympathetic nervous system in the Ca

The inhibitory role of sympathetic nervous system in the Ca

hypertrophy and prevents the loss of muscle mass in a variety of pathologic conditions in which calpains are activated. This review summarizes evidence indicating that the sympathetic nervous system produces anabolic, protein-sparing effects on skeletal muscle protein metabolism. Studies are reviewed, which indicate that epinephrine secreted by the adrenal medulla and norepinephrine released from adrenergic terminals have inhibitory effects on Ca 2+ -dependent protein degradation, mainly in

8 Ler mais

Effects of renal sympathetic denervation on post-myocardial infarction cardiac remodeling in rats.

Effects of renal sympathetic denervation on post-myocardial infarction cardiac remodeling in rats.

The primary mechanisms of heart failure after AMI include ventricular remodeling and cardiac sympathetic remodeling, chronic over-activation of the sympathetic nervous system, renal sympathetic nerve activation and secondary RAAS activation. [23] Based on previous studies, it was hypothesized that RD could prevent chronic renal afferent and efferent sympathetic activation in heart failure, thus blocking central sympathetic activation and reducing overall activity of the sympathetic nervous system. In addition, the activation of RAAS was also prevented through the inhibition of renin release and blocking the effect of angiotensin II secondary to the activation of RAAS that causes chronic activation of the sympathetic nervous system in the whole body. [24] Thus inhibiting chronic activation of the sympathetic nervous system by blocking local sympathetic nerves such as renal sympathetic nerves, leads to RD having the same effect as sympathetic blockade medications on improving cardiac sympathetic system reconfiguration, reducing myocardial oxygen consumption and ischemic injury, and reducing blood pressure to improve the heart preload and afterload. However, unlike sympathetic blockade medications, RD could avoid a number of adverse reactions such as decreased cardiac contractility. Clinical studies suggest that b- blockers could prolong survival time of heart failure patients with post-MI renal insufficiency. [25] However, patients with severe renal insufficiency will have to avoid using the b-blockers that have to be excreted by the kidneys. [26] This highlights the importance of RD as a new non-drug treatment that blocks the sympathetic nervous system in heart failure.
Mostrar mais

6 Ler mais

Evaluation and Validation of a Method for Determining Platelet Catecholamine in Patients with Obstructive Sleep Apnea and Arterial Hypertension

Evaluation and Validation of a Method for Determining Platelet Catecholamine in Patients with Obstructive Sleep Apnea and Arterial Hypertension

Coy et al., [22] published a meta-analysis and observed similar difficulties due to an absence of standardized criteria for the assessment of monoamines. In addition, some studies have failed to control for confounding factors [22,23]. Only 39% of studies controlled for dietary factors despite their documented influence on sympathetic nervous system (SNS) physiology. Increases in dietary sodium and carbohydrate levels have also been shown to affect catecholamine levels [20]. Obesity and hypertension are associated with high sympathetic tone and are also associated with OSA; both are major confounders when assessing sympathetic activity and catecholamine levels in OSA patients [7,20,23].
Mostrar mais

10 Ler mais

Role of sensory nervous system vasoactive peptides in hypertension

Role of sensory nervous system vasoactive peptides in hypertension

saicin-sensitive C- and Ad-fiber nerves that respond to chemical, thermal, and mechani- cal stimuli (6,7,17,18). These stimuli cause release of CGRP and SP. If the stimulation is powerful enough, it also causes propagation of sensory information back to the central nervous system. Although these nerves have traditionally been thought to “sense” stimuli in the periphery and transmit the information centrally, there was early evidence that they also have an efferent function. It is clear that DRG neuron-derived peptides are released at peripheral sensory nerve terminals in the absence of afferent nerve stimulation (17). The continuous release of peptides from DRG neurons may reflect a paracrine function, with the released peptides binding to nearby receptors. This implies that these neurons participate in the continuous regulation of blood flow and other tissue activities. In- deed, it has been postulated that some DRG neurons are specialized in controlling pe- ripheral effector mechanisms, but have no role in sensation (17). Sensory nerve termi- nals can release CGRP and SP in response to local factors including nerve growth factor (NGF) (19), vascular wall tension (6,7), bradykinin/prostaglandins (20,21), endothe- lin, and the sympathetic nervous system (21). We have demonstrated that these same fac- tors which alter acute release of CGRP can also modulate the long-term production and release of this peptide. Using primary cul- tures of adult rat DRG neurons we have reported that NGF or bradykinin/prostaglan- dins (20,22) can stimulate CGRP synthesis and release, whereas glucocorticoids (22) or a 2 -adrenoreceptor agonists (23) inhibit the stimulatory effects of NGF on CGRP. Thus, alterations in these factors, some of which are known to occur in hypertension, may mediate any changes seen in CGRP or SP synthesis and release.
Mostrar mais

13 Ler mais

Carotid body, insulin, and metabolic diseases: unraveling the links

Carotid body, insulin, and metabolic diseases: unraveling the links

respond by increasing the action potential frequency in their sensory nerve, the carotid sinus nerve (CSN). CSN activity is integrated in the brain stem to induce a panoply of cardiorespiratory reflexes aimed, primarily, to normalize the altered blood gases, via hyperventilation, and to regulate blood pressure and cardiac performance, via sympathetic nervous system (SNS) activation. Besides its role in the cardiorespiratory control the CB has been proposed as a metabolic sensor implicated in the control of energy homeostasis and, more recently, in the regulation of whole body insulin sensitivity. Hypercaloric diets cause CB overactivation in rats, which seems to be at the origin of the development of insulin resistance and hypertension, core features of metabolic syndrome and type 2 diabetes. Consistent with this notion, CB sensory denervation prevents metabolic and hemodynamic alterations in hypercaloric feed animal. Obstructive sleep apnea (OSA) is another chronic disorder characterized by increased CB activity and intimately related with several metabolic and cardiovascular abnormalities. In this manuscript we review in a concise manner the putative pathways linking CB chemoreceptors deregulation with the pathogenesis of insulin resistance and arterial hypertension. Also, the link between chronic intermittent hypoxia (CIH) and insulin resistance is discussed. Then, a final section is devoted to debate strategies to reduce CB activity and its use for prevention and therapeutics of metabolic diseases with an emphasis on new exciting research in the modulation of bioelectronic signals, likely to be central in the future.
Mostrar mais

14 Ler mais

Una comparación de la respuesta autonómica en individuos hipertensos y no hipertensos para una maniobra ortostática

Una comparación de la respuesta autonómica en individuos hipertensos y no hipertensos para una maniobra ortostática

One of the main results of our study was that hypertensive individuals had significant sympathetic elevations after the OM compared to baseline values, which did not occur in non-hypertensive sub- jects. In addition, a significant decrease in parasympathetic activity after the OM was observed in the hypertensive group but not in the non-hypertensive group. Another key finding of this experiment was that elevations of the sympathovagal value compared the baseline value (supine position) (HF/LF ratio) differed significantly (p < 0.05) between the hypertensive and non-hypertensive groups after the OM. The increased activity of the sympathetic nervous system reduces parasympathetic modulation and the HF/LF ratio in hypertensive patients after an OM, which suggests dysfunctional barore- ceptors as the cause of ASH, which occurs even in controlled chronic hypertensive individuals. This result, suggest that at some key times, such as in the morning (Boudreau et al.,2012), OM may poten- tiate the risk factors for ventricular tachycardia, ventricular fibrillation, and sudden cardiac death in patients with coronary heart disease (Carney et al.,2001). Our results contribute to the understanding of this increased cardiovascular vulnerability after waking.
Mostrar mais

10 Ler mais

A randomized, controlled trial to assess short-term black pepper consumption  on 24-hour energy expenditure and substrate utilization

A randomized, controlled trial to assess short-term black pepper consumption on 24-hour energy expenditure and substrate utilization

BP, black pepper; EE, energy expenditure; RQ, respiratory quotient; NPC, no pepper control; RP, red pepper; TRPV1, human vanilloid receptor 1; SNS, sympathetic nervous system; USDA, United States Department of Agriculture; UNC NRI, University of North Carolina Chapel Hill Nutrition Research Institute; GIP, gastric inhibitory polypeptide; GLP-1, glucagon-like peptide 1; PYY, peptide tyrosine tyrosine; PP, pancreatic polypeptide; IRB, Institutional Review Board; TSH, thyroid stimulating hormone; FFM, fat free mass; DXA, dual energy x-ray absorptiometry; RMR, Resting Metabolic Rate; PAL, physical activity level; SMR, sleeping metabolic rate; AEE, activity induced EE; UPLC-QTOFMS, ultra-performance liquid chromatography quadruple time-of-flight mass spectrometry
Mostrar mais

12 Ler mais

ANXIETY DISORDERS INDUCED HYPERTENTION: ISSUE CLINICAL CARE

ANXIETY DISORDERS INDUCED HYPERTENTION: ISSUE CLINICAL CARE

CONCLUSION: Anxiety leads to hypertension because of increased sympathetic nervous system activity and renin-angiotensin-aldosterone system, which ultimately leads to cardiovascular diseases. We must have a look to treat or rule out the anxiety disorders in every patient of hypertension and cardiovascular diseases.

5 Ler mais

Rev. dor  vol.14 número2

Rev. dor vol.14 número2

CASE REPORT: Patient with wrist epidermoid carcinoma, who evolved with phantom limb pain after left forearm amputation. Patient was submitted to conservative treatment and physical re- habilitation, however drug therapy analgesia was insuicient and patient evolved with pain in the amputation stump and sym- pathetic nervous system-mediated pain. Ultimately, patient was submitted to sympathetic venous block followed by diagnostic thoracic sympathetic chain block with signiicant pain decrease. CONCLUSION: Sympathetic nervous system block in this case was induced with venous lidocaine infusion, followed by tho- racic sympathetic chain block as therapeutic option for phan- tom limb pain. his sequence has provided pain relief without adverse efects.
Mostrar mais

4 Ler mais

A randomized controlled study on the effects of bisoprolol and atenolol on sympathetic nervous activity and central aortic pressure in patients with essential hypertension.

A randomized controlled study on the effects of bisoprolol and atenolol on sympathetic nervous activity and central aortic pressure in patients with essential hypertension.

The sympathetic nervous system (SNS) plays a role in the pathophysiology of chronic arterial hypertension by modifying cardiac output and peripheral vascular resistance [1,2]. It is known that sympathetic nerve activity (SNA) can cause changes in blood pressure (BP) through the activation of baroreceptors [3,4]. Although introduced into scientific practice, methods for SNA evaluation are not commonly used in a clinical setting. Analysis of baroreflex sensitivity (BRS) and heart rate (HR) variability (HRV) have been recommended as the diagnostic tools for evaluating

8 Ler mais

ISSN 0100-879X BIOMEDICAL SCIENCES AND CLINICAL INVESTIGATION

ISSN 0100-879X BIOMEDICAL SCIENCES AND CLINICAL INVESTIGATION

on the hypothalamus to increase blood pressure through activation of the sympathetic nervous system (50). Obe- sity is usually associated with selective leptin resistance, a condition characterized by resistance to the feeding and weight reducing effects of leptin, but preservation of the renal sympathoactivation by this hormone (51). Hyperinsulinemia may also play a role in the overactivity of the sympathetic nervous system in obesity. Insulin, like leptin, causes sympathetic activation in different tissues, including the kidney (52). The ability of insulin to stimulate renal sympathetic outflow is preserved in experimental models of obesity, despite the insulin resistance observed in this condition (53). The elevated circulating levels of non-esterified fatty acid (NEFA) from visceral fat depots in obese subjects appear also to mediate the increased sympathetic activity and, ultimately, the raise in blood pres- sure (54). Longitudinal and cross-sectional studies also indicate a role for some newly discovered peptides such as ghrelin (55) and adiponectin (56), as independent risk factors for hypertension in obese patients via modulation of the sympathetic nervous system.
Mostrar mais

10 Ler mais

Arq. Bras. Cardiol.  vol.87 número4

Arq. Bras. Cardiol. vol.87 número4

kidney by increasing renal sodium excretion and nitric oxide production, which may result in a drop in blood pressure. Leptin also increases sympathetic tone in the heart, kidneys, and adrenals, which may raises blood pressure. While short- term infusion of leptin in animals usually does not raise blood pressure, long-term leptin infusion has a pressor effect. Short-term leptin infusions are natriuretic, whereas long-term infusions reduce renal blood flow, thus enhancing sodium retention, and increase renal vascular resistance. Other evidence also implicates leptin in some models of hypertension associated with obesity. Although both insulin and leptin may activate the sympathetic nervous system, regional patterns of sympathetic activation differ with these peptides. Additionally, in humans, the multivariate analysis shows that MSNA seems to be more related to plasma leptin than to insulin 67 .
Mostrar mais

10 Ler mais

Genetic perspectives on the ascidian central nervous system

Genetic perspectives on the ascidian central nervous system

The brain vesicle of ascidian larvae contains two distinct pigmented sensory organs clearly visible through its transparent body. The more anterior pigmented sensory organ, the otolith, is involved in the perception of gravity, whereas the more posterior one, the ocellus, is involved in the perception of light stimuli. The two sensory organs are responsible for the swimming behaviour of the larva (Tsuda et al., 2003). The otolith is composed of a large spherical cell attached to the ventral wall of the sensory vesicle by a narrow stalk. It contains a single pigment granule that occupies most of the cell body. The ocellus is composed of a cup-shaped pigmented cell, a number of photoreceptors and three lens cells (Dilly, 1969; Nicol and Meinertzhagen, 1991). The ascidian ocellus is considered a simple eye. The presence of photoreceptors, of 3 lens cells and of a pigmented cell in the ocellus, suggests some similarity with vertebrate eye. The ascidian “simple eye”, with its close association of the pigment cell and photoreceptors, may thus offer a “unique possibility” to study the developmental programs bringing to both melanization and photoreceptors differentiation. The “unique possibility” is related not only to the simplicity of the system but also to the very well characterized lineages of photoreceptor and pigment cells.
Mostrar mais

11 Ler mais

Central nervous system manifestations of COVID-19 review

Central nervous system manifestations of COVID-19 review

Objective: In this systematic review, we will discuss the evidence on the occurrence of central nervous system (CNS) involvement and neurological manifestations in patients with COVID-19. Methods: MEDLINE (accessed from PubMed) and Scopus from December 01, 2019 to March 26, 2020 were systematically searched for related published articles. In both electronic databases, the following search strategy was implemented and these key words (in the title/abstract) were used: “COVID 19” OR “coronavirus” AND “brain” OR “CNS” OR “neurologic”. Results: Through the search strategy, we could identify two articles about neurological involvement by COVID-19. One of these publications was a narrative review and the other one was a viewpoint. However, the authors scanned the reference lists of the included studies and could identify multiple references. One study, specifically investigated the neurological manifestations of COVID-19 and could document CNS manifestations in 25% of the patients. Most of the studies investigated the manifestations of COVID-19 in general. Conclusion: While neurological manifestations of COVID-19 have not been studied appropriately, it is highly likely that some of these patients, particularly those who suffer from a severe illness, have CNS involvement and neurological manifestations. Precise and targeted documentation of neurological symptoms, detailed clinical, neurological, and electrophysiological investigations of the patients, attempts to isolate SARS-CoV-2 from cerebrospinal fluid, and autopsies of the COVID-19 victims may clarify the role played by this virus in causing neurological manifestations.
Mostrar mais

17 Ler mais

Channelling evolution: canalization and the nervous system.

Channelling evolution: canalization and the nervous system.

Studying canalization in ion channel gene networks may have signifi cant advantages over studying developmental gene networks because it is relatively straightforward to measure the amounts of ion channels expressed in single identifi ed neurons, to alter the expression of individual ion channels, and to relate these alterations to behaviour. I am currently pursuing the impact of ion channel compensation in Drosophila photoreceptors (Niven et al. 2003a, 2003b, 2003c). In this system, changes in ion channel expression produce changes in the coding of visual information, which may lead to behavioural differences. The possible role of ion channel compensation in canalizing the evolution of the
Mostrar mais

3 Ler mais

J. Pediatr. (Rio J.)  vol.88 número1 en a04v88n01

J. Pediatr. (Rio J.) vol.88 número1 en a04v88n01

Summary of the indings: Prevalence of diabetes mellitus has been increasing over the years in many countries. The complications caused by this disease in the digestive system, such as gastrointestinal symptoms (nausea, vomiting, abdominal pain, heartburn, dysphagia, constipation, diarrhea, and fecal incontinence) are well known. The pathogenesis of changes in the gastrointestinal functions in patients with diabetes mellitus is still being investigated at the same time as the role of the enteric nervous system and its neurotransmitters has gained signiicance. As a consequence of the complications in the digestive system, which damage the enteric nervous system, patients with diabetes mellitus may have speciic gastrointestinal motility disorders, some of which may be of great relevance, such as diabetic gastroparesis, constipation, and diarrhea. Gastrointestinal dysfunction increases the morbidity of diabetes mellitus and worsens the quality of life of diabetic individuals.
Mostrar mais

8 Ler mais

Human Immunodeficiency Virus and the Central Nervous System

Human Immunodeficiency Virus and the Central Nervous System

The neurological manifestations directly related to HIV are acute viral meningitis, chronic meningitis, HIV-associated dementia (HAD), vacuolar myelopathy, and involvement of the periphe[r]

10 Ler mais

Dengue in patients with central nervous system , Brazil

Dengue in patients with central nervous system , Brazil

D engue is the most prevalent arboviral infection in humans (1). Since the reintroduction of dengue virus (DENV) into Brazil in the 1980s, >60% of the reported dengue cases in this region of the Western Hemisphere have occurred there (2). As the disease has become more common, unusual clinical signs, some of which involve the central nervous system, have been observed in dengue patients (2–4). We therefore assessed prevalence of dengue neurologic cases from Ceará State, Brazil, a region where dengue is endemic.

3 Ler mais

Show all 10000 documents...