Modulation Of Vagal Tone Research Articles

Social Touch: Its Mirror-like Responses and Implications in Neurological and Psychiatric Diseases.

What is the significance of a touch encoded by slow-conducted unmyelinated C-tactile (CT) fibers? It is the so-called affiliative touch, which has a fundamental social impact. In humans, it has been demonstrated that the affiliative valence of this kind of touch is encoded by a dedicated central network, not involved in the encoding of discriminative touch, namely, the "social brain". Moreover, CT-related touch has significant consequences on the human autonomic system, not present in the case of discriminative touch, which does not involve CT fibers as the modulation of vagal tone. In addition, CT-related touch provokes central effects as well. An interesting finding is that CT-related touch can elicit "mirror-like responses" since there is evidence that we would have the same perception of a caress regardless of whether it would be felt or seen and that the same brain areas would be activated. Information from CT afferents in the posterior insular cortex likely provides a basis for encoding observed caresses. We also explored the application of this kind of touch in unphysiological conditions and in premature newborns. In the present literature review, we aim to (1) examine the effects of CT-related touch at autonomic and central levels and (2) highlight CT-related touch and mirror networks, seeking to draw a line of connection between them. Finally, the review aims to give an overview of the involvement of the CT system in some neurologic and psychiatric diseases.

Endogenous cardiotonic steroids and cardiovascular disease, where to next?

Ever since British Physician William Withering first described the use of foxglove extract for treatment of patients with congestive heart failure in 1785, cardiotonic steroids have been used clinically to treat heart failure and more recently atrial fibrillation. Due to their ability to bind and inhibit the ubiquitous transport enzyme sodium potassium pump, thus regulating intracellular Na+ concentration in every living cell, they are also an essential tool for research into the sodium potassium pump structure and function. Exogenous CTS have been clearly demonstrated to affect cardiovascular system through modulation of vagal tone, cardiac contraction (via ionic changes) and altered natriuresis. Reports of a number of endogenous CTS, since the 1980s, have intensified research into their physiologic and pathophysiologic roles and opened up novel therapeutic targets. Substantive evidence pointing to the role of endogenous ouabain and marinobufagenin, the two most prominent CTS, in development of cardiovascular disease has accumulated. Nevertheless, their presence, structure, biosynthesis pathways and even mechanism of action remain unclear or controversial. In this review the current state-of-the-art, the controversies and the remaining questions surrounding the role of endogenous cardiotonic steroids in health and disease are discussed.

PP.02.29

Objective: To report a case of hypertensive patient and describe the cardiovascular adaptations promoted by exercise in cardiac rehabilitation program under pharmacological treatment control after one year of treatment. Design and method: Male, 50, diagnosed with hypertension, asymptomatic from the cardiovascular point of view, in outpatient care. Drug treatment in use: Atenolol 100 mg / day and enalapril 20 mg / day. Physical examination: 80.0 kg; 170 cm; BMI: 27.68 kg / m2; eupneic; stained; hydrated; acyanotic; anicteric; head and neck: no palpable thyroid; members: without edema peripheral perfusion; clean lungs; regular heart rhythm; FC: 70 bpm at rest; BP 150/90 mmHg at rest. Admitted to the cardiac rehabilitation program in May / 2013. The rehabilitation sessions were held three times a week, lasting 30–50 minutes of aerobic exercise. Hemodynamic parameters of heart rate, blood pressure and oxygen saturation (SpO2) were assessed using frequency meter Polar brand, pulse oximeter (Nonin 9500) and BD sphygmomanometer, while the patient was exercising on a treadmill (Biocicle eletromagnetic 2600). Results: The patient had good adherence to the rehabilitation program, attending 100% of the sessions during the entire study period. After 1 year inserted in the cardiac rehabilitation sector, the patient underwent reassessment, which was observed reduction in HR at 13 bpm rest and a reduction in SBP of 40 mmHg, DBP remained the same values. There was also a reduction in medication use: Atenolol from 100 to 50 mg / day and maintained Enalapril 20 mg / day. Conclusions: There were adjustments to tissue metabolic needs with improvements in the redistribution of blood flow in the modulation of vagal tone, the ability to capture and metabolize oxygen, featuring a significant hypotensive effect presented by this case.

Adding the acetylcholinesterase inhibitor, donepezil, to losartan treatment markedly improves long-term survival in rats with chronic heart failure.

Modulation of vagal tone using electrical vagal nerve stimulation or pharmacological acetylcholinesterase inhibition by donepezil exerts beneficial effects in an animal model of chronic heart failure (CHF). Considering different treatment mechanisms underlying renin-angiotensin system (RAS) suppression and parasympathetic activation, we hypothesized that parasympathetic activation together with RAS inhibition could attenuate CHF progression. To test this hypothesis, we investigated the therapeutic effects of a combination of donepezil and losartan in CHF rats with extensive myocardial infarction (MI). Rats (n = 85) that had survived extensive MI were implanted with a blood pressure transmitter and were randomly assigned to receive either a combination of donepezil and losartan (DLT group) or losartan alone (LT group). Compared with the LT group, the DLT group showed a significantly lower heart rate without hypotension. DLT therapy further improved 280-day overall survival relative to the LT group (31% vs. 8%, P = 0.022) by preventing cardiac dysfunction (LV dP/dtmax , 4064 ± 170 vs. 3430 ± 117 mmHg/s, P < 0.01; LV end-diastolic pressure, 17 ± 2 vs. 22 ± 2 mmHg, P < 0.05). DLT therapy was also associated with lower plasma BNP and catecholamine levels, lower cardiac angiotensin II concentrations, and higher capillary density in the peri-infarct region. Combined treatment with donepezil and losartan prevented the progression of cardiac dysfunction and improved the long-term survival of CHF rats with extensive MI, suggesting that this combination could be a novel pharmacotherapy for severe CHF.

Cognitive epidemiology of ethnic health and the CHRM2 vagal vigour hypothesis

AbstractEthnic populations representing areas throughout California were compared regarding cognitive ability, socioeconomic position, and mortality. Cognition and socioeconomic position were inversely correlated with mortality. The single nucleotide polymorphism rs8191992 in the M2 muscarinic receptor gene (CHRM2) was previously linked to IQ and modulation of vagal tone. The CHRM2 vagal vigour hypothesis posits that variation at rs8191992 alters the binding site for a brain-expressed microRNA (hsa-mir-383) thereby changing expression of brain M2 muscarinic receptors to cause pleiotropic effects on cognition and vagus nerve signalling which then affects health via the vagal cholinergic anti-inflammatory pathway. This may help explain ethnic health differences, including the Hispanic Health Paradox, since ethnic differences in rs8191992 allele frequencies correspond to ethnic differences in systemic inflammation and mortality. The rs8191992 A-allele may contribute to the clustering of low IQ and low vagal tone with higher substance abuse, externalizing psychopathology, depression, systemic inflammation, metabolic syndrome, and cardiovascular disease.

Anti-inflammatory properties of omega-3 fatty acids in critical illness: novel mechanisms and an integrative perspective

Fish oil-based nutrition is protective in severe critical care conditions. Regulation of the activity of transcription factor NF-kappaB is an important therapeutic effect of the major omega-3 fatty acids in fish oil, eicosapentaenoic and docosahexaenoic acid (EPA and DHA). Using the articles obtained by a Pubmed research, this article reviews three aspects of NF-kappaB/inflammatory inhibition by fish oil. (1) Inhibition of the NF-kappaB pathway at several subsequent steps: extracellular, free omega-3 inhibits the activation of the Toll-like receptor 4 by endotoxin and free saturated fatty acids. In addition, EPA/DHA blocks the signaling cascade between Toll-like/cytokine receptors and the activator of NF-kappaB, IKK. Oxidized omega-3 also interferes with the initiation of transcription by NF-kappaB. (2) The altered profile of lipid mediators generated during inflammation, with production of the newly identified, DHA-derived inflammation-resolving mediator classes (in addition to the formation of less pro-inflammatory eicosanoids from EPA). Resolvin D1 and Protectin D1 are potent, endogenous, DHA-derived lipid mediators that attenuate neutrophil migration and tissue injury in peritonitis and ischemia-reperfusion injury. Their production is increased in the later stages of an inflammatory response, at which time they enhance the removal of neutrophils. (3) Modulation of vagal tone with potential anti-inflammatory effects: vagal fibers innervating the viscera down-regulate inflammation by activating nicotinic receptors upon infiltrating and resident macrophages. Stimulation of the efferent vagus is therapeutic in experimental septic shock. Fish oil supplementation increases vagal tone following myocardial infarction and in experimental human endotoxinemia. It remains to be shown whether these pleiotropic actions of EPA/DHA contribute to fish oil's therapeutic effect in sepsis.