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1.
Peptides ; 150: 170733, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-34973286

RESUMO

Aging is the greatest independent risk factor for developing hypertension and cardiovascular-related diseases including systolic hypertension, vascular disease, ischemic events, arrhythmias, and heart failure. Age-related cardiovascular risk is associated with dysfunction of peripheral organ systems, such as the heart and vasculature, as well as an imbalance in the autonomic nervous system characterized by increased sympathetic and decreased parasympathetic neurotransmission. Given the increasing prevalence of aged individuals worldwide, it is critical to better understand mechanisms contributing to impaired cardiovascular autonomic control in this population. In this regard, the renin-angiotensin system has emerged as an important hormonal modulator of cardiovascular function in aging, in part through modulation of autonomic pathways controlling sympathetic and parasympathetic outflow to cardiovascular end organs. This review will summarize the role of the RAS in cardiovascular autonomic control during aging, with a focus on current knowledge of angiotensin II versus angiotensin-(1-7) pathways in both rodent models and humans, pharmacological treatment strategies targeting the renin-angiotensin system, and unanswered questions for future research.


Assuntos
Doenças Cardiovasculares , Sistema Cardiovascular , Hipertensão , Idoso , Envelhecimento , Sistema Nervoso Autônomo/metabolismo , Doenças Cardiovasculares/tratamento farmacológico , Sistema Cardiovascular/metabolismo , Humanos , Hipertensão/metabolismo , Sistema Renina-Angiotensina/fisiologia , Sistema Nervoso Simpático/metabolismo
2.
Auton Neurosci ; 235: 102836, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34246578

RESUMO

The National Institutes of Health hosted a workshop in 2019 to build consensus around the current state of understanding of the pathophysiology of postural orthostatic tachycardia syndrome (POTS) and to identify knowledge gaps that must be addressed to enhance clinical care of POTS patients through research. This second (of two) articles summarizes current knowledge gaps, and outlines the clinical and research priorities for POTS. POTS is a complex, multi-system, chronic disorder of the autonomic nervous system characterized by orthostatic intolerance and orthostatic tachycardia without hypotension. Patients often experience a host of other related disabling symptoms. The functional and economic impacts of this disorder are significant. The pathophysiology remains incompletely understood. Beyond the significant gaps in understanding the disorder itself, there is a paucity of evidence to guide treatment which can contribute to suboptimal care for this patient population. The vast majority of physicians have minimal to no familiarity or training in the assessment and management of POTS. Funding for POTS research remains very low relative to the size of the patient population and impact of the syndrome. In addition to efforts to improve awareness and physician education, an investment in research infrastructure including the development of standardized disease-specific evaluation tools and outcome measures is needed to facilitate effective collaborative research. A national POTS research consortium could facilitate well-controlled multidisciplinary clinical research studies and therapeutic trials. These priorities will require a substantial increase in the number of research investigators and the amount of research funding in this area.


Assuntos
Intolerância Ortostática , Síndrome da Taquicardia Postural Ortostática , Sistema Nervoso Autônomo , Consenso , Humanos , National Institutes of Health (U.S.) , Síndrome da Taquicardia Postural Ortostática/diagnóstico , Síndrome da Taquicardia Postural Ortostática/terapia , Estados Unidos
3.
JFMS Open Rep ; 7(1): 20551169211013295, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34178373

RESUMO

CASE SUMMARY: This case report describes two cats that had subcutaneous ureteral bypass (SUB) systems implanted and subsequently developed duodenal perforations and septic peritonitis associated with the Dacron cuff of the nephrostomy tube. One cat recovered following surgical explantation of the SUB system with intestinal resection and anastomosis of the perforated small intestine, and - at the time of writing - is still alive. The other cat was humanely euthanased intraoperatively at the owner's request owing to its perceived prognosis. RELEVANCE AND NOVEL INFORMATION: To our knowledge this is the first time this complication has been reported following SUB device placement.

4.
Auton Neurosci ; 235: 102828, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34144933

RESUMO

Postural orthostatic tachycardia syndrome (POTS) is a chronic and often disabling disorder characterized by orthostatic intolerance with excessive heart rate increase without hypotension during upright posture. Patients often experience a constellation of other typical symptoms including fatigue, exercise intolerance and gastrointestinal distress. A typical patient with POTS is a female of child-bearing age, who often first displays symptoms in adolescence. The onset of POTS may be precipitated by immunological stressors such as a viral infection. A variety of pathophysiologies are involved in the abnormal postural tachycardia response; however, the pathophysiology of the syndrome is incompletely understood and undoubtedly multifaceted. Clinicians and researchers focused on POTS convened at the National Institutes of Health in July 2019 to discuss the current state of understanding of the pathophysiology of POTS and to identify priorities for POTS research. This article, the first of two articles summarizing the information discussed at this meeting, summarizes the current understanding of this disorder and best practices for clinical care. The evaluation of a patient with suspected POTS should seek to establish the diagnosis, identify co-morbid conditions, and exclude conditions that could cause or mimic the syndrome. Once diagnosed, management typically begins with patient education and non-pharmacologic treatment options. Various medications are often used to address specific symptoms, but there are currently no FDA-approved medications for the treatment of POTS, and evidence for many of the medications used to treat POTS is not robust.


Assuntos
Intolerância Ortostática , Síndrome da Taquicardia Postural Ortostática , Adolescente , Consenso , Feminino , Frequência Cardíaca , Humanos , National Institutes of Health (U.S.) , Síndrome da Taquicardia Postural Ortostática/diagnóstico , Síndrome da Taquicardia Postural Ortostática/terapia , Estados Unidos
5.
J Appl Physiol (1985) ; 130(1): 48-56, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-33211597

RESUMO

One in three Americans suffer from kidney diseases such as chronic kidney disease, and one of the etiologies is suggested to be long-term renal hypoxia. Interestingly, sympathetic nervous system activation evokes a renal vasoconstrictor effect that may limit oxygen delivery to the kidney. In this report, we sought to determine if sympathetic activation evoked by lower body negative pressure (LBNP) would decrease cortical and medullary oxygenation in humans. LBNP was activated in a graded fashion (LBNP; -10, -20, and -30 mmHg), as renal oxygenation was measured (T2*, blood oxygen level dependent, BOLD MRI; n = 8). At a separate time, renal blood flow velocity (RBV) to the kidney was measured (n = 13) as LBNP was instituted. LBNP significantly reduced RBV (P = 0.041) at -30 mmHg of LBNP (Δ-8.17 ± 3.75 cm/s). Moreover, both renal medullary and cortical T2* were reduced with the graded LBNP application (main effect for the level of LBNP P = 0.0008). During recovery, RBV rapidly returned to baseline, whereas medullary T2* remained depressed into the first minute of recovery. In conclusion, sympathetic activation reduces renal blood flow and leads to a significant decrease in oxygenation in the renal cortex and medulla.NEW & NOTEWORTHY In healthy young adults, increased sympathetic activation induced by lower body negative pressure, led to a decrease in renal cortical and medullary oxygenation measured by T2*, a noninvasive magnetic resonance derived index of deoxyhemoglobin levels. In this study, we observed a significant decrease in renal cortical and medullary oxygenation with LBNP as well as an increase in renal vasoconstriction. We speculate that sympathetic renal vasoconstriction led to a significant reduction in tissue oxygenation by limiting oxygen delivery to the renal medulla.


Assuntos
Pressão Negativa da Região Corporal Inferior , Circulação Renal , Humanos , Rim , Sistema Nervoso Simpático , Vasoconstrição , Adulto Jovem
6.
J Parkinsons Dis ; 10(4): 1515-1527, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32986682

RESUMO

BACKGROUND: Current drug treatments have little efficacy in advanced-to-end-stage Parkinson's disease (advPD), yet there are no reports of interventional trials in advPD. D1 dopamine agonists have the potential to provide benefit. OBJECTIVE: To determine the feasibility and safety of the selective D1/D5 dopamine partial agonist PF 06412562 in advPD. METHODS: A two-week, randomized, double blind, crossover phase Ib study in advPD patients compared standard-of-care (SoC) carbidopa/levodopa with PF 06412562. Each week, there was a Day 1 baseline evaluation with overnight levodopa washout, then treatment on Days 2 and 3 with either SoC or PF-06412562 (split dose 25 + 20 mg), followed by discharge on Day 4. Primary endpoints were safety and tolerability. Secondary endpoints were global clinical impression of change (GCI-C) rated by clinicians and caregivers. RESULTS: Eight advPD patients and their caregivers consented to participate and six were randomized (average disease duration: 22 y). None withdrew voluntarily. One participant with baseline Day 1 dehydration, pre-renal kidney injury, and autonomic dysfunction experienced symptomatic and serious hypotension after receiving PF-06412562 in Week 1 and was discontinued from the study. All other adverse events were rated mild (PF-06412562: n = 1, SoC: n = 0), moderate (PF-06412562: n = 1, SoC: n = 1), or severe but non-serious (PF-06412562: n = 3, SoC: n = 2). No clinically meaningful laboratory changes were observed. Among the five participants who completed the study, GCI-C favored PF-06412562 in two per clinicians' and four participants per caregivers' rating. CONCLUSION: PF-06412562 was tolerated in advPD patients. This study provides the feasibility for future safety and efficacy studies in this population with unmet needs.


Assuntos
Carbidopa/farmacologia , Agonistas de Dopamina/farmacologia , Levodopa/farmacologia , Doença de Parkinson/tratamento farmacológico , Receptores de Dopamina D1/agonistas , Idoso , Carbidopa/administração & dosagem , Carbidopa/efeitos adversos , Estudos Cross-Over , Agonistas de Dopamina/administração & dosagem , Agonistas de Dopamina/efeitos adversos , Método Duplo-Cego , Combinação de Medicamentos , Estudos de Viabilidade , Feminino , Humanos , Levodopa/administração & dosagem , Levodopa/efeitos adversos , Masculino , Pessoa de Meia-Idade , Avaliação de Resultados em Cuidados de Saúde , Receptores de Dopamina D5/agonistas , Índice de Gravidade de Doença
7.
Int J Mol Sci ; 21(14)2020 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-32698498

RESUMO

Angiotensin (Ang)-(1-7) is a beneficial renin-angiotensin system (RAS) hormone that elicits protective cardiometabolic effects in young animal models of hypertension, obesity, and metabolic syndrome. The impact of Ang-(1-7) on cardiovascular and metabolic outcomes during aging, however, remains unexplored. This study tested the hypothesis that Ang-(1-7) attenuates age-related elevations in blood pressure and insulin resistance in mice. Young adult (two-month-old) and aged (16-month-old) male C57BL/6J mice received Ang-(1-7) (400 ng/kg/min) or saline for six-weeks via a subcutaneous osmotic mini-pump. Arterial blood pressure and metabolic function indices (body composition, insulin sensitivity, and glucose tolerance) were measured at the end of treatment. Adipose and cardiac tissue masses and cardiac RAS, sympathetic and inflammatory marker gene expression were also measured. We found that chronic Ang-(1-7) treatment decreased systolic and mean blood pressure, with a similar trend for diastolic blood pressure. Ang-(1-7) also improved insulin sensitivity in aged mice to levels in young mice, without effects on glucose tolerance or body composition. The blood pressure-lowering effects of Ang-(1-7) in aged mice were associated with reduced sympathetic outflow to the heart. These findings suggest Ang-(1-7) may provide a novel pharmacological target to improve age-related cardiometabolic risk.


Assuntos
Angiotensina I/farmacologia , Anti-Hipertensivos/farmacologia , Pressão Sanguínea/efeitos dos fármacos , Resistência à Insulina , Fragmentos de Peptídeos/farmacologia , Envelhecimento/efeitos dos fármacos , Angiotensina I/administração & dosagem , Animais , Anti-Hipertensivos/administração & dosagem , Glucose/metabolismo , Hipertensão/tratamento farmacológico , Hipertensão/etiologia , Hipertensão/metabolismo , Insulina/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Fragmentos de Peptídeos/administração & dosagem , Sistema Renina-Angiotensina/efeitos dos fármacos
9.
Auton Neurosci ; 227: 102692, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32526639

RESUMO

Postural tachycardia syndrome (POTS) is a chronic form of orthostatic intolerance associated with cognitive dysfunction. We hypothesized executive function and attention is impaired in POTS during active standing. Eighty-seven POTS participants and 39 healthy controls of similar age, sex, and education level completed executive function (Stroop word-color) and attention (CogState Identification) tests in supine and standing postures in a cross-sectional study. POTS participants had lower executive function (t-score: 48 ± 11 vs. 55 ± 10 control; p = 0.009) and worse attention (reaction speed: 2.78 ± 0.11 vs. 2.69 ± 0.06 control; p < 0.001) during standing. These data provide new evidence that active standing impairs attention and executive functioning in POTS.


Assuntos
Atenção/fisiologia , Disfunção Cognitiva/fisiopatologia , Função Executiva/fisiologia , Síndrome da Taquicardia Postural Ortostática/fisiopatologia , Adolescente , Adulto , Disfunção Cognitiva/etiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Síndrome da Taquicardia Postural Ortostática/complicações , Adulto Jovem
10.
SAGE Open Med ; 8: 2050312120930915, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32587692

RESUMO

OBJECTIVE: Patients diagnosed with peripheral artery disease are difficult to recruit into clinical trials. However, there is currently no high-quality, patient-centered information explaining why peripheral artery disease patients choose to participate or not participate in clinical research studies. METHODS: The current study was a prospective community engagement initiative that specifically asked patients with and without peripheral artery disease: (1) what motivates them to participate in clinical research studies, (2) their willingness to participate in different research procedures, (3) the barriers to participation, (4) preferences about study design, and (5) demographic and disease-related factors influencing participation. Data were gathered through focus groups (n = 19, participants aged 55-79 years) and mailed questionnaires (n = 438, respondents aged 18-85 years). RESULTS: More than half of the respondents stated that they would be willing to participate in a study during evening or weekend time slots. Peripheral artery disease patients (n = 45) were more willing than those without peripheral artery disease (n = 360) to participate in drug infusion studies (48% versus 18%, p < 0.001) and trials of investigational drugs (44% versus 21%, p < 0.001). Motivating factors and barriers to participation were largely consistent with previous studies. CONCLUSION: Adults in our geographic region are interested in participating in clinical research studies related to their health; they would like their doctor to tell them what studies they qualify for and they prefer to receive a one-page advertisement that has color pictures of the research procedures. Peripheral artery disease patients are more willing than those without peripheral artery disease to participate in drug infusion studies, trials of investigational drugs, microneurography, and spinal/epidural infusions.

11.
Vet Surg ; 49(4): 685-693, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32170777

RESUMO

OBJECTIVE: To assess the medium- to long-term radiographically confirmed outcomes in juvenile dogs with hip dysplasia (HD) that did and did not undergo double pelvic osteotomy (DPO). STUDY DESIGN: Retrospective case-controlled. ANIMALS: Twenty-six dogs with HD that were candidates for DPO; 22 dogs underwent DPO (16 bilateral, six unilateral); four dogs did not. METHODS: Initial and follow-up radiographs of DPO candidates (2011-2017) that did and did not undergo surgery were reviewed, and the British Veterinary Association and Kennel Club Hip Dysplasia Scheme score (BVA-HD), osteoarthritis score (OAS) and laxity index score (LI) were determined. Baseline and follow-up BVA-HD, OAS, and change in radiographically confirmed scores were compared by using analysis of variance for correlated samples. RESULTS: There was no significant difference in BVA-HD or OAS between surgically treated and nonsurgically treated cohorts at baseline. Follow-up radiographs (median, 49 months) revealed that most (34/38) hips had a BVA-HD ≤10 after DPO, while four of eight hips from the nonsurgical cohort had BVA-HD >10. Follow-up BVA-HD and OAS were lower in hips after surgery (BVA-HD median 2.15, interquartile range [Q1-Q3] 1.3-4.1; OAS median 1.9, Q1-Q3 1.1-4.1) compared with the nonsurgically treated cohort (BVA-HD median 11.4, Q1-Q3 8.1-17.5, P < .01; OAS median 7.0, Q1-Q3 5.1-13.4, P < .01). Seven hips with an LI >1 had no radiographically confirmed progression of osteoarthritis after DPO. CONCLUSION: Double pelvic osteotomy prevented radiographically confirmed progression of osteoarthritis in the medium- to long-term. Laxity index score > 1 was not a contraindication for DPO in this study. CLINICAL SIGNIFICANCE: Double pelvic osteotomy prevents progression of radiographically confirmed features of osteoarthritis in juvenile dogs with HD.


Assuntos
Doenças do Cão/cirurgia , Luxação do Quadril/veterinária , Osteoartrite/veterinária , Osteotomia/veterinária , Animais , Estudos de Casos e Controles , Progressão da Doença , Cães , Feminino , Luxação do Quadril/cirurgia , Masculino , Osteoartrite/etiologia , Osteotomia/estatística & dados numéricos , Radiografia/veterinária , Estudos Retrospectivos , Resultado do Tratamento
12.
Genes (Basel) ; 11(1)2020 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-31947929

RESUMO

Ehlers-Danlos Syndromes (EDS) are a group of heritable disorders of connective tissue (HDCT) characterized by joint hypermobility, skin hyperextensibility, and tissue fragility. Orthostatic intolerance (OI) is highly prevalent in EDS however mechanisms linking OI to EDS remain poorly understood. We hypothesize that impaired blood pressure (BP) and heart rate control is associated with lower arterial stiffness in people with EDS. Orthostatic vital signs and arterial stiffness were assessed in a cohort of 60 people with EDS (49 female, 36 ± 16 years). Arterial elasticity was assessed by central and peripheral pulse wave velocity (PWV). Central PWV was lower in people with EDS compared to reference values in healthy subjects. In participants with EDS, central PWV was correlated to supine systolic BP (r = 0.387, p = 0.002), supine diastolic BP (r = 0.400, p = 0.002), and seated systolic BP (r = 0.399, p = 0.002). There were no significant correlations between PWV and changes in BP or heart rate with standing (p > 0.05). Between EDS types, there were no differences in supine hemodynamics or PWV measures (p > 0.05). These data demonstrate that increased arterial elasticity is associated with lower BP in people with EDS which may contribute to orthostatic symptoms and potentially provides a quantitative clinical measure for future genotype-phenotype investigations.


Assuntos
Pressão Sanguínea , Síndrome de Ehlers-Danlos/fisiopatologia , Análise de Onda de Pulso , Rigidez Vascular , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Elasticidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
13.
Auton Neurosci ; 224: 102637, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31954224

RESUMO

Despite well-established clinical associations between Hypermobile Ehlers-Danlos syndrome (hEDS) and postural orthostatic tachycardia syndrome (POTS), the precise prevalence is unknown. We therefore evaluated for hEDS in 91 POTS participants using the 2017 hEDS diagnostic checklist, which has three major criteria: 1) generalized joint hypermobility (Beighton score), 2) systemic features, family history, and 3) absence of exclusion criteria. Overall, 28 out of 91 POTS participants (31%) met clinical criteria for hEDS. An additional 24% of participants had generalized joint hypermobility without meeting hEDS criteria. Identifying the prevalence of hEDS in POTS is important for understanding possible mechanisms connecting these two syndromes.


Assuntos
Síndrome de Ehlers-Danlos/epidemiologia , Síndrome da Taquicardia Postural Ortostática/epidemiologia , Adolescente , Adulto , Síndrome de Ehlers-Danlos/complicações , Feminino , Humanos , Instabilidade Articular/complicações , Masculino , Pessoa de Meia-Idade , Síndrome da Taquicardia Postural Ortostática/complicações , Prevalência , Adulto Jovem
15.
Biol Sex Differ ; 10(1): 36, 2019 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-31315689

RESUMO

BACKGROUND: Angiotensin-(1-7) is a beneficial hormone of the renin-angiotensin system known to play a positive role in regulation of blood pressure and glucose homeostasis. Previous studies have shown that in high-fat diet (HFD)-induced obese male mice, circulating angiotensin-(1-7) levels are reduced and chronic restoration of this hormone reverses diet-induced insulin resistance; however, this has yet to be examined in female mice. We hypothesized angiotensin-(1-7) would improve insulin sensitivity and glucose tolerance in obese female mice, to a similar extent as previously observed in male mice. METHODS: Five-week-old male and female C57BL/6J mice (8-12/group) were placed on control diet or HFD (16% or 59% kcal from fat, respectively) for 11 weeks. After 8 weeks of diet, mice were implanted with an osmotic pump for 3-week subcutaneous delivery of angiotensin-(1-7) (400 ng/kg/min) or saline vehicle. During the last week of treatment, body mass and composition were measured and intraperitoneal insulin and glucose tolerance tests were performed to assess insulin sensitivity and glucose tolerance, respectively. Mice were euthanized at the end of the study for blood and tissue collection. RESULTS: HFD increased body mass and adiposity in both sexes. Chronic angiotensin-(1-7) infusion significantly decreased body mass and adiposity and increased lean mass in obese mice of both sexes. While both sexes tended to develop mild hyperglycemia in response to HFD, female mice developed less marked hyperinsulinemia. There was no effect of angiotensin-(1-7) on fasting glucose or insulin levels among diet and sex groups. Male and female mice similarly developed insulin resistance and glucose intolerance in response to HFD feeding. Angiotensin-(1-7) improved insulin sensitivity in both sexes but corrected glucose intolerance only in obese female mice. There were no effects of sex or angiotensin-(1-7) treatment on any of the study outcomes in control diet-fed mice. CONCLUSIONS: This study provides new evidence for sex differences in the impact of chronic angiotensin-(1-7) in obese mice, with females having greater changes in glucose tolerance with treatment. These findings improve understanding of sex differences in renin-angiotensin mechanisms in obesity and illustrate the potential for targeting angiotensin-(1-7) for treatment of this condition.


Assuntos
Angiotensina I/farmacologia , Obesidade/induzido quimicamente , Fragmentos de Peptídeos/farmacologia , Animais , Dieta Hiperlipídica/efeitos adversos , Metabolismo Energético/efeitos dos fármacos , Feminino , Intolerância à Glucose , Resistência à Insulina , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Caracteres Sexuais
16.
Physiol Rep ; 7(2): e13988, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30659773

RESUMO

Emerging evidence suggests that sympathetic vasoconstriction is lower in young women. We hypothesized that increases in muscle sympathetic nerve activity (MSNA) during acute physiological stressors induce less vasoconstriction in young women compared to young men. Healthy young men (n = 10, 27 ± 1 years), young women (n = 12, 25 ± 1 years), and older women (n = 10, 63 ± 6 years) performed the cold pressor test (hand in ice for 2 min) and continuous hypoxia (10% O2 , 90% N2 ) for 5 min. MSNA, femoral blood flow velocity, heart rate, and blood pressure were acquired continuously. Femoral artery diameter was obtained every minute and used to calculate femoral blood flow, and femoral vascular resistance and conductance. MSNA responses to cold pressor test (P = 0.345) and hypoxia (P = 0.969) were not different between groups. Young women had greater femoral blood flow (P = 0.002) and vascular conductance (P = 0.041) responses to cold pressor test compared with young men. The femoral blood flow response to hypoxia was not different between the two sexes but the increase in femoral flow was attenuated in older women compared with younger women (P = 0.036). These data show that young women had paradoxical vasodilation to cold pressor test. The mechanisms responsible for the attenuated sympathetic vasoconstriction or for enhanced vasodilation in young women during the CPT require further investigation.


Assuntos
Artéria Femoral/fisiologia , Hipóxia/fisiopatologia , Estresse Fisiológico/fisiologia , Sistema Nervoso Simpático/fisiologia , Vasodilatação/fisiologia , Adolescente , Adulto , Fatores Etários , Temperatura Baixa , Feminino , Artéria Femoral/inervação , Hemodinâmica , Humanos , Masculino , Pessoa de Meia-Idade , Fatores Sexuais , Vasoconstrição , Adulto Jovem
17.
Clin Auton Res ; 29(2): 231-243, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30413906

RESUMO

Complex and bidirectional interactions between the renin-angiotensin system (RAS) and autonomic nervous system have been well established for cardiovascular regulation under both physiological and pathophysiological conditions. Most research to date has focused on deleterious effects of components of the vasoconstrictor arm of the RAS on cardiovascular autonomic control, such as renin, angiotensin II, and aldosterone. The recent discovery of prorenin and the prorenin receptor have further increased our understanding of RAS interactions in autonomic brain regions. Therapies targeting these RAS components, such as angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers, are commonly used for treatment of hypertension and cardiovascular diseases, with blood pressure-lowering effects attributed in part to sympathetic inhibition and parasympathetic facilitation. In addition, a vasodilatory arm of the RAS has emerged that includes angiotensin-(1-7), ACE2, and alamandine, and promotes beneficial effects on blood pressure in part by reducing sympathetic activity and improving arterial baroreceptor reflex function in animal models. The role of the vasodilatory arm of the RAS in cardiovascular autonomic regulation in clinical populations, however, has yet to be determined. This review will summarize recent developments in autonomic mechanisms involved in the effects of the RAS on cardiovascular regulation, with a focus on newly discovered pathways and therapeutic targets for this hormone system.


Assuntos
Sistema Nervoso Autônomo/fisiologia , Fenômenos Fisiológicos Cardiovasculares , Sistema Renina-Angiotensina/fisiologia , Animais , Sistema Nervoso Autônomo/fisiopatologia , Doenças Cardiovasculares/fisiopatologia , Sistema Cardiovascular/fisiopatologia , Humanos
18.
Am J Physiol Endocrinol Metab ; 315(6): E1204-E1211, 2018 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-30300010

RESUMO

Angiotensin-converting enzyme (ACE) inhibitors reduce body weight, lower blood pressure (BP), and improve insulin sensitivity in animal models of cardiometabolic syndrome. These effects are generally attributed to reduced angiotensin (ANG) II formation; however, these therapies also increase levels of ANG-(1-7), a beneficial hormone opposing ANG II actions. We hypothesized that this ANG-(1-7) generation contributes to the insulin-sensitizing effects of ACE inhibition in obese mice. Adult male C57BL/6J mice were placed on a 60% high-fat diet for 11 wk. During the last 3 wk of diet, mice received normal water or water containing the ACE inhibitor captopril (50 mg/l) as well as the ANG-(1-7) mas receptor antagonist A779 (400 or 800 ng·kg-1·min-1) or saline vehicle via subcutaneous osmotic minipumps. At the end of treatment, arterial BP was measured, and hyperinsulinemic-euglycemic clamps were performed in conscious obese mice receiving vehicle, captopril, captopril plus A779, or A779 ( n = 6-13/group). Captopril reduced body weight (28 ± 2 vs. 41 ± 2 g saline; P = 0.001), lowered systolic BP (109 ± 6 vs. 144 ± 7 mmHg saline; P = 0.041), and improved whole-body insulin sensitivity (steady-state glucose infusion rate: 31 ± 4 vs. 16 ± 2 mg·kg-1·min-1 saline; P = 0.001) in obese mice. A779 attenuated captopril-mediated improvements in insulin sensitivity (23 ± 2 mg·kg-1·min-1; P = 0.042), with no effect on body weight (32 ± 2 g; P = 0.441) or BP (111 ± 7 mmHg; P = 0.788). There was no effect of A779 alone on cardiometabolic outcomes. These data suggest that insulin-sensitizing effects of ACE inhibition are in part due to activation of ANG-(1-7)/ mas receptor pathways and provide new insight into mechanisms underlying the positive metabolic effects of these therapies.


Assuntos
Angiotensina I/metabolismo , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Resistência à Insulina/fisiologia , Obesidade/metabolismo , Fragmentos de Peptídeos/metabolismo , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Receptores Acoplados a Proteínas G/antagonistas & inibidores , Angiotensina II/análogos & derivados , Angiotensina II/farmacologia , Animais , Glicemia/metabolismo , Captopril/farmacologia , Dieta Hiperlipídica , Modelos Animais de Doenças , Insulina/sangue , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fragmentos de Peptídeos/farmacologia , Proto-Oncogene Mas
19.
Auton Neurosci ; 215: 28-36, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-29753556

RESUMO

Postural tachycardia syndrome (POTS) is a disorder characterized by the presence of orthostatic symptoms (including lightheadedness, palpitations, nausea, dyspnea, and tremulousness) as well as excessive upright tachycardia. POTS predominantly affects women of childbearing age. Treating POTS involves a multi-faceted approach using non-pharmacological and pharmacological interventions. There are no pharmacological treatments that are currently United States Food and Drug Administration (FDA) approved for POTS due to lack of randomized controlled trials. Yet, several medications can improve POTS symptoms and are supported by small prospective studies or retrospective case series. Drugs that are most commonly used for POTS target the following mechanisms 1) blood volume expansion, 2) reduction of heart rate, 3) peripheral vasoconstriction and 4) sympatholysis. Pharmacological approaches can also be used to target specific symptoms including "brain fog," fatigue, sleep, and depression. This review outlines pharmacological approaches for treating POTS and summarizes evidence supporting each treatment approach.


Assuntos
Antidiuréticos/uso terapêutico , Fármacos do Sistema Nervoso Autônomo/uso terapêutico , Fármacos Cardiovasculares/uso terapêutico , Eritropoetina/uso terapêutico , Síndrome da Taquicardia Postural Ortostática/tratamento farmacológico , Solução Salina/uso terapêutico , Cloreto de Sódio/uso terapêutico , Antidiuréticos/efeitos adversos , Fármacos do Sistema Nervoso Autônomo/efeitos adversos , Fármacos Cardiovasculares/efeitos adversos , Eritropoetina/efeitos adversos , Humanos , Solução Salina/administração & dosagem , Solução Salina/efeitos adversos , Cloreto de Sódio/efeitos adversos
20.
J Appl Physiol (1985) ; 125(1): 58-63, 2018 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-29648515

RESUMO

Peripheral arterial disease (PAD) is associated with augmented blood pressure (BP) and impaired coronary blood flow responses to exercise, which may increase cardiovascular risk. We investigated the effects of leg revascularization on the BP and coronary blood flow responses to exercise in PAD. Seventeen PAD patients (11 men, 66 ± 2 yr) performed single-leg plantar flexion exercise 24 h before and 1 mo following leg revascularization. BP and heart rate (HR) were measured continuously, and rate pressure product (systolic BP × HR) was calculated as an index of myocardial oxygen demand. Coronary blood velocity was obtained by transthoracic Doppler echocardiography in 8/17 subjects. The mean BP response to plantar flexion exercise was attenuated by leg revascularization (pre-revascularization: 15 ± 4 vs. post-revascularization: 7 ± 3 mmHg, P = 0.025). The HR response to plantar flexion was also attenuated following leg revascularization (pre-revascularization: 9 ± 1 vs. post-revascularization: 6 ± 1 beats/min, P = 0.006). The change in coronary blood velocity with exercise was greater at the post-revascularization visit: 4 ± 1 vs. pre-revascularization: -1 ± 2 cm/s ( P = 0.038), even though the change in rate pressure product was not greater following revascularization in these subjects (pre-revascularization: 2,796 ± 871 vs. post-revascularization: 1,766 ± 378 mmHg·beats/min, P = 0.082). These data suggest that leg revascularization alters reflex control of BP, HR, and coronary blood flow in response to exercise in patients with PAD. NEW & NOTEWORTHY We found that peripheral revascularization procedures lowered exercise blood pressure and improved coronary blood flow in patients with peripheral arterial disease.


Assuntos
Exercício Físico/fisiologia , Hiperemia/fisiopatologia , Doença Arterial Periférica/fisiopatologia , Reflexo/fisiologia , Idoso , Velocidade do Fluxo Sanguíneo/fisiologia , Pressão Sanguínea/fisiologia , Feminino , Coração/fisiopatologia , Frequência Cardíaca/fisiologia , Humanos , Masculino , Músculo Esquelético/fisiologia
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