scholarly journals Activation of hypothalamic AgRP and POMC neurons evokes disparate sympathetic and cardiovascular responses

2020 ◽  
Vol 319 (5) ◽  
pp. H1069-H1077 ◽  
Author(s):  
Jingwei Jiang ◽  
Donald A. Morgan ◽  
Huxing Cui ◽  
Kamal Rahmouni
Keyword(s):  
Blood Pressure ◽  
Arcuate Nucleus ◽  
Cardiovascular Effects ◽  
Cardiovascular Responses ◽  
Melanocortin System ◽  
Physiological Processes ◽  
Essential Components ◽  
Hypothalamic Arcuate Nucleus ◽  
Chronic Activation ◽  
Two Populations

Agouti-related peptide (AgRP)- and proopiomelanocortin (POMC)-expressing neurons of the arcuate nucleus are essential components of the brain melanocortin system that controls various physiological processes. Here, we tested the metabolic and cardiovascular effects of direct activation of these two populations of neurons. Our findings show that, in addition to stimulation of food intake, chemogenetic mediated activation of hypothalamic arcuate nucleus AgRP, but not POMC, neurons reduce renal sympathetic traffic. Despite this, chronic activation of AgRP neurons increased blood pressure. However, chronic activation of POMC neurons led to a significant reduction in blood pressure. Our findings highlight the importance of arcuate nucleus AgRP and POMC neuronal activity in autonomic and cardiovascular regulation.

scholarly journals Tai-chi-chuan and yoga onpostexercise hypotension: comparison to aerobic and resistance exercise

2016 ◽  
Vol 29 (3) ◽  
pp. 543-552
Author(s):  
João Douglas Alves ◽  
Jorge Luiz de Brito Gomes ◽  
Caio Victor Coutinho de Oliveira ◽  
José Victor de Miranda Henriques Alves ◽  
Fabiana Ranielle de Siqueira Nogueira ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Young Women ◽  
Tai Chi ◽  
Cardiovascular Effects ◽  
Cardiovascular Responses ◽  
Tai Chi Chuan ◽  
Post Exercise ◽  
Significant Difference ◽  
Apparently Healthy

Abstract Introduction: Tai-Chi-Chuan and Yoga have becoming popular practices. However is unclear the cardiovascular effects, and if they present similar behavior to aerobic and resistance sessions. Objective: To evaluate the cardiovascular responses during the session and post-exercise hypotension (PEH) of Tai Chi Chuan (TS) and Yoga (YS) in comparison to aerobic (AS) and resistance (SR) exercises. Methods: Fourteen young women (22.3 ± 2 years) apparently healthy performed four sessions (AS, RS, TS and YS). The heart rate (HR), systolic (SBP) and diastolic blood pressure (DBP) were recorded at resting, during (every 10 minutes) and until 50 minutes of recovery. Results: AS, RS, TS e YS showed significant increase in HR compared to resting.AS at 10, 30 e 50 minutes in relation to RS, TS e YS. The RS in relation to TS and YS at 10, 30 and 50 minutes. No significant difference between TS and YS. SBP was significantly increased in AS, RS, TS e YS at 10, 30 e 50 minutes during the session, in relation to rest. AS was significantly higher at 30 e 50 minutes than RS and higher than TS and YS at 10, 30 e 50 minutes. No significant difference in DBP. For PEH, AS, RS and TS significantly reduced at 10, 30 and 50 minutes. YS reduced at 50 minutes. No significant diastolic PEH. Conclusion: TS and YS showed as safe alternatives of exercising in the normotensive young adult woman, despite having lower values, they promote similar hemodynamic behavior to AS and RS.

Influence of apnea on cardiovascular responses to neck suction during exercise

1996 ◽  
Vol 271 (4) ◽  
pp. H1370-H1374 ◽  
Author(s):  
P. Sundblad ◽  
D. Linnarsson
Keyword(s):  
Blood Pressure ◽  
Arterial Pressure ◽  
Isometric Exercise ◽  
Cardiovascular Effects ◽  
Cardiovascular Responses ◽  
Voluntary Contraction ◽  
Dynamic Exercise ◽  
Residual Capacity ◽  
Leg Exercise ◽  
Blood Pressure Responses

Short-lasting neck suction (NS) is a common method to assess the carotid-cardiac baroreflex, and NS is usually applied during apnea to avoid breath-synchronous variations of heart rate (HR) and blood pressure. We hypothesized that the apnea might provoke cardiovascular effects that could confound the HR and blood pressure responses to NS. HR and blood pressure responses to 10-s trains of 50-mmHg pulses of NS were studied in six male subjects during supine rest, upright rest, isometric arm exercise at 30% of maximal voluntary contraction, and dynamic leg exercise at 100 W in the sitting position. Repeated NS sequences were performed during apnea preceded by a relaxed expiration to functional residual capacity and during eupnea. Initial HR responses to NS were similar during eupnea and apnea in all conditions. However, during isometric and dynamic exercise, recordings made under eupneic and apneic conditions differed during the second half of the NS period. During apneic isometric arm contraction, the elevation of mean carotid distending pressure (MCDP) (arterial pressure at carotid level minus NS pressure) was maintained at a 25-35% higher level than during eupneic isometric exercise over the last half of the NS period. In dynamic exercise, mean arterial pressure and MCDP started to increase after 3-5 s of apneic NS, whereas they were maintained during eupnea. One to three seconds later, HR started to drop markedly in apneic subjects, reaching values 20 beats/min lower than those in eupneic subjects at the end of the NS. We conclude that cardiovascular effects of apnea may appear after only 8 s of apnea in dynamic exercise and therefore could confound responses to NS.

scholarly journals The hypothalamic arcuate nucleus: a new site of cardiovascular action of angiotensin-(1–12) and angiotensin II

2011 ◽  
Vol 300 (3) ◽  
pp. H951-H960 ◽  
Author(s):  
Hideki Arakawa ◽  
Vineet C. Chitravanshi ◽  
Hreday N. Sapru
Keyword(s):  
Arcuate Nucleus ◽  
Cardiovascular Responses ◽  
Splanchnic Nerve ◽  
Induced Responses ◽  
Ang Ii ◽  
Vagus Nerves ◽  
Hypothalamic Arcuate Nucleus ◽  
Male Wistar Rats ◽  
Bilateral Vagotomy ◽  
Greater Splanchnic Nerve

The hypothalamic arcuate nucleus (ARCN) has been reported to play a significant role in cardiovascular regulation. It has been hypothesized that the ARCN may be one of the sites of cardiovascular actions of angiotensins (ANGs). Experiments were carried out in urethane-anesthetized, artificially ventilated, adult male Wistar rats. The ARCN was identified by microinjections of N-methyl-d-aspartic acid (NMDA; 10 mM). Microinjections (50 nl) of ANG-(1–12) (1 mM) into the ARCN elicited increases in mean arterial pressure (MAP), heart rate (HR), and greater splanchnic nerve activity (GSNA). The tachycardic responses to ANG-(1–12) were attenuated by bilateral vagotomy. The cardiovascular responses elicited by ANG-(1–12) were attenuated by microinjections of ANG II type 1 receptor (AT1R) antagonists but not ANG type 2 receptor (AT2R) antagonist. Combined inhibition of ANG-converting enzyme (ACE) and chymase in the ARCN abolished ANG-(1–12)-induced responses. Microinjections of ANG II (1 mM) into the ARCN also increased MAP and HR. Inhibition of ARCN by microinjections of muscimol (1 mM) attenuated the pressor and tachycardic responses to intravenously administered ANG-(1–12) and ANG II (300 pmol/kg each). These results indicated that 1) microinjections of ANG-(1–12) into the ARCN elicited increases in MAP, HR, and GSNA; 2) HR responses were mediated via both sympathetic and vagus nerves; 3) AT1Rs, but not AT2Rs, in the ARCN mediated ANG-(1–12)-induced responses; 4) both ACE and chymase were needed to convert ANG-(1–12) to ANG II in the ARCN; and 5) ARCN plays a role in mediating the cardiovascular responses to circulating ANGs.

Cardiovascular effects of cadmium on intravenous and intracerebroventricular administration in rats

1983 ◽  
Vol 61 (11) ◽  
pp. 1430-1432 ◽  
Author(s):  
V. N. Puri ◽  
R. N. Sur
Keyword(s):  
Blood Pressure ◽  
Pressor Response ◽  
Cardiovascular Effects ◽  
Cadmium Acetate ◽  
Cardiovascular Responses ◽  
Cadmium Exposure ◽  
Intracerebroventricular Administration

Cardiovascular responses to the intravenous (i.v.) and the intracerebroventricular (i.c.v.) administration of cadmium acetate were evaluated in rats anaesthetized with urethane. Cadmium acetate (1 mg/kg i.v.) caused an initial fall followed by a persistent rise in blood pressure. Cadmium acetate (1 μg i.c.v.) produced a more marked hypertensive effect. In the spinal-transected rat, the effect of intravenous cadmium was reduced but the effect of intraventricularly administered cadmium was completely abolished. It is, therefore, suggested that both central and peripheral mechanisms are involved in the pressor response to cadmium exposure.

scholarly journals Involvement of the Acyl-CoA binding domain containing 7 in the control of food intake and energy expenditure in mice

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Damien Lanfray ◽  
Alexandre Caron ◽  
Marie-Claude Roy ◽  
Mathieu Laplante ◽  
Fabrice Morin ◽  
...  
Keyword(s):  
Food Intake ◽  
Energy Expenditure ◽  
Arcuate Nucleus ◽  
Binding Domain ◽  
Nucleotide Polymorphism ◽  
Melanocortin System ◽  
Single Nucleotide ◽  
Hypothalamic Arcuate Nucleus ◽  
Paralog Gene ◽  
G Protein Coupled

Acyl-CoA binding domain-containing 7 (Acbd7) is a paralog gene of the diazepam-binding inhibitor/Acyl-CoA binding protein in which single nucleotide polymorphism has recently been associated with obesity in humans. In this report, we provide converging evidence indicating that a splice variant isoform of the Acbd7 mRNA is expressed and translated by some POMC and GABAergic-neurons in the hypothalamic arcuate nucleus (ARC). We have demonstrated that the ARC ACBD7 isoform was produced and processed into a bioactive peptide referred to as nonadecaneuropeptide (NDN) in response to catabolic signals. We have characterized NDN as a potent anorexigenic signal acting through an uncharacterized endozepine G protein-coupled receptor and subsequently via the melanocortin system. Our results suggest that ACBD7-producing neurons participate in the hypothalamic leptin signalling pathway. Taken together, these data suggest that ACBD7-producing neurons are involved in the hypothalamic control exerted on food intake and energy expenditure by the leptin-melanocortin pathway.

scholarly journals Cardiovascular Responses to Repetitive McKenzie Lumbar Spine Exercises

2001 ◽  
Vol 81 (9) ◽  
pp. 1524-1533 ◽  
Author(s):  
Saud Al-Obaidi ◽  
Joseph Anthony ◽  
Elizabeth Dean ◽  
Nadia Al-Shuwai
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Low Back Pain ◽  
Back Pain ◽  
Lumbar Spine ◽  
Cardiovascular Effects ◽  
Cardiovascular Responses ◽  
Low Back ◽  
Pulmonary Risk ◽  
Flexion And Extension

Abstract Background and Purpose. Repetitive exercises of the type recommended by McKenzie for the lumbar spine, such as flexion and extension exercises in standing (FIS and EIS) and lying positions (FIL and EIL), have been used in the management of low back pain for over 20 years. The cardiovascular effects of exercises that involve postural stabilization and the arms and of exercises performed in a lying position are well known. Therefore, the purpose of this study was to examine the cardiovascular effects of 4 exercises used in the McKenzie system. Subjects and Methods. One hundred subjects without cardiovascular or cardiopulmonary disease (mean age=31 years, SD=6.1, range=22–44) and who were representative of people susceptible to low back pain were studied. Subjects were randomly assigned to 1 of 4 exercise groups (ie, FIS, EIS, FIL, and EIL). Subjects performed sets of 10, 15, and 20 repetitions of the assigned exercise, with a 15-minute rest between sets. Heart rate, blood pressure, and rate-pressure product (an index of myocardial work) were recorded before and after each set of repetitions. Results. After 10 repetitions, flexion and extension in lying were more hemodynamically demanding than in standing. This trend persisted for 15 and 20 repetitions; however, at 20 repetitions, the hemodynamic demands were different across exercise groups (ie, FIL>EIL>FIS>EIS). Discussion and Conclusion. Repetitive exercises of the type suggested by McKenzie for the lumbar spine can have cardiovascular effects in people with no cardiovascular or cardiopulmonary conditions. These effects may be important with respect to cardiac work, and patients for whom these exercises are indicated should have a cardiac and pulmonary risk factor assessment to determine whether heart rate and blood pressure should be monitored.

Cardiovascular responses to hypoxia and hypercapnia in barodenervated rats

1990 ◽  
Vol 68 (2) ◽  
pp. 678-686 ◽  
Author(s):  
B. R. Walker ◽  
B. L. Brizzee
Keyword(s):  
Blood Pressure ◽  
Acute Hypoxia ◽  
Peripheral Resistance ◽  
Cardiovascular Effects ◽  
Cardiovascular Responses ◽  
Arterial Baroreflex ◽  
Conscious Rat ◽  
Hypercapnic Hypoxia ◽  
Intact Rats

Experiments were performed to examine the role of the arterial baroreceptors in the cardiovascular responses to acute hypoxia and hypercapnia in conscious rats chronically instrumented to monitor systemic hemodynamics. One group of rats remained intact, whereas a second group was barodenervated. Both groups of rats retained arterial chemoreceptive function as demonstrated by augmented ventilation in response to hypoxia. The cardiovascular effects to varying inspired levels of O2 and CO2 were examined and compared between intact and barodenervated rats. No differences between groups were noted in response to mild hypercapnia (5% CO2); however, the bradycardia and reduction in cardiac output observed in intact rats breathing 10% CO2 were eliminated by barodenervation. In addition, hypocapnic hypoxia caused a marked fall in blood pressure and total peripheral resistance (TPR) in barodenervated rats compared with controls. Similar differences in TPR were observed between the groups in response to isocapnic and hypercapnic hypoxia as well. It is concluded that the arterial baroreflex is an important component of the overall cardiovascular responses to both hypercapnic and hypoxic stimuli in the conscious rat.

scholarly journals Cardiovascular Responses to Hypothalamic Arcuate Nucleus Stimulation in the Rat

Hypertension ◽  
2009 ◽  
Vol 54 (6) ◽  
pp. 1369-1375 ◽  
Author(s):  
Takeshi Nakamura ◽  
Suresh Bhatt ◽  
Hreday N. Sapru
Keyword(s):  
Arcuate Nucleus ◽  
Cardiovascular Responses ◽  
Hypothalamic Arcuate Nucleus
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