keyword
MENU ▼
Read by QxMD icon Read
search

Chemoreflex

keyword
https://www.readbyqxmd.com/read/28215596/sex-specific-respiratory-effects-of-acute-and-chronic-caffeine-administration-in-newborn-rats
#1
REVIEW
Hayet Kouchi, NagaPraveena Uppari, Vincent Joseph, Aida Bairam
Caffeine is widely used for the treatment of apnea of prematurity (AoP) but whether this effect varies with sex is unknown. To shed some light on this question, we present a summary of data obtained on the effects of caffeine on the respiratory chemoreflexes and apnea frequency in 1- and 12-days old male and female rats. Caffeine was either administered as a single acute injection (10mg/kg, i.p.) or for 10 consecutive days (7.5mg/kg/day between 3-12days of life by gavage, simulating its clinical use). Acute caffeine had little effects on breathing in 1-day old male and female rats...
February 16, 2017: Respiratory Physiology & Neurobiology
https://www.readbyqxmd.com/read/28188852/the-k%C3%A3-lliker-fuse-nucleus-acts-as-a-timekeeper-for-late-expiratory-abdominal-activity
#2
Sarah E M Jenkin, William K Milsom, Daniel B Zoccal
While the transition from the inspiratory to the post-inspiratory (post-I) phase is dependent on the pons, little attention has been paid to understanding the role of the pontine respiratory nuclei, specifically the Kölliker-Fuse nucleus (KF), in transitioning from post-I to the late expiratory (late-E) activity seen with elevated respiratory drive. To elucidate this, we used the in situ working heart-brainstem preparation of juvenile male Holtzman rats and recorded from the vagus (cVN), phrenic (PN) and abdominal nerves (AbN) during baseline conditions and during chemoreflex activation [with potassium cyanide (KCN; n=13) or hypercapnia (8% CO2; n=10)] to recruit active expiration...
February 8, 2017: Neuroscience
https://www.readbyqxmd.com/read/28181258/cardiac-diastolic-and-autonomic-dysfunction-are-aggravated-by-central-chemoreflex-activation-in-hfpef-rats
#3
Camilo Toledo, David C Andrade, Claudia Lucero, Alexis Arce-Alvarez, Hugo S Díaz, Valentín Aliaga, Harold D Schultz, Noah J Marcus, Mónica Manríquez, Marcelo Faúndez, Rodrigo Del Rio
Heart failure (HF) patients with preserved ejection fraction (HFpEF) display irregular breathing, sympatho-vagal imbalance, arrhythmias, and diastolic dysfunction. It has been shown that tonic activation of central and peripheral chemoreflex pathway plays a pivotal role in the pathophysiology of HF with reduced ejection fraction. In contrast, no studies to date have addressed chemoreflex function or its effect on cardiac function in HFpEF. Therefore, we tested whether peripheral and central chemoreflexes are hyperactive in HFpEF and if chemoreflex activation exacerbates cardiac dysfunction and autonomic imbalance...
February 8, 2017: Journal of Physiology
https://www.readbyqxmd.com/read/28177673/interleukin-1beta-suppresses-the-ventilatory-hypoxic-response-in-rats-via-prostaglandin-dependent-pathways
#4
Nina Pavlovna Aleksandrova, Galina Anatol'yevna Danilova, Vjacheslav Georgievich Aleksandrov
We investigated the effect of the major inflammatory cytokine interleukin-1beta (IL-1β) on the ventilatory response to hypoxia. The goal was to test the hypothesis that IL-1β impairs the hypoxic ventilatory response in vivo by indirectly inhibiting respiratory neurons in the brainstem via prostaglandins. Thus, IL-1β was delivered by cerebroventricular injection, and the ventilatory hypoxic response was assessed in anesthetized, spontaneously breathing rats pretreated with or without diclofenac, a nonspecific inhibitor of prostaglandin synthesis...
January 22, 2017: Canadian Journal of Physiology and Pharmacology
https://www.readbyqxmd.com/read/28132741/respiratory-muscle-training-improves-chemoreflex-response-heart-rate-variability-and-respiratory-mechanics-in-rats-with-heart-failure
#5
Rodrigo B Jaenisch, Edson Quagliotto, Chalyne Chechi, Leonardo Calegari, Fernando Dos Santos, Audrey Borghi-Silva, Pedro Dal Lago
BACKGROUND: The aim of the present report was to evaluate respiratory muscle training (RMT) effects on hemodynamic function, chemoreflex response, heart rate variability, and respiratory mechanics in rats with heart failure (HF rats). METHODS: Wistar rats were divided into 4 groups: sedentary-sham (Sed-Sham, n = 8), respiratory muscle trained-sham (RMT-Sham, n = 8), sedentary-HF (Sed-HF, n = 8) and respiratory muscle trained-HF (RMT-HF, n = 8). Animals were submitted to an RMT protocol performed 30 minutes per day, 5 days per week for 6 weeks, whereas the sedentary animals did not exercise...
November 11, 2016: Canadian Journal of Cardiology
https://www.readbyqxmd.com/read/28106557/blunted-respiratory-responses-in%C3%A2-the%C3%A2-streptozotocin-induced-alzheimer-s-disease-rat-model
#6
Dalton L Ebel, Christopher G Torkilsen, Tim D Ostrowski
Alzheimer's disease (AD) is known for the progressive decline of cognition and memory. In addition to these disease-defining symptoms, impairment of respiratory function is frequently observed and often expressed by sleep-disordered breathing or reduced ability to adjust respiration when oxygen demand is elevated. The mechanisms for this are widely unknown. Postmortem analysis from the brainstem of AD patients reveals pathological alterations, including in nuclei responsible for respiratory control. In this study, we analyzed respiratory responses and morphological changes in brainstem nuclei following intracerebroventricular (ICV) injections of streptozotocin (STZ), a rat model commonly used to mimic sporadic AD...
January 20, 2017: Journal of Alzheimer's Disease: JAD
https://www.readbyqxmd.com/read/28073937/activity-of-tachykinin1-expressing-pet1-raphe-neurons-modulates-the-drive-to-breathe
#7
Morgan L Hennessy, Andrea Corcoran, Rachael D Brust, Eugene E Nattie, Susan Dymecki
: Homeostatic control of breathing, heart rate, and body temperature relies on circuits within the brainstem modulated by the neurotransmitter serotonin (5-HT). Mounting evidence points to specialized neuronal subtypes within the 5-HT system, which have borne out in functional studies, including the modulation of distinct facets of homeostatic control. These functional differences, read out at the organismal level, are likely subserved by differences among 5-HT neuron subtypes at the cellular and molecular levels, including differences in the capacity to co-express other neurotransmitters such as glutamate, GABA, thyrotropin releasing hormone, and substance P encoded by the Tachykinin-1 (Tac1) gene...
January 10, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/28070480/central-congenital-hypoventilation-syndrome-associated-with-hypoglycemia-and-seizure
#8
Emily Hopkins, James Stark, Ricardo A Mosquera
Central Congenital Hypoventilation Syndrome (CCHS) is a rare diagnosis that presents with various forms of autonomic dysfunction. The disease is characterized by reduced chemoreflexes and severe hypoventilation during sleep. Several case reports have noted that patients with CCHS have been found to suffer from hypoglycemic episodes, which frequently present as a seizure. In this report, we will review previous case presentations to alert the physicians about this association with hypoglycemic episodes. Early treatment and monitoring of hypoglycemia will prevent further complications for these populations...
2017: Respiratory Medicine Case Reports
https://www.readbyqxmd.com/read/28065687/restless-legs-syndrome-and-cardiovascular-disease-a-research-roadmap
#9
REVIEW
Daniel J Gottlieb, Virend K Somers, Naresh M Punjabi, John W Winkelman
In this paper, we first critically appraise the epidemiologic literature examining the association of restless legs syndrome (RLS) with cardiovascular disease (CVD) and then consider whether lessons learned from the study of cardiovascular consequences of other sleep disorders might inform a research agenda to examine the potential mechanisms of cardiovascular morbidity of RLS. Cross-sectional and longitudinal studies are both mixed as to whether there is a meaningful association of RLS and CVD. On the other hand, numerous cross-sectional and longitudinal observational studies have shown a strong association of obstructive sleep apnea (OSA) with CVD risk...
October 27, 2016: Sleep Medicine
https://www.readbyqxmd.com/read/28062485/activation-of-bitter-taste-receptors-in-pulmonary-nociceptors-sensitizes-trpv1-channels-through-plc-and-pkc-signaling-pathway
#10
Qihai Gu, Deanna S Joe, Carolyn A Gilbert
Bitter taste receptors (T2Rs), a G-protein-coupled receptor family capable of detecting numerous bitter-tasting compounds, have recently been shown to be expressed and play diverse roles in many extraoral tissues. Here we report the functional expression of T2Rs in rat pulmonary sensory neurons. In anesthetized spontaneously breathing rats, intratracheal instillation of T2Rs agonist chloroquine (10 mM, 0.1 ml) significantly augmented chemoreflexes evoked by right-atrial injection of capsaicin, a specific activator for transient receptor potential vanilloid receptor 1 (TRPV1); whereas intravenous infusion of chloroquine failed to significantly affect capsaicin-evoked reflexes...
January 6, 2017: American Journal of Physiology. Lung Cellular and Molecular Physiology
https://www.readbyqxmd.com/read/28039190/endurance-training-attenuates-the-increase-in-peripheral-chemoreflex-sensitivity-with-intermittent-hypoxia
#11
Amanda J Miller, Charity L Sauder, Aimee E Cauffman, Cheryl A Blaha, Urs A Leuenberger
Patients with heart failure and sleep apnea have greater chemoreflex sensitivity, presumably due to intermittent hypoxia (IH), and this is predictive of mortality. We hypothesized that endurance training would attenuate the effect of IH on peripheral chemoreflex sensitivity in healthy humans. Fifteen young healthy subjects (9 female, 26 ± 1 yr) participated. Between visits, 11 subjects underwent 8 wk of endurance training that included running four times/wk at 80% predicted maximum heart rate and interval training, and four control subjects did not change activity...
February 1, 2017: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology
https://www.readbyqxmd.com/read/27906839/endothelin-contributes-to-the-blood-pressure-rise-triggered-by-hypoxia-in-severe-obstructive-sleep-apnea
#12
Christophe Janssen, Atul Pathak, Guido Grassi, Philippe van de Borne
BACKGROUND: Obstructive sleep apnea (OSA) is strongly correlated with an increased risk of systemic hypertension. However, the link between systemic hypertension and nocturnal apneas remains incompletely understood. Animal studies suggest an implication of the endothelin system. The aim of the present study is to determine if endogenous endothelin plays a role in the increase in blood pressure observed during hypoxic episodes in OSA patients, in addition to peripheral chemoreflex and neural sympathetic activation...
January 2017: Journal of Hypertension
https://www.readbyqxmd.com/read/27861919/consequences-of-maternal-omega-3-polyunsaturated-fatty-acid-supplementation-on-respiratory-function-in-rat-pups
#13
Luana Tenorio-Lopes, Cécile Baldy, Alexandra Jochmans-Lemoine, Océane Mercier, Olivier Pothier-Piccinin, Tommy Seaborn, Vincent Joseph, Isabelle Marc, Richard Kinkead
KEY POINTS: Incomplete development of the neural circuits that control breathing contributes to respiratory disorders in pre-term infants. Manifestations include respiratory instability, prolonged apnoeas and poor ventilatory responses to stimuli. Based on evidence suggesting that omega-3 polyunsaturated fatty acids (n-3 PUFA) improves brain development, we determined whether n-3 PUFA supplementation (via the maternal diet) improves respiratory function in 10-11-day-old rat pups. n-3 PUFA treatment prolonged apnoea duration but augmented the relative pulmonary surface area and the ventilatory response to hypoxia...
November 11, 2016: Journal of Physiology
https://www.readbyqxmd.com/read/27836648/sex-differences-in-sleep-disordered-breathing-in-adults
#14
REVIEW
Tijana Lozo, Dragana Komnenov, M Safwan Badr, Jason H Mateika
The prevalence of sleep disordered breathing is greater in men compared to women. This disparity could be due to sex differences in the diagnosis and presentation of sleep apnea, and the pathophysiological mechanisms that instigate this disorder. Women tend to report more non-typical symptoms of sleep apnea compared to men, and the presentation of apneic events are more prevalent in rapid compared to non-rapid eye movement sleep. In addition, there is evidence of sex differences in upper airway structure and mechanics and in neural mechanisms that impact on the control of breathing...
November 9, 2016: Respiratory Physiology & Neurobiology
https://www.readbyqxmd.com/read/27815038/phenotypes-in-obstructive-sleep-apnea-a-definition-examples-and-evolution-of-approaches
#15
REVIEW
Andrey V Zinchuk, Mark J Gentry, John Concato, Henry K Yaggi
Obstructive sleep apnea (OSA) is a complex and heterogeneous disorder and the apnea hypopnea index alone can not capture the diverse spectrum of the condition. Enhanced phenotyping can improve prognostication, patient selection for clinical trials, understanding of mechanisms, and personalized treatments. In OSA, multiple condition characteristics have been termed "phenotypes." To help classify patients into relevant prognostic and therapeutic categories, an OSA phenotype can be operationally defined as: "A category of patients with OSA distinguished from others by a single or combination of disease features, in relation to clinically meaningful attributes (symptoms, response to therapy, health outcomes, quality of life)...
October 12, 2016: Sleep Medicine Reviews
https://www.readbyqxmd.com/read/27797160/pathogenesis-of-central-and-complex-sleep-apnoea
#16
REVIEW
Jeremy E Orr, Atul Malhotra, Scott A Sands
Central sleep apnoea (CSA) - the temporary absence or diminution of ventilatory effort during sleep - is seen in a variety of forms including periodic breathing in infancy and healthy adults at altitude and Cheyne-Stokes respiration in heart failure. In most circumstances, the cyclic absence of effort is paradoxically a consequence of hypersensitive ventilatory chemoreflex responses to oppose changes in airflow, that is elevated loop gain, leading to overshoot/undershoot ventilatory oscillations. Considerable evidence illustrates overlap between CSA and obstructive sleep apnoea (OSA), including elevated loop gain in patients with OSA and the presence of pharyngeal narrowing during central apnoeas...
January 2017: Respirology: Official Journal of the Asian Pacific Society of Respirology
https://www.readbyqxmd.com/read/27763697/changes-in-cardiovascular-responses-to-chemoreflex-activation-of-rats-recovered-from-protein-restriction-are-not-related-to-at1-receptors
#17
Renato Willian Martins Sá, Andrea Siqueira Haibara, Paula Magalhães Gomes, Giovana Lopes Aguiar, Rafael Souza Leopoldino Nascimento, Maria Lucia Pedrosa, Andréia Carvalho Alzamora, Lisandra Brandino de Oliveira, Leonardo Máximo Cardoso
What is the central question of this study? In this study, we sought to investigate whether cardiovascular responses to peripheral chemoreflex activation of rats recovered from protein restriction are related to activation of AT1 receptors. What is the main finding and its importance? This study highlights the fact that angiotensinergic mechanisms activated by AT1 receptors do not support increased responses to peripheral chemoreflex activation by KCN in rats recovered from protein restriction. Also, we found that protein restriction led to increased resting ventilation in adult rats, even after recovery...
January 1, 2017: Experimental Physiology
https://www.readbyqxmd.com/read/27756650/breath-holding-test-in-evaluation-of-peripheral-chemoreflex-sensitivity-in-healthy-subjects
#18
Nikita Trembach, Igor Zabolotskikh
: The aim of the study was to determine the feasibility of using a breath-holding test in assessing the sensitivity of the peripheral chemoreflex compared with the single-breath carbon dioxide test. The study involved 48 healthy volunteers between the ages of 18-29 years. The breath-holding test was performed followed by the single-breath carbon dioxide test on the next day. A month after the first tests, these tests were repeated to evaluate their reproducibility The coefficient of variability in the single-breath carbon dioxide test ranged from 0 to 32% with a mean of 10±7%...
January 2017: Respiratory Physiology & Neurobiology
https://www.readbyqxmd.com/read/27753889/ish-nia-os-04-p2x3-receptor-activity-in-the-carotid-body-cb-of-spontaneously-hypertensive-sh-rats-contributes-to-increased-chemoreflex-hypersensitivity-and-hypertension
#19
Wioletta Pijacka, Fiona McBryde, Anthony P Ford, Julian F R Paton
OBJECTIVE: Arterial hypertension is associated with increases in both peripheral chemoreceptor reflex sensitivity and sympathetic nerve activity (SNA). We have shown that CB resection in SH rats reduces arterial pressure (AP; McBryde et al. 2013). Since P2X3 receptors exist in the rat CB and P2X3 receptor activity is associated with afferent hyperreflexia (Ford et al. 2015), we hypothesized that P2X3 receptor would be upregulated in the CB of SH vs normotensive (Wistar) control rats and that a selective P2X3 receptor antagonist (AF-219) would reduce chemoreflex hypersensitivity, AP and SNA in SH rats...
September 2016: Journal of Hypertension
https://www.readbyqxmd.com/read/27746740/moderate-hyperbilirubinemia-alters-neonatal-cardiorespiratory-control-and-induces-inflammation-in-the-nucleus-tractus-solitarius
#20
Marie-Laure Specq, Mélisande Bourgoin-Heck, Nathalie Samson, François Corbin, Christian Gestreau, Maxime Richer, Hazim Kadhim, Jean-Paul Praud
Hyperbilirubinemia (HB) occurs in 90% of preterm newborns. Moderate HB can induce acute neurological disorders while severe HB has been linked to a higher incidence of apneas of prematurity. The present study aimed to test the hypothesis that even moderate HB disrupts cardiorespiratory control in preterm lambs. Two groups of preterm lambs (born 14 days prior to term), namely control (n = 6) and HB (n = 5), were studied. At day 5 of life, moderate HB (150-250 μmol/L) was induced during 17 h in the HB group after which cardiorespiratory control as well as laryngeal and pulmonary chemoreflexes were assessed during baseline recordings and during hypoxia...
2016: Frontiers in Physiology
keyword
keyword
3053
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"