keyword
MENU ▼
Read by QxMD icon Read
search

acute intermittent hypoxia

keyword
https://www.readbyqxmd.com/read/29775479/acute-intermittent-hypoxia-and-rehabilitative-training-following-cervical-spinal-injury-alters-neuronal-hypoxia-and-plasticity-associated-protein-expression
#1
Atiq Hassan, Breanna M Arnold, Sally Caine, Behzad M Toosi, Valerie M K Verge, Gillian D Muir
One of the most promising approaches to improve recovery after spinal cord injury (SCI) is the augmentation of spontaneously occurring plasticity in uninjured neural pathways. Acute intermittent hypoxia (AIH, brief exposures to reduced O2 levels alternating with normal O2 levels) initiates plasticity in respiratory systems and has been shown to improve recovery in respiratory and non-respiratory spinal systems after SCI in experimental animals and humans. Although the mechanism by which AIH elicits its effects after SCI are not well understood, AIH is known to alter protein expression in spinal neurons in uninjured animals...
2018: PloS One
https://www.readbyqxmd.com/read/29750475/effects-of-losartan-and-allopurinol-on-cardiorespiratory-regulation-in-obstructive-sleep-apnoea
#2
Barbara J Morgan, Mihaela Teodorescu, David F Pegelow, Emily R Jackson, Devin L Schneider, David T Plante, James P Gapinski, Scott J Hetzel, John M Dopp
Chemoreflex sensitization produced by chronic intermittent hypoxia (CIH) in rats is attenuated by angiotensin II type 1 receptor (AT1 R) blockade. AT1 R blockade and xanthine oxidase inhibition both ameliorate CIH-induced endothelial dysfunction. We hypothesized treatment with losartan and allopurinol would reduce chemoreflex sensitivity and improve hypoxic vasodilation in patients with obstructive sleep apnoea (OSA). Eighty-six hypertensive patients with apnoea-hypopnoea index ≥25 events/hr and no other cardiovascular, pulmonary, renal, or metabolic disease were randomly assigned to receive allopurinol, losartan, or placebo for 6 weeks...
May 11, 2018: Experimental Physiology
https://www.readbyqxmd.com/read/29688171/acute-intermittent-hypoxia-enhances-corticospinal-synaptic-plasticity-in-humans
#3
Lasse Christiansen, M A Urbin, Gordon S Mitchell, Monica A Perez
Acute intermittent hypoxia (AIH) enhances voluntary motor output in humans with central nervous system damage. The neural mechanisms contributing to these beneficial effects are unknown. We examined corticospinal function by evaluating motor evoked potentials (MEPs) elicited by cortical and subcortical stimulation of corticospinal axons and the activity in intracortical circuits in a finger muscle before and after 30 min of AIH or sham AIH. We found that the amplitude of cortically and subcortically elicited MEPs increased for 75 min after AIH but not sham AIH while intracortical activity remained unchanged...
April 24, 2018: ELife
https://www.readbyqxmd.com/read/29645283/sympathoexcitation-following-intermittent-hypoxia-in-rat-is-mediated-by-circulating-angiotensin-ii-acting-at-the-carotid-body-and-subfornical-organ
#4
Seung Jae Kim, Angelina Y Fong, Paul M Pilowsky, Stephen B G Abbott
KEY POINTS: In anaesthetized rats, acute intermittent hypoxia increases sympathetic nerve activity, sympathetic peripheral chemoreflex sensitivity and central sympathetic-respiratory coupling. Renin-angiotensin system inhibition prevents the sympathetic effects of intermittent hypoxia, with intermittent injections of angiotensin II into the systemic circulation replicating these effects. Bilateral carotid body denervation reduces the sympathetic effects of acute intermittent hypoxia and eliminates the increases in chemoreflex sensitivity and sympathetic-respiratory coupling...
April 12, 2018: Journal of Physiology
https://www.readbyqxmd.com/read/29623044/long-term-intermittent-work-at-high-altitude-right-heart-functional-and-morphological-status-and-associated-cardiometabolic-factors
#5
Julio Brito, Patricia Siques, Rosario López, Raul Romero, Fabiola León-Velarde, Karen Flores, Nicole Lüneburg, Juliane Hannemann, Rainer H Böger
Background: Living at high altitude or with chronic hypoxia implies functional and morphological changes in the right ventricle and pulmonary vasculature with a 10% prevalence of high-altitude pulmonary hypertension (HAPH). The implications of working intermittently (day shifts) at high altitude (hypobaric hypoxia) over the long term are still not well-defined. The aim of this study was to evaluate the right cardiac circuit status along with potentially contributory metabolic variables and distinctive responses after long exposure to the latter condition...
2018: Frontiers in Physiology
https://www.readbyqxmd.com/read/29584516/effect-of-intermittent-hypoxia-training-for-dizziness-a-randomized-controlled-trial
#6
Xiao Bao, Jie-Wen Tan, Ying Long, Howe Liu, Hui-Yu Liu
OBJECTIVE: To study the effect of intermittent hypoxia training (IHT) for dizziness. DESIGN: A single-blind, randomized controlled trial. All participants were recruited from a rehabilitation department in an acute university-affiliated hospital. INTERVENTION: Participants with dizziness were randomly assigned to two groups (IHT group and control group). The Dizziness Handicap Inventory (DHI), Activities-specific Balance Confidence Scale (ABC), Vertigo Visual Analog Scale (VVAS) were conducted at baseline, end of the 4th week...
March 27, 2018: Journal of Sport Rehabilitation
https://www.readbyqxmd.com/read/29565772/il-1-receptor-activation-undermines-respiratory-motor-plasticity-after-systemic-inflammation
#7
Austin D Hocker, Adrianne Genest Huxtable
Inflammation undermines respiratory motor plasticity, yet we are just beginning to understand the inflammatory signaling involved. Since interleukin-1 (IL-1) signaling promotes or inhibits plasticity in other CNS regions, we tested the following hypotheses: 1) IL-1 receptor (IL-1R) activation after systemic inflammation is necessary to undermine phrenic long-term facilitation (pLTF), a model of respiratory motor plasticity induced by acute intermittent hypoxia (AIH), and 2) spinal IL-1β is sufficient to undermine pLTF...
March 22, 2018: Journal of Applied Physiology
https://www.readbyqxmd.com/read/29541032/the-influence-of-co-2-and-exercise-on-hypobaric-hypoxia-induced-pulmonary-edema-in-rats
#8
Ryan L Sheppard, Joshua M Swift, Aaron Hall, Richard T Mahon
Introduction: Individuals with a known susceptibility to high altitude pulmonary edema (HAPE) demonstrate a reduced ventilation response and increased pulmonary vasoconstriction when exposed to hypoxia. It is unknown whether reduced sensitivity to hypercapnia is correlated with increased incidence and/or severity of HAPE, and while acute exercise at altitude is known to exacerbate symptoms the effect of exercise training on HAPE susceptibility is unclear. Purpose: To determine if chronic intermittent hypercapnia and exercise increases the incidence of HAPE in rats...
2018: Frontiers in Physiology
https://www.readbyqxmd.com/read/29528458/effects-of-low-oxygen-during-chorioallantoic-membrane-development-on-post-hatch-growing-performance-of-broiler-chickens
#9
S Druyan, M Ruzal, D Shinder, A Haron
The prenatal circulatory system is adaptive and capable of plasticity designed for the needs of the growing tissue. When a broiler embryo is faced with hypoxic stress, the process of angiogenesis in tissues begins. Exposure to hypoxic conditions of 17% oxygen during the chorioallantoic membrane (CAM) development (E5 to E12) affected the circulatory system and contributed to an increase in the blood oxygen carrying capacity. The present study aimed to evaluate the effects of hypoxic exposure during CAM development on post-hatch performance of broilers and to examine whether hypoxic exposure improved sustainability of birds exposed to acute heat stress...
June 1, 2018: Poultry Science
https://www.readbyqxmd.com/read/29513151/systemic-inflammation-inhibits-serotonin-receptor-2-induced-phrenic-motor-facilitation-upstream-from-bdnf-trkb-signaling
#10
Ibis M Agosto, Nicole L Nichols, Gordon S Mitchell
Although systemic inflammation induced by even a low dose of lipopolysaccharide (LPS, 100uL/kg) impairs respiratory motor plasticity, little is known concerning cellular mechanisms giving rise to this inhibition. Phrenic motor facilitation (pMF) is a form of respiratory motor plasticity elicited by pharmacological agents applied to the cervical spinal cord, or by acute intermittent hypoxia (AIH; 3, 5 min hypoxic episodes); when elicited by AIH, pMF is known as phrenic long-term facilitation (pLTF). AIH consisting of moderate hypoxic episodes (mAIH, PaO2 = 35-55 mmHg) elicits pLTF via the Q- pathway to pMF, a mechanism that requires spinal serotonin (5HT2) receptor activation and new BDNF protein synthesis...
March 7, 2018: Journal of Neurophysiology
https://www.readbyqxmd.com/read/29466787/a-strategy-for-optimizing-the-combination-of-active-components-based-on-chinese-medicinal-formula-sheng-mai-san-for-myocardial-ischemia
#11
Fang Li, Xiao-Xue Fan, Chun Chu, Yu Zhang, Jun-Ping Kou, Bo-Yang Yu
BACKGROUND/AIMS: Traditional Chinese medicine (TCM) has been used in clinical practice for thousands of years and has accumulated considerable knowledge concerning the in vivo efficacy of targeting complicated diseases. TCM formulae are a mixture of hundreds of chemical components with multiple potential targets, essentially acting as a combination therapy of multi-component drugs. However, the obscure substances and the unclear molecular mechanisms are obstacles to their further development and internationalization...
2018: Cellular Physiology and Biochemistry
https://www.readbyqxmd.com/read/29423544/high-intensity-interval-training-in-hypoxia-does-not-affect-muscle-hif-responses-to-acute-hypoxia-in-humans
#12
Stefan De Smet, Gommaar D'Hulst, Chiel Poffé, Ruud Van Thienen, Emanuele Berardi, Peter Hespel
PURPOSE: The myocellular response to hypoxia is primarily regulated by hypoxia-inducible factors (HIFs). HIFs thus conceivably are implicated in muscular adaptation to altitude training. Therefore, we investigated the effect of hypoxic versus normoxic training during a period of prolonged hypoxia ('living high') on muscle HIF activation during acute ischaemia. METHODS: Ten young male volunteers lived in normobaric hypoxia for 5 weeks (5 days per week, ~ 15.5 h per day, Fi O2 : 16...
April 2018: European Journal of Applied Physiology
https://www.readbyqxmd.com/read/29373484/mechanisms-of-cardiovascular-protection-associated-with-intermittent-hypobaric-hypoxia-exposure-in-a-rat-model-role-of-oxidative-stress
#13
Miguel Aguilar, Alejandro González-Candia, Jorge Rodríguez, Catalina Carrasco-Pozo, Daniel Cañas, Claudio García-Herrera, Emilio A Herrera, Rodrigo L Castillo
More than 140 million people live and works (in a chronic or intermittent form) above 2500 m worldwide and 35 million live in the Andean Mountains. Furthermore, in Chile, it is estimated that 55,000 persons work in high altitude shifts, where stays at lowlands and interspersed with working stays at highlands. Acute exposure to high altitude has been shown to induce oxidative stress in healthy human lowlanders, due to an increase in free radical formation and a decrease in antioxidant capacity. However, in animal models, intermittent hypoxia (IH) induce preconditioning, like responses and cardioprotection...
January 26, 2018: International Journal of Molecular Sciences
https://www.readbyqxmd.com/read/29357503/the-hypothalamic-pvn-contributes-to-acute-intermittent-hypoxia-induced-sympathetic-but-not-phrenic-long-term-facilitation
#14
Megan Bardgett Blackburn, Mary Ann Andrade, Glenn M Toney
Acute intermittent hypoxia (AIH) repetitively activates the arterial chemoreflex and triggers a progressive increase of sympathetic nerve activity (SNA) and phrenic nerve activity (PNA) referred to as sympathetic and phrenic long-term facilitation (S-LTF and P-LTF), respectively. Neurons of the hypothalamic paraventricular nucleus (PVN) participate in the arterial chemoreflex, but their contribution to AIH-induced LTF is unknown. To determine this, anesthetized rats were vagotomized and exposed to 10 cycles of AIH, each consisting of ventilation for 3 minutes with 100% O2 followed by 3 minutes with 15% O2 ...
December 21, 2017: Journal of Applied Physiology
https://www.readbyqxmd.com/read/29233741/cyclooxygenase-enzyme-activity-does-not-impair-respiratory-motor-plasticity-after-one-night-of-intermittent-hypoxia
#15
Adrianne G Huxtable, Elizabeth Kopp, Brendan J Doughtery, Jyoti J Watters, Gordon S Mitchell
Although inflammation is prevalent in many clinical disorders challenging breathing, we are only beginning to understand the impact of inflammation on neural mechanisms of respiratory control. We recently demonstrated one form of respiratory motor plasticity is extremely sensitive to even mild inflammation induced by a single night (8 h) of intermittent hypoxia (IH-1), mimicking aspects of obstructive sleep apnea. Specifically, phrenic long-term facilitation (pLTF) following moderate acute intermittent hypoxia (AIH) is abolished by IH-1, but restored by high doses of the non-steroidal anti-inflammatory drug, ketoprofen...
December 9, 2017: Respiratory Physiology & Neurobiology
https://www.readbyqxmd.com/read/29220311/quantifying-the-effects-of-acute-hypoxic-exposure-on-exercise-performance-and-capacity-a-systematic-review-and-meta-regression
#16
Sanjoy K Deb, Daniel R Brown, Lewis A Gough, Christopher P Mclellan, Paul A Swinton, S Andy Sparks, Lars R Mcnaughton
OBJECTIVE: To quantify the effects of acute hypoxic exposure on exercise capacity and performance, which includes continuous and intermittent forms of exercise. DESIGN: A systematic review was conducted with a three-level mixed effects meta-regression. The ratio of means method was used to evaluate main effects and moderators providing practical interpretations with percentage change. DATA SOURCES: A systemic search was performed using three databases (Google scholar, PubMed and SPORTDiscus)...
March 2018: European Journal of Sport Science
https://www.readbyqxmd.com/read/29212793/pacap-6-38-or-kynurenate-microinjections-in-the-rvlm-prevent-the-development-of-sympathetic-long-term-facilitation-after-acute-intermittent-hypoxia
#17
Zohra M Kakall, Paul M Pilowsky, Melissa M J Farnham
Intermittent hypoxia causes a persistent increase in sympathetic activity that progresses to hypertension in chronic conditions such as obstructive sleep apnea. Pituitary adenylate cyclase-activating polypeptide (PACAP) is an excitatory neurotransmitter that causes long-lasting sympathetic excitation. We aimed to determine if intermittent activation of the rostral ventrolateral medulla (RVLM) causes PACAP-mediated elevation of sympathetic nerve activity, termed sympathetic long-term facilitation (sLTF). The role of PACAP in mediating sLTF in response to intermittent activation of the RVLM was investigated in urethane-anaesthetized and artificially ventilated rats ( n = 65, Sprague-Dawley)...
March 1, 2018: American Journal of Physiology. Heart and Circulatory Physiology
https://www.readbyqxmd.com/read/29159869/acute-intermittent-hypoxia-with-concurrent-hypercapnia-evokes-p2x-and-trpv1-receptor-dependent-sensory-long-term-facilitation-in-na%C3%A3-ve-carotid-bodies
#18
Arijit Roy, Melissa M J Farnham, Fatemeh Derakhshan, Paul M Pilowsky, Richard J A Wilson
KEY POINTS: Activity-dependent plasticity can be induced in carotid body (CB) chemosensory afferents without chronic intermittent hypoxia (CIH) preconditioning by acute intermittent hypoxia coincident with bouts of hypercapnia (AIH-Hc). Several properties of this acute plasticity are shared with CIH-dependent sensory long-term facilitation (LTF) in that induction is dependent on 5-HT, angiotensin II, protein kinase C and reactive oxygen species. Several properties differ from CIH-dependent sensory LTF; H2 O2 appears to play no part in induction, whereas maintenance requires purinergic P2X2/3 receptor activation and is dependent on transient receptor potential vanilloid type 1 (TRPV1) receptor sensitization...
November 21, 2017: Journal of Physiology
https://www.readbyqxmd.com/read/29130497/ubc-nepal-expedition-acclimatization-to-high-altitude-increases-spinal-motoneurone-excitability-during-fatigue-in-humans
#19
Luca Ruggiero, Alexandra F Yacyshyn, Jane Nettleton, Chris J McNeil
KEY POINTS: Acute exposure and acclimatization to hypoxia are associated with an impairment and partial recovery, respectively, of the capability of the central nervous system to drive muscles during prolonged efforts. Motoneurones play a vital role in muscle contraction and in fatigue, although the effect of hypoxia on motoneurone excitability during exercise has not been assessed in humans. We studied the impact of fatigue on motoneurone excitability in normoxia, acute and chronic exposure (5050 m) to hypoxia...
November 11, 2017: Journal of Physiology
https://www.readbyqxmd.com/read/29107023/intermittent-hypoxia-alters-dose-dependent-caffeine-effects-on-renal-prostanoids-and-receptors-in-neonatal-rats
#20
Kay D Beharry, Charles L Cai, Kultida Soontarapornchai, Taimur Ahmad, Gloria B Valencia, Jacob V Aranda
Caffeine, one of the most commonly prescribed drugs in preterm neonates, is given in standard or suprapharmacologic doses. Although known as a diuretic, its effects in the neonatal kidneys are not well studied. We tested the hypothesis that neonatal intermittent hypoxia (IH) and high caffeine doses (HCD) alter renal regulators of vasomotor tone and water balance. Newborn rats were randomized to room air, hyperoxia, or IH and treated with standard or high caffeine doses; or placebo saline. Renal prostanoids; histopathology; and cyclooxygenase (COX), prostanoid receptor, and aquaporin (AQP) immunoreactivity were determined...
January 2018: Prostaglandins & Other Lipid Mediators
keyword
keyword
37372
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"