scholarly journals Neuroimmune modulation of cardiorespiratory responses to acute severe hypoxia

2018 ◽  
Vol 103 (6) ◽  
pp. 781-782
Author(s):  
Ken D. O'Halloran
Keyword(s):  
Severe Hypoxia ◽  
Cardiorespiratory Responses ◽  
Neuroimmune Modulation

Cardiorespiratory responses of the common carp (Cyprinus carpio) to severe hypoxia at three acclimation temperatures

2002 ◽  
Vol 205 (6) ◽  
pp. 759-768 ◽  
Author(s):  
J. A. W. Stecyk ◽  
A. P. Farrell
Keyword(s):  
Common Carp ◽  
Cyprinus Carpio ◽  
Cardiovascular Responses ◽  
Severe Hypoxia ◽  
Hypoxic Exposure ◽  
Acclimation Temperature ◽  
Cardiorespiratory Responses ◽  
Common Carp Cyprinus Carpio ◽  
Carp Cyprinus Carpio ◽  
Q10 Values

SUMMARYIn vivo measurements of the cardiovascular responses of anoxia-tolerant teleosts to severe prolonged hypoxia are limited. Here, we report the first direct measurements of cardiac output (Q), heart rate (fH) and stroke volume during prolonged severe hypoxia (<0.3 mg O2 l–1) in common carp (Cyprinus carpio L.) that had been acclimated to 6, 10 and 15°C. While routine Q and fH values varied with temperature under normoxic conditions (Q10 values of 1.7 and 2.6, respectively), severe hypoxic exposure significantly depressed fH and Q to similar minimum values that were largely independent of acclimation temperature (Q10 values of 1.2). In contrast, the duration of cardiac depression and the subsequent time period during which carp could tolerate severe hypoxia were inversely related to acclimation temperature (24 h at 6°C, 6 h at 10°C, and 2.5 h at 6°C). Likewise, respiration rate during hypoxia showed a temperature dependence. An unusual finding was that cardiorespiratory status partially recovered during the latter stages of severe hypoxic exposure. We conclude that the cardiorespiratory responses to severe prolonged hypoxia in common carp involved a mixture of temperature-independent, temperature-dependent and time domain phases.

scholarly journals Cardiorespiratory Responses to 10 Weeks of Exoskeleton-Assisted Overground Walking Training inChronic Nonambulatory Patients with Spinal Cord Injury

Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 5022
Author(s):  
Jae Hyeon Park ◽  
Hyeon Seong Kim ◽  
Seong Ho Jang ◽  
Dong Jin Hyun ◽  
Sang In Park ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Oxygen Consumption ◽  
Exercise Intensity ◽  
Moderate Physical Activity ◽  
Intensity Level ◽  
Cardiorespiratory System ◽  
Cardiorespiratory Responses ◽  
Cord Injury ◽  
Walking Efficiency

Exercise intensity of exoskeleton-assisted walking in patients with spinal cord injury (SCI) has been reported as moderate. However, the cardiorespiratory responses to long-term exoskeleton-assisted walking have not been sufficiently investigated. We investigated the cardiorespiratory responses to 10 weeks of exoskeleton-assisted walking training in patients with SCI. Chronic nonambulatory patients with SCI were recruited from an outpatient clinic. Walking training with an exoskeleton was conducted three times per week for 10 weeks. Oxygen consumption and heart rate (HR) were measured during a 6-min walking test at pre-, mid-, and post-training. Exercise intensity was determined according to the metabolic equivalent of tasks (METs) for SCI and HR relative to the HR reserve (%HRR). Walking efficiency was calculated as oxygen consumption divided by walking speed. The exercise intensity according to the METs (both peak and average) corresponded to moderate physical activity and did not change after training. The %HRR demonstrated a moderate (peak %HRR) and light (average %HRR) exercise intensity level, and the average %HRR significantly decreased at post-training compared with mid-training (31.6 ± 8.9% to 24.3 ± 7.3%, p = 0.013). Walking efficiency progressively improved after training. Walking with an exoskeleton for 10 weeks may affect the cardiorespiratory system in chronic patients with SCI.

scholarly journals Intermittent Hypobaric Hypoxic Preconditioning Provides Neuroprotection by Increasing Antioxidant Activity, Erythropoietin Expression and Preventing Apoptosis and Astrogliosis in the Brain of Adult Rats Exposed to Acute Severe Hypoxia

2021 ◽  
Vol 22 (10) ◽  
pp. 5272
Author(s):  
Débora Coimbra-Costa ◽  
Fernando Garzón ◽  
Norma Alva ◽  
Tiago C. C. Pinto ◽  
Fernando Aguado ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Hypobaric Hypoxia ◽  
Hypoxic Preconditioning ◽  
Severe Hypoxia ◽  
Efficient Tool ◽  
Adult Rats ◽  
Therapeutic Benefits ◽  
Background Exposure ◽  
The Brain ◽  
Apoptotic Cascade

Background: Exposure to intermittent hypoxia has been demonstrated to be an efficient tool for hypoxic preconditioning, preventing damage to cells and demonstrating therapeutic benefits. We aimed to evaluate the effects of respiratory intermittent hypobaric hypoxia (IHH) to avoid brain injury caused by exposure to acute severe hypoxia (ASH). Methods: biomarkers of oxidative damage, mitochondrial apoptosis, and transcriptional factors in response to hypoxia were assessed by Western blot and immunohistochemistry in brain tissue. Four groups of rats were used: (1) normoxic (NOR), (2) exposed to ASH (FiO2 7% for 6 h), (3) exposed to IHH for 3 h per day over 8 days at 460 mmHg, and (4) ASH preconditioned after IHH. Results: ASH animals underwent increased oxidative-stress-related parameters, an upregulation in apoptotic proteins and had astrocytes with phenotype forms compatible with severe diffuse reactive astrogliosis. These effects were attenuated and even prevented when the animals were preconditioned with IHH. These changes paralleled the inhibition of NF-κB expression and the increase of erythropoietin (EPO) levels in the brain. Conclusions: IHH exerted neuroprotection against ASH-induced oxidative injury by preventing oxidative stress and inhibiting the apoptotic cascade, which was associated with NF-κB downregulation and EPO upregulation.

scholarly journals The Effects of Simultaneous Upper and Lower Body Cycling on Cardiorespiratory Responses.

2019 ◽  
Vol 51 (Supplement) ◽  
pp. 994
Author(s):  
Jessica Royen ◽  
Brandi N. Guillotte ◽  
Kierstin Marshall ◽  
Kimberly Billiot ◽  
Robert R. Kraemer
Keyword(s):  
Lower Body ◽  
Cardiorespiratory Responses

570 CARDIORESPIRATORY RESPONSES TO VARIOUS BODY POSITIONS IN COMPETITIVE IN-LINE SKATERS

1994 ◽  
Vol 26 (Supplement) ◽  
pp. S101
Author(s):  
F. J. Fedel ◽  
C. A. Brawner ◽  
C. R.C. Marks ◽  
T. Kataoka ◽  
M. J. Hakim ◽  
...  
Keyword(s):  
Cardiorespiratory Responses

Regulation of cytochrome oxidase redox state during umbilical cord occlusion in preterm fetal sheep

2007 ◽  
Vol 292 (4) ◽  
pp. R1569-R1576 ◽  
Author(s):  
Laura Bennet ◽  
Vincent Roelfsema ◽  
Justin M. Dean ◽  
Guido Wassink ◽  
Gordon G. Power ◽  
...  
Keyword(s):  
Cytochrome Oxidase ◽  
Umbilical Cord ◽  
Redox State ◽  
Cerebral Oxygenation ◽  
Cerebral Metabolism ◽  
Electron Flow ◽  
Initial Response ◽  
Severe Hypoxia ◽  
Fetal Sheep ◽  
Severe Hypotension

The preterm fetus is capable of surviving prolonged periods of severe hypoxia without neural injury for much longer than at term. To evaluate the hypothesis that regulated suppression of brain metabolism contributes to this remarkable tolerance, we assessed changes in the redox state of cytochrome oxidase (CytOx) relative to cerebral heat production, and cytotoxic edema measured using cerebral impedance, during 25 min of complete umbilical cord occlusion or sham occlusion in fetal sheep at 0.7 gestation. Occlusion was followed by rapid, profound reduction in relative cerebral oxygenation and EEG intensity and an immediate increase in oxidized CytOx, indicating a reduction in electron flow down the mitochondrial electron transfer chain. Confirming rapid suppression of cerebral metabolism there was a loss of the temperature difference between parietal cortex and body at a time when carotid blood flow was maintained at control values. As occlusion continued, severe hypotension/hypoperfusion developed, with a further increase in CytOx levels to a plateau between 8 and 13 min and a progressive rise in cerebral impedance. In conclusion, these data strongly suggest active regulation of cerebral metabolism during the initial response to severe hypoxia, which may help to protect the immature brain from injury.

Cardiorespiratory responses to exercise distributed between the upper and lower body

1983 ◽  
Vol 54 (5) ◽  
pp. 1403-1407 ◽  
Author(s):  
M. M. Toner ◽  
M. N. Sawka ◽  
L. Levine ◽  
K. B. Pandolf
Keyword(s):  
Respiratory Exchange Ratio ◽  
Venous Return ◽  
Minute Ventilation ◽  
Peripheral Resistance ◽  
Upper Body ◽  
Lower Body ◽  
Upper Body Exercise ◽  
Cardiorespiratory Responses ◽  
Muscle Groups ◽  
Constant Power Output

The present study examined the influence that distributing exercise between upper (arm crank exercise) and lower (cycle exercise) body muscle groups had on cardiorespiratory responses to constant power output (PO) exercise. Six male volunteers completed five submaximal exercise bouts of 7-min duration at both 76 and 109 W. The arm PO/total PO (% arm) for these bouts was approximately 0, 20, 40, 60, and 100%. At 76 W, O2 uptake (VO2) did not change (P greater than 0.05) from 0 to approximately 20% arm (approximately 1.30 1 x min-1) but increased with increasing percent arm values up to 100% (1.58 1 x min-1). At 109 W, VO2 increased throughout the range of 0 (1.70 1 x min-1) to 100% arm (2.33 1 x min-1). In general, minute ventilation (VE) and respiratory exchange ratio (R) increased with increased percent arm values at 76 and 109 W. The heart rate (HR) responses remained unchanged from 0 to 60% arm at both 76 and 109 W; however, between 60 and 100% arm, a 26-beats x min-1 increase was observed at 76 W (143 beats x min-1 at 100% arm) and a 45-beats x min-1 increase at 109 W (174 beats x min-1 at 100% arm). These data suggested that during upper body exercise, the increased VO2 associated with increased percent arm values was not accompanied by an elevated HR response when at least 40% of the PO was performed by the lower body. This might be attributed to a facilitated venous return and/or a decreased total peripheral resistance when the lower body was involved in the exercise.

Metabolic recovery in goldfish: A comparison of recovery from severe hypoxia exposure and exhaustive exercise

2008 ◽  
Vol 148 (4) ◽  
pp. 332-338 ◽  
Author(s):  
Milica Mandic ◽  
Gigi Y. Lau ◽  
Manu M.S. Nijjar ◽  
Jeffrey G. Richards
Keyword(s):  
Exhaustive Exercise ◽  
Severe Hypoxia ◽  
Hypoxia Exposure ◽  
Metabolic Recovery
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