Physiological and Biological Responses to Short-Term Intermittent Hypobaric Hypoxia Exposure: From Sports and Mountain Medicine to New Biomedical Applications

This study tested the hypothesis that athletes exposed to 4 wk of intermittent hypobaric hypoxia exposure (3 h/day, 5 days/wk at 4,000–5,500 m) or double-blind placebo increase their red blood cell volume (RCV) and hemoglobin mass (Hbmass) secondary to an increase in erythropoietin (EPO). Twenty-three collegiate level athletes were measured before (Pre) and after (Post) the intervention for RCV via Evans blue (EB) dye and in duplicate for Hbmassusing CO rebreathing. Hematological indexes including EPO, soluble transferrin receptor, and reticulocyte parameters were measured on 8–10 occasions spanning the intervention. The subjects were randomly divided among hypobaric hypoxia (Hypo, n = 11) and normoxic (Norm, n = 12) groups. Apart from doubling EPO concentration 3 h after hypoxia there was no increase in any of the measures for either Hypo or Norm groups. The mean change in RCV from Pre to Post for the Hypo group was 2.3% (95% confidence limits = −4.8 to 9.5%) and for the Norm group was −0.2% (−5.7 to 5.3%). The corresponding changes in Hbmasswere 1.0% (−1.3 to 3.3%) for Hypo and −0.3% (−2.6 to 3.1%) for Norm. There was good agreement between blood volume (BV) from EB and CO: EB BV = 1.03 × CO BV + 142, r2= 0.85, P < 0.0001. Overall, evidence from four independent techniques (RCV, Hbmass, reticulocyte parameters, and soluble transferrin receptor) suggests that INTERMITTENT HYPOBARIC HYPOXIA EXPOSURE did not accelerate erythropoiesis despite the increase in serum EPO.

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Blood rheological behaviour in rats after intermittent hypobaric hypoxia exposure to 5000 m

Comparative Biochemistry and Physiology Part A Molecular & Integrative Physiology ◽

10.1016/j.cbpa.2007.01.340 ◽

2007 ◽

Vol 146 (4) ◽

pp. S164

Author(s):

S. Esteva ◽

P. Panisello ◽

R. Torrella ◽

T. Pagès ◽

G. Viscor

Keyword(s):

Hypobaric Hypoxia ◽

Rheological Behaviour ◽

Hypoxia Exposure ◽

Intermittent Hypobaric Hypoxia

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The Effect of Intermittent Hypobaric Hypoxia Exposure on Reduced-Glutathione Level in Rat Lung and Renal Tissues

Advanced Science Letters ◽

10.1166/asl.2018.12704 ◽

2018 ◽

Vol 24 (8) ◽

pp. 6249-6251

Author(s):

N. S Hardiany ◽

A. A Asa ◽

D Safirina ◽

W Mulyawan

Keyword(s):

Hypobaric Hypoxia ◽

Reduced Glutathione ◽

Renal Tissue ◽

Rat Lung ◽

Sprague Dawley ◽

Hypoxia Exposure ◽

Intermittent Hypobaric Hypoxia ◽

Sprague Dawley Rats ◽

Adaptation Response ◽

Ellman’S Method

Hypobaric hypoxia is basically a hypoxia condition experienced in high altitude commonly during flight, that increase reactive oxygen species (ROS). When hypoxia hypobaric does not undergo continuation or in other word, intermittent, it will cause adaptation response in a form of protection mode into ROS. Moreover, ROS could be eliminated by reduced-glutathione (GSH) as an endogenous non enzymatic antioxidant. Therefore, the aim of this study was to analyze the effects of intermittent hypobaric hypoxia exposure on GSH level in rat lung and renal tissue. Lung and renal samples were collected from 6–8 weeks old male Sprague-Dawley rats weighing 150–200 g, previously exposed 1–4 times to intermittent hypobaric hypoxia in 35,000 ft (1 minute), 25.000 ft (5 minute) and 18,000 ft altitude (25 minute). Afterwards, GSH level was calculated from lung and renal extracts using the Ellman’s method. In lung tissues, GSH level was decreased in hypoxia 1×, 2×, 3×, 4× treatment, and were significant between the control–hypoxia 3×, control–hypoxia 4×, hypoxia 1×–hypoxia 3× and hypoxia 1×–hypoxia 4×. On the contrary, GSH level was increased in renal tissues on hypoxia 1× and hypoxia 2× treatment compared to control. Nevertheless, GSH level was decreased after 3× treatment and found almost stabilized at 4× treatment of hypoxia in renal tissues. Intermittent hypobaric hypoxia exposure affect GSH in rat lung and renal tissues with varying level as an adaptive response system.

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Intermittent hypobaric hypoxia combined with aerobic exercise improves muscle morphofunctional recovery after eccentric exercise to exhaustion in trained rats

Journal of Applied Physiology ◽

10.1152/japplphysiol.00501.2016 ◽

2017 ◽

Vol 122 (3) ◽

pp. 580-592 ◽

Cited By ~ 8

Author(s):

D. Rizo-Roca ◽

J. G. Ríos-Kristjánsson ◽

C. Núñez-Espinosa ◽

E. Santos-Alves ◽

I. O. Gonçalves ◽

...

Keyword(s):

Aerobic Exercise ◽

Muscle Damage ◽

Eccentric Exercise ◽

Hypobaric Hypoxia ◽

Citrate Synthase ◽

Capillary Density ◽

Oxidative Capacity ◽

Cross Sectional ◽

Hypoxia Exposure ◽

Intermittent Hypobaric Hypoxia

Unaccustomed eccentric exercise leads to muscle morphological and functional alterations, including microvasculature damage, the repair of which is modulated by hypoxia. We present the effects of intermittent hypobaric hypoxia and exercise on recovery from eccentric exercise-induced muscle damage (EEIMD). Soleus muscles from trained rats were excised before (CTRL) and 1, 3, 7, and 14 days after a double session of EEIMD protocol. A recovery treatment consisting of one of the following protocols was applied 1 day after the EEIMD: passive normobaric recovery (PNR), a 4-h daily exposure to passive hypobaric hypoxia at 4,000 m (PHR), or hypobaric hypoxia exposure followed by aerobic exercise (AHR). EEIMD produced an increase in the percentage of abnormal fibers compared with CTRL, and it affected the microvasculature by decreasing capillary density (CD, capillaries per mm2) and the capillary-to-fiber ratio (CF). After 14 days, AHR exhibited CD and CF values similar to those of CTRL animals (789 and 3.30 vs. 746 and 3.06) and significantly higher than PNR (575 and 2.62) and PHR (630 and 2.92). Furthermore, VEGF expression showed a significant 43% increase in AHR when compared with PNR. Moreover, after 14 days, the muscle fibers in AHR had a more oxidative phenotype than the other groups, with significantly smaller cross-sectional areas (AHR, 3,745; PNR, 4,502; and PHR, 4,790 µm2), higher citrate synthase activity (AHR, 14.8; PNR, 13.1; and PHR, 12 µmol·min−1·mg−1) and a significant 27% increment in PGC-1α levels compared with PNR. Our data show that hypoxia combined with exercise attenuates or reverses the morphofunctional alterations induced by EEIMD. NEW & NOTEWORTHY Our study provides new insights into the use of intermittent hypobaric hypoxia combined with exercise as a strategy to recover muscle damage induced by eccentric exercise. We analyzed the effects of hypobaric exposure combined with aerobic exercise on histopathological features of muscle damage, fiber morphofunctionality, capillarization, angiogenesis, and the oxidative capacity of damaged soleus muscle. Most of these parameters were improved after a 2-wk protocol of intermittent hypobaric hypoxia combined with aerobic exercise.

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Expression of Hypoxia-Inducible Factor-1α and Myoglobin in Rat Heart as Adaptive Response to Intermittent Hypobaric Hypoxia Exposure

HAYATI Journal of Biosciences ◽

10.1016/j.hjb.2017.08.010 ◽

2017 ◽

Vol 24 (3) ◽

pp. 131-135

Author(s):

Margaretha Herawati ◽

Wardaya ◽

Wawan Mulyawan ◽

Fanny Septiani Farhan ◽

Frans Ferdinal ◽

...

Keyword(s):

Adaptive Response ◽

Rat Heart ◽

Hypobaric Hypoxia ◽

Hypoxia Inducible Factor ◽

Hypoxia Inducible Factor 1Α ◽

Hypoxia Exposure ◽

Intermittent Hypobaric Hypoxia

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Cellular Uptake and Magneto-Hyperthermia Induced Cytotoxicity using Photoluminescent Fe3O4 Nanoparticle/Si Quantum Dot Hybrids

10.26434/chemrxiv.13138427 ◽

2020 ◽

Author(s):

Morteza Javadi ◽

Van A. Ortega ◽

Alyxandra Thiessen ◽

Maryam Aghajamali ◽

Muhammad Amirul Islam ◽

...

Keyword(s):

Radio Frequency ◽

Biomedical Applications ◽

Short Term ◽

Water Dispersible ◽

Optical Responses ◽

Si Quantum Dot ◽

Real World Applications ◽

Potential Benefits ◽

Low Toxicity ◽

Si Quantum Dots

The design and fabrication of Si-based multi-functional nanomaterials for biological and biomedical applications is an active area of research. The potential benefits of using Si-based nanomaterials are not only due to their size/surface-dependent optical responses but also the high biocompatibility and low-toxicity of silicon itself. Combining these characteristics with the magnetic properties of Fe3O4 nanoparticles (NPs) multiplies the options available for real-world applications. In the current study, biocompatible magnetofluorescent nano-hybrids have been prepared by covalent linking of Si quantum dots to water-dispersible Fe3O4 NPs via dicyclohexylcarbodiimide (DCC) coupling. We explore some of the properties of these magnetofluorescent nano-hybrids as well as evaluate uptake, the potential for cellular toxicity, and the induction of acute cellular oxidative stress in a mast cells-like cell line (RBL-2H3) by heat induction through short-term radio frequency modulation (10 min @ 156 kHz, 500 A). We found that the NPs were internalized readily by the cells and also penetrated the nuclear membrane. Radio frequency activated nano-hybrids also had significantly increased cell death where > 50% of the RBL-2H3 cells were found to be in an apoptotic or necrotic state, and that this was attributable to increased triggering of oxidative cell stress mechanisms.

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