The reason for high altitude anorexia is unclear but could involve alterations in the appetite hormones ghrelin and peptide YY (PYY). This study examined the effect of resting and exercising in hypoxia (12.7% O(2); ∼4,000 m) on appetite, energy intake, and plasma concentrations of acylated ghrelin and PYY. Ten healthy males completed four, 7-h trials in an environmental chamber in a random orde...

Adipose tissue-derived stromal cells (ASCs) natively reside in a relatively low-oxygen tension (i.e., hypoxic) microenvironment in human body. Low oxygen tension (i.e., in situ normoxia), has been known to enhance the growth and survival rate of ASCs, which, however, may lead to the risk of tumourigenesis. Here, we investigated the tumourigenic potential of ASCs under their physiological condit...

Whether chronic hypoxia causes angiogenesis in skeletal muscle is controversial. Male Wistar rats, 5--6 wk of age, were kept at constant 12% O(2) for 3 wk, and frozen sections of their postural soleus (SOL), phasic extensor digitorum longus (EDL), and tibialis anterior (TA) muscles were compared with those of normoxic controls. Capillary supply increased in SOL muscles [capillary-to-fiber ratio...

BACKGROUND An animal model mimicking all the factors involved in obstructive sleep apnea (OSA) is useful for investigating mechanisms because the associated comorbidity usually present in such patients is an important limitation. AIM To test the hypothesis that hypoxia/normoxia and respiratory effort have different effects on the induction of inflammatory response and endothelial dysfunction ...

Hemodynamicg, myocardial function, and regional myocardial blood flow (MBF) were measured during acute right ventricular (RV) pressure overload created by inflation of a previously implanted cuff to constrict the pulmonary artery trunk (PAC) in seven closed-chest, anesthetized calves during normoxia (Pad: 90-110 mm Hg) and hypoxia (PaOj ~ 40 mm Hg). MBF was determined by the microsphere method....

Umbilical cord blood (UCB) is an attractive alternative to bone marrow for isolation of mesenchymal stem cells (MSCs) to treat articular cartilage defects. Here, we set out to determine the growth factors (bone morphogenetic protein 2 (BMP-2) and transforming growth factor-β (TGF-β1)) and oxygen tension effects during chondrogenesis of human UCB-MSCs for cartilage engineering. Chondrogenic diff...

We have previously identified a sequence in the 3'-untranslated region (3'-UTR) of erythropoietin (Epo) mRNA which binds a protein(s), erythropoietin mRNA-binding protein (ERBP). A mutant lacking the ERBP binding site (EpoM) was generated. Hep3B cells were stably transfected with a wild-type Epo (EpoWT) cDNA or EpoM cDNA construct located downstream of a promoter of cytomegalovirus. Following i...

Supraspinal fatigue, defined as an exercise-induced decline in force caused by suboptimal output from the motor cortex, accounts for over one-quarter of the force loss after fatiguing contractions of the knee extensors in normoxia. We tested the hypothesis that the relative contribution of supraspinal fatigue would be elevated with increasing severities of acute hypoxia. On separate days, 11 he...

Our aim was to isolate the independent effects of 1) inspiratory muscle work (W(b)) and 2) arterial hypoxemia during heavy-intensity exercise in acute hypoxia on locomotor muscle fatigue. Eight cyclists exercised to exhaustion in hypoxia [inspired O(2) fraction (Fi(O(2))) = 0.15, arterial hemoglobin saturation (Sa(O(2))) = 81 +/- 1%; 8.6 +/- 0.5 min, 273 +/- 6 W; Hypoxia-control (Ctrl)] and at ...

Expansion and shoaling of the Oxygen Minimum Zone (OMZ) in coastal upwelling systems due to climate change can have dire consequences on ecosystem structure productivity. The OMZ restricts habitat range most zooplankton, species with low tolerance hypoxia may suffer physiological stress mortality as a result. During 2013 2014, copepod Acartia tonsa collected off northern Chile was used evaluate...