A recent study showed that ergometry increased circulating hematopoietic stem and progenitor cell (CPC) numbers, but reduced hematopoietic colony forming capacity/functionality under normoxia and normobaric hypoxia. Herein we investigated whether an exercise-induced elevated plasma free/bound norepinephrine (NE) concentration could be responsible for directly influencing CPC functionality. Veno...

The cardiovascular response to an arousal occurring at the termination of an obstructive apnea is almost double that to a spontaneous arousal. We investigated the hypothesis that central plus peripheral chemoreceptor stimulation, induced by hypercapnic hypoxia (HH), augments the cardiovascular response to arousal from sleep. Auditory-induced arousals during normoxia and HH (>10-s duration) were...

During acute hypoxia, a hypometabolic response is commonly observed in many newborn and adult mammalian species. We hypothesized that, if hypoxic hypometabolism were entirely a regulated response with no limitation in O2 availability, pharmacological uncoupling of the oxidative phosphorylation should raise O2 consumption (VO2) by similar amounts in hypoxia and normoxia. Metabolic, ventilatory, ...

OBJECTIVE Both a 1- to 4-week continuous or intermittent stay and moderate exercise in hypoxia versus normoxia can lead to weight loss. We examined the reproducibility and durability of added hypoxic exposure in a feasible health program of several months. METHODS 32 obese persons, randomly assigned to either a hypoxia (age 50.3 ± 10.3 years, BMI 37.9 ± 8.1 kg/m(²)) or a normoxia (age 52.4 ± ...

The influence of intensive acute hypoxia on the frequency-amplitude formant vocal O characteristics was investigated in this study. Examinees were exposed to the simulated altitudes of 5,500 m and 6,700 m in climabaro chamber and resolved Lotig's test in the conditions of normoxia, i.e. pronounced the three-digit numbers beginning from 900, but in reversed order. Frequency and intensity values ...

Compromisation of food intake when confronted with diets deficient in essential amino acids is a common response of fish and other animals, but the underlying physiological factors are poorly understood. We hypothesize that oxygen consumption of fish is a possible physiological factor constraining food intake. To verify, we assessed the food intake and oxygen consumption of rainbow trout fed to...

We compared the reactivity of pulmonary vessels to bradykinin (BK) and angiotensin I (AI) in normal and chronically hypoxic rats; the latter have pulmonary hypertension and muscularized pulmonary arterioles. These peptides are respectively inactivated and activated by the angiotensin converting-enzyme (ACE) on pulmonary endothelium. Isolated lungs were perfused at a constant flow rate when chan...

Cytotrophoblast (CT) cells isolated and purified from term placenta are able to differentiate into syncytiotrophoblast cells. Previous reports suggested that hypoxia is an inhibitor of this differentiation and also increases apoptosis. As visual observations of our CT cell cultures indicated a better development in hypoxia than in normoxia (defined as 2.5 and 21% O(2), respectively), we decided...

OBJECTIVE The relative contributions of the fraction of inspired oxygen (FIO2) and atmospheric pressure (ATM) to cardioprotection are unknown. We determined whether the product of FIO2 x ATM (oxygen partial pressure) controls the extent of hyperoxic+hyperbaric-induced cardioprotection and involves activation of nitric oxide synthase (NOS). METHODS Adult Sprague Dawley rats (n = 10/gp) were tr...

Glioblastoma multiforme (GBM) is the most common and aggressive form of brain tumors. GBMs, like other tumors, rely relatively less on mitochondrial oxidative phosphorylation (OXPHOS) and utilize more aerobic glycolysis, and this metabolic shift becomes augmented under hypoxia. In the present study, we investigated the physiological significance of altered glucose metabolism and hypoxic adaptat...