Energy Metabolism ; Humans ; Oxygen Consumption ; Walking ; physiology ; Weight-Bearing ; physiology

OBJECTIVETo establish a method for real-time recording the oxygen consumption of mice under normobaric hypoxia.

METHODSThe experimental apparatus was made up of animal container, filling water control system, electronic balance, hose, a computer with weight recording software, etc. The working principle was that the oxygen consumed by animal was replaced by water filling which was controlled by the pneumatic and hydraulic actuator. The water was weighted by an electronic balance and the weight signal was recorded into excel file at the same time. The accuracy and precision of the apparatus were detected by a 10 ml syringe. The oxygen consumption characteristics of 6 acute repetitive hypoxia mice and 6 normal mice were observed.

RESULTSThe P value for the paired t test was 1 and the CV value was 4%. The survival time and total oxygen consumption of acute repetitive hypoxia mice were both significantly increased compared to normal mice (P < 0.05), which were (58.8 +/- 6.8) min and (46.0 +/- 8.7) min respectively for the survival time and (85.1 +/- 8.5) ml and (73.6 +/- 5.4) ml respectively for total oxygen consumption.

CONCLUSIONThe hypoxia tolerance of the acute repetitive hypoxia mice can significantly improved by taking more oxygen in the animal cabin. The accuracy and precision of the apparatus are high and it can be used for the determination of oxygen consumption in hypoxia research.

Animals ; Hypoxia ; physiopathology ; Mice ; Monitoring, Physiologic ; instrumentation ; Oxygen Consumption ; physiology

Body Mass Index ; Female ; Humans ; Male ; Oxygen ; metabolism ; Oxygen Consumption ; physiology ; Sports ; physiology

OBJECTIVETo study the oxygen consumption rate and suffocation point of Whitmania pigra.

METHODUsing the method of respiratory chamber, the oxygen consumption rate, oxygen consumption volume and suffocation point were obtained.

RESULTThe oxygen consumption rate(OCR) ranged from 0.049 to 0.094 mg x g(-1) x h(-1), the oxygen consumption volume(OCV) from 0.44 to 0.67 mg x p(-1) x h(-1), and suffocation point(SP) from 0.9 to 1.51 mg x L(-1), when the average weight of W. pigra was 10 g and the water temperature varied from 15 to 35 degrees C. OCR ranged from 0.044 to 0.058 mg x g(-1) x h(-1), OCV from 0.19 to 0.77 mg x p(-1) x h(-1) and SP from 1.4 to 1.57 mg x l(-1) when water temperature was 20 degrees C.

CONCLUSIONOCR rose when the water temperature and weight increased, but SP was justly opposite. The weight was negatively correlated with OCR and positively with OCV. OCR had little difference from day to night.

Animals ; Leeches ; metabolism ; physiology ; Oxygen ; metabolism ; Oxygen Consumption ; physiology ; Temperature ; Water

Adolescent ; Exercise Tolerance ; physiology ; Female ; Humans ; Male ; Oxygen Consumption ; physiology ; Swimming ; physiology ; Young Adult

Animals ; Humans ; Oxidative Stress ; Oxygen Consumption ; physiology ; Plants ; metabolism ; Reactive Oxygen Species ; metabolism

In order to assess the constituent ratios of energy expenditure in human, the deductive process of establishing a mathematical model for assessing the constituent ratios of the three major nutrients in energy expenditure in human was described in this paper. Total oxygen consumption, total carbon dioxide output and total nitrogen (urine nitrogen + skin nitrogen) excretion are related to the oxidation of the three major nutrients and the physiological combustion values of the three nutrients are already known. Based on these measurable and known parameters, the mathematical model established by the authors will help understand the characteristics of the tested individual's energy expenditure.
Carbon Dioxide ; analysis ; Energy Metabolism ; physiology ; Humans ; Models, Theoretical ; Nutritional Physiological Phenomena ; physiology ; Oxygen Consumption

BACKGROUNDInner retinal oxygenation response (ΔPO(2)) is a worldwide study focus. However, the relevant reports on its radiological measurements are limited. In this study, magnetic resonance imaging (MRI), employing T1 weighted image (T1WI), was used to detect changes in ΔPO(2) following 100% oxygen inhalation in human subjects.

METHODSMRI was performed on a 1.5-T GE scanner system. After obtaining ophthalmologic data, eleven healthy individuals were given room air and 100% oxygen inhalation in order with different intervals. The MRI T1WI data were collected for 50 minutes. Data were analyzed with NIH IMAGE software.

RESULTSΔPO(2) was not panretinally uniform, and changes in oxygenation response were spatially inhomogeneous. During the initial phase (before 5 minutes) of 100% oxygen inhalation, preretinal vitreous water signals in the region of papilla optica increased rapidly. On the contrary, in other regions signals declined. In a later period (35 minutes), ΔPO(2) was panretinally fluctuated and increased slowly and attained homeostasis. After hyperoxia (45 minutes), delayed-enhancement of preretinal vitreous water signals in regions other than the papilla optica occurred, and then dropped down. There was no significant difference (P > 0.05) at any consecutive time point during and after hyperoixa.

CONCLUSIONSThese results reveal that hyperoxia can induce region-specific signal changes in preretinal vitreous water. Regulatory activity of the retinal vessel network may be the mechanism during 100% oxygen inhalation. Moreover, MRI is a valuable tool for investigating ΔPO(2) and exploring the mechanism of retinal oxygenation response physiologically or pathologically in vivo.

Adult ; Female ; Humans ; Magnetic Resonance Imaging ; methods ; Male ; Oxygen Consumption ; physiology ; Retina ; physiology ; Young Adult

OBJECTIVEThe studies were carried out on the physiologic characteristics of Panax notoginseng seeds during the after--ripening process in order to understand the seed's biochemical and physiological changes and lay the foundation for the germplasm conversation and breeding research of P. notoginseng seeds.

METHODDynamic changes of storage material contents, respiratory rate and protective enzymatic activity were determined by normal biochemical and physiological measuring methods.

RESULTThe respiratory rate increased continuously during the stratification process, the contents of starch, soluble protein, crude fat decreased and the content of water-soluble saccharide increased with the embryo development, activities of CAT, POD and SOD increased with the raise of MDA content.

CONCLUSIONP. notoginseng seed's biochemical and physiological changes interacted with its embryo morphological changes to complete its after-ripening development.

Catalase ; metabolism ; Oxygen Consumption ; Panax notoginseng ; chemistry ; physiology ; Seeds ; growth & development ; Superoxide Dismutase ; metabolism

OBJECTIVE: To explore aerobic power and energy expenditure of high level rugby players in China, which provide experimental basis for accurate training and nutritional strategy in match-play. METHODS: Eighteen master rugby players were selected as research subjects. The parameters such as VOmax, lactic aicd threshold (LT) and modify conconi test were measured respectively. The differences of energy were compared between the forward and the defender. The data were analyzed by independent sample t test. RESULTS: The VOmax(42.05±3.69 ml/min ·kg) of rugby players was poorer. The VOmax of the forward was 38.83±3.52 (ml/min ·kg), and that of the defender was 47.31±3.17 (ml/min ·kg),and there was significant difference between the forwards and the defenders (P＜0.05). The LT of the defenders was obviously higher than that of the forwards. Modifier conconi test had a high correlation (r = 0.772) with VOmax. The average energy consumption in the first half of the game was about(276.94±18.08)kcals, the second half was(225.58±22.86)kcals, and the second half was less than the first half (P＜0.05). CONCLUSION The aerobic power is different between the forwards and the defenders. The power of aerobic of Chinese players is weaker than that of the foreign rugby players.
Asian Continental Ancestry Group ; Athletes ; China ; Energy Metabolism ; Football ; physiology ; Humans ; Oxygen Consumption