Search results for "consumption"
showing 10 items of 1796 documents
Regulation of Oxygen Distribution in Tissues by Endothelial Nitric Oxide
2009
Nitric oxide (NO) decreases cellular oxygen (O 2 ) consumption by competitively inhibiting cytochrome c oxidase. Here, we show that endogenously released endothelial NO, either basal or stimulated, can modulate O 2 consumption both throughout the thickness of conductance vessels and in the microcirculation. Furthermore, we have shown that such modulation regulates O 2 distribution to the surrounding tissues. We have demonstrated these effects by measuring O 2 consumption in blood vessels in a hypoxic chamber and O 2 distribution in the microcirculation using the fluorescent oxygen-probe Ru(phen) 3 2+ . Removal of NO by physical or pharmacological means, or in eNOS −/− mice, abolishes this …
The Role of Tumor Volume in ‘Reoxygenation’ upon Cyclophosphamide Treatment
1995
The effect of cyclophosphamide (CP) injection (60 mg/kg i.p., single dose) on volume growth and tissue oxygenation (pO2 distribution) was investigated in rat DS-sarcomas. CP was administered 4 days after subcutaneous (s.c.) tumor implantation (volume approximately 0.35 ml). Polarographic pO2 measurements were performed in the subcutis at the hind foot dorsum and in tumors 72 h after CP administration. The oxygenation status of these tissues was compared with that of saline-treated controls. CP-injection caused a mean growth delay of 11 days in DS-sarcomas and had no impact on the oxygenation status of the subcutis. In contrast, in s.c. growing DS-sarcomas the pO2 distribution improved signi…
Fast-food consumption and body mass index in children and adolescents: an international cross-sectional study.
2014
OBJECTIVE: To investigate whether reported fast-food consumption over the previous year is associated with higher childhood or adolescent body mass index (BMI). DESIGN: Secondary analysis from a multicentre, multicountry cross-sectional study (International Study of Asthma and Allergies in Children (ISAAC) Phase Three). SUBJECTS AND METHODS: Parents/guardians of children aged 6-7 completed questionnaires which included questions about their children's asthma and allergies, fast-food consumption, height and weight. Adolescents aged 13-14 completed the same questionnaire. The questionnaire asked 'In the past 12 months, how often on average did you (your child) eat fast-food/burgers?' The resp…
Effects of nicotinamide adenine dinucleotide hydride on physical and mental performance
2007
The aim of this study was to assess the effects of nicotinamide adenine dinucleotide hydride (NADH) on maximal oxygen uptake (VO2max), maximal anaerobic running time, and mental performance. Eight men were exposed to a supplement treatment (30 mg NADH as ENACHI tablets per day) and to a placebo treatment, each of 4 weeks' duration, in a balanced, double-blind, and cross-over design. The two treatments were separated by a 14-week wash-out period. The results indicated that VO2max, maximal anaerobic running time, and the ability to concentrate were similar in the NADH and placebo conditions. There were also no differences in blood lactate, creatine kinase, reaction time or feelings of fatigue…
The cadence and water temperature effect on physiological responses during water cycling
2013
The aim of the study was to compare the maximal physiological responses during three protocols: maximal test on land cycle ergometer, maximal test on water cycling in an indoor pool at 27 °C (WC27) and at 31 °C (WC31). Moreover, the submaximal physiological responses were compared according cycling cadences and water temperatures during the water protocols. Ten young men were included and performed the protocols in separate days. Blood lactate (BL) concentration, heart rate (HR), oxygen uptake (VO2), ventilation (VE) and thermal comfort (TC) were collected during the exercise. The maximal HR and VO2 showed no significant differences between the protocols: HRmax: 189 ± 7 (Land), 188 ± 14 (WC…
Ultra Trail Performance is Differently Predicted by Endurance Variables in Men and Women
2020
AbstractThe study aimed to assess the relationship between peak oxygen uptake, ventilatory thresholds and maximal fat oxidation with ultra trail male and female performance. 47 athletes (29 men and 18 women) completed a cardiopulmonary exercise test between 2 to 4 weeks before a 107-km ultra trail. Body composition was also analyzed using a bioelectrical impedance weight scale. Exploratory correlation analyses showed that peak oxygen uptake (men: r=–0.63, p=0.004; women: r=–0.85, p < 0.001), peak speed (men: r=–0.74, p < 0.001; women: r=–0.69, p=0.009), speed at first (men: r=–0.49, p=0.035; women: r=–0.76, p=0.003) and second (men: r=–0.73, p < 0.001; women: r=–0.76, p=0.003) vent…
Aerobic fitness, energy balance, and body mass index are associated with training load assessed by activity energy expenditure
2009
The present study examined whether activity energy expenditure related to body mass (AEE/kg) is associated with maximal aerobic fitness (VO(2max)), energy balance, and body mass index (BMI) during the 2 hardest weeks of the military basic training season (BT). An additional purpose was to study the accuracy of the pre-filled food diary energy intake. Energy expenditure (EE) with doubly labeled water, energy intake (EI), energy balance, and mis-recording was measured from 24 male conscripts with varying VO(2max). AEE/kg was calculated as (EE x 0.9-measured basal metabolic rate)/body mass. The reported EI was lower (P<0.001) than EE (15.48 MJ/day) and mis-recording of the pre-filled diary …
Associations of cardiorespiratory fitness, physical activity, and BMI with arterial health in middle‐aged men and women
2020
Abstract We investigated the associations of cardiorespiratory fitness (CRF), physical activity (PA) with regard to aerobic and resistance training, and body mass index (BMI) with pulse wave velocity (PWV) and augmentation index (AIx) in middle‐aged adults with at least one cardiovascular risk factor. A total of 84 (46 men and 38 women) participated in the study. Cardiorespiratory fitness was measured using a maximal graded exercise test on a cycle ergometer and was defined as maximal power output (Wmax) normalized for body weight‐0.35. Participation in aerobic and resistance training was assessed by a detailed questionnaire and BMI was calculated as weight (kg)/[height (m2)]. Pulse wave ve…
Aerobic performance capacity in athletes
1978
Maximal oxygen uptake (max\(\dot V\)O2) in leg and arm work, succinate dehydrogenase activity (SDH) and percentage of slow twitch fibers (%ST fibers) in M. vastus lateralis (VL), M. gastrocnemius c.l. (GL) and M. deltoideus (D) were studied in 89 athletes practising 11 different sport events. It was found that maximal oxygen uptake correlated positively with %ST fibers and SDH activity in M. VL. The SDH activity and %ST fibers in M. VL correlated also with one another. The results suggest that oxidative capacity of the muscles is not the limiting factor for maximal oxygen uptake. The role of the oxidative capacity of the muscles might be important during submaximal work of long duration and…
ACTIONS OF PROSTAGLANDIN E2 ON MYOCARDIAL MECHANICS, CORONARY VASCULAR RESISTANCE AND OXYGEN CONSUMPTION IN THE GUINEA-PIG ISOLATED HEART PREPARATION
1975
Abstract 1 In isolated, electrically driven (3 Hz) hearts of guinea-pigs the action of prostaglandin E2 on left ventricular pressure (LVP), oxygen consumption (Qo2) and coronary vascular resistance (CVR) was studied by establishing cumulative concentration-response curves. The hearts were perfused at a constant flow (10 ml/min) with Tyrode solution (Ca++ 1.8 mM) at 32 degrees C. 2 Under control conditions prostaglandin E2 (2.86 X10(-11) -1.43 X 10(-7) M) decreased LVP, QO2 and CVR in a concentration-dependent manner by maximally 27, 18 and 38%, respectively (P less than 0.05). 3 After reserpine pretreatment there were lower initial values for all parameters measured. The effect of prostagla…