Peroxynitrite mediates the oxidation of the thiol group of both cysteine and glutathione. This process is associated with oxygen consumption. At acidic pH and a cysteine/peroxynitrite molar ratio of < or = 1.2, there was a single fast phase of oxygen consumption, which increased with increasing concentrations of both cysteine and oxygen. At higher molar ratios the profile of oxygen consumption ...

The major cause of exercise-induced asthma (EIA) is thought to be the drying and cooling of the airways during the 'conditioning' of the inspired air. Nasal breathing increases the respiratory system's ability to warm and humidity the inspired air compared to oral breathing and reduces the drying and cooling effects of the increased ventilation during exercise. This will reduce the severity of ...

We have measured maximal oxygen consumption ([Formula: see text]O2,max) of mice lacking one or two of the established mouse red-cell CO2 channels AQP1, AQP9, and Rhag. We intended to study whether these proteins, by acting as channels for O2, determine O2 exchange in the lung and in the periphery. We found that [Formula: see text]O2,max as determined by the Helox technique is reduced by ~16%, w...

l. Oxygen consumption, ventilation frequency and tidal volume were measured simultaneously in two lizards, Varanus gouldii and Sauromalus hispidus, during rest and maximal activity. 2. Ventilation frequency and tidal volume are almost identical in these species. The greater oxygen consumption during activity of Vat-anus results from a greater oxygen extraction from ventilated air. 3. Increased ...

The relationship between two menstrual cycle phases and cardio respiratory fitness in athletes on oral contraceptives and not on oral contraceptives was assessed in a pilot study. Twelve endurance-trained college cross country runners underwent maximal oxygen consumption treadmill testing, during the late follicular/ovulatory phase and late luteal/premenstrual phase of their menstrual cycle. No...

Background. The acute ingestion of ketone body supplements can improve exercise responses such as oxygen consumption and blood lactate. Additionally, ketone body supplements show increases in circulating βhb concentration, matching those of someone in a state of nutritional ketosis. Studies testing ketone body supplements have reported different results in exercise response and varying gastroin...

Myoglobin binds reversibly with oxygen and can facilitate oxygen diffusion across artificial membranes in vitro (Wittenberg, 1970). Myoglobin-enhanced oxygen consumption in heart is particularly important under conditions of hypoxia. This has been established directly with fish heart models (Bailey & Driedzic, 1986; Driedzic, Stewart & Scott, 1982) and indirectly by following discharge of high-...

The purpose of this study was to develop a valid prediction of maximal oxygen uptake from data collected during a submaximum bench stepping test among children ages 8-12 years. Twentyseven active subjects (16 male and 11 female), weight 36.1 kg, height 144.4 cm and VO2 47.4 ± 7.9 ml/kg/min participated. Subjects completed a maximal oxygen consumption test with analysis of expired air and a subm...