BACKGROUND In patients with acute respiratory distress syndrome, whether inverse ratio ventilation differs from high positive end-expiratory pressure (PEEP) for gas exchange under a similar mean airway pressure has not been adequately examined. The authors used arterial oxygenation, gastric intramucosal partial pressure of carbon dioxide (PiCO(2)), and pH (pHi) to assess whether pressure-contro...

Adenylate kinase (AK) uses one each of Mg-complexed and free adenylates as substrates in both directions of its reaction. It is very active in the mitochondrial intermembrane space (IMS), but is absent from the mitochondrial matrix where low [ADP] upon intensive respiration limits the respiratory rate. AK activity in the IMS is linked to ATP/ADP exchange across the inner mitochondrial membrane ...

Respiratory sinus arrhythmia (RSA) may serve an inherent function in optimizing pulmonary gas exchange efficiency via clustering and scattering of heart beats during the inspiratory and expiratory phases of the respiratory cycle. This study sought to determine whether physiological levels of RSA, enhanced by slow paced breathing, caused more heart beats to cluster in inspiration. In 12 human su...

although sport-physiologists have repeatedly analyzed respiratory gases through exercise, it is relatively new in the cardiovascular field and is obviously more acceptable than standard exercise test, which gives only information about the existence or absence of cardiovascular diseases (cvds). through the new method of exercise test, parameters including aerobic and anaerobic are checked and m...

The osmoregulatory and respiratory responses of male and female Smeringurus mesaensis (Vaejovidae) to prolonged desiccation were measured. No significant effect of sex on mass-loss rates (MLRs) was found. Still, females maintained their haemolymph osmolality when desiccated to 10% mass loss, whereas that of males increased significantly after loss of as little as 5% of initial mass. Females had...

The lungs move air in and out like bellows. Fresh, oxygen-rich air mixes with intrapulmonary air. Oxygen is carried with the circulation and carbon dioxide is excreted with the exhaled air. Various mechanisms maintain the purposeful distribution of ventilation and circulation. Very much of the complicated physiology and pathophysiology is already known, and it has recently become possible to ob...

Background Evidence suggests that women oxidize more fat for fuel at rest than males. Potential sex differences in fuel utilization during exercise remain unclear. Alterations in diet may influence substrate utilization by altering substrate availability and metabolic enzyme activity. Reduced carbohydrate (CHO) intake has been shown to lower respiratory exchange ratio (RER) over time, which may...