Previous studies demonstrated that angiotensin II (ANG II) decreases body weight. This study examined whether ANG II regulates body weight through energy expenditure. Acute ANG II administration decreased oxygen consumption. To determine whether this effect was maintained, rats were infused with ANG II or saline for 14 days. Oxygen consumption was transiently decreased on day 1 of ANG II infusi...

Convenient methods were developed for measuring maximum oxygen consumption (VO2 max) in untrained small mammals during treadmill exercise and cold exposure. Deer mice (Peromyscus maniculatus) were run once, for 6-min periods at velocities exceeding maximal aerobic running speed, while instantaneous oxygen consumption was measured. The VO2 max during cold exposure was determined using high wind ...

Previously we have demonstrated that an accelerated arm ergometry testing protocol results in a higher peak oxygen consumption than continuous or discontinuous protocols reported in the literature (Brit. J. Sports Med. 20: 25-26, 1986). The purpose of this investigation was to determine if an accelerated protocol was superior to two commonly used protocols in cycle ergometry. Nine male subjects...

Perinatal inflammation is associated with adverse neurodevelopmental outcomes, which may be partly due to changes in the cerebral oxygen delivery/consumption relationship. We aimed to determine the critical oxygen delivery threshold of the brain of preterm, ventilated lambs and to determine whether the critical threshold is affected by exposure to inflammation in utero. Pregnant ewes received i...

Critical ill patients experience acute physiological changes because the body cannot fulfill the oxygen demand to perform normal aerobic metabolism. Factors determining oxygen delivery include cardiac output, hemoglobin, and oxygen saturation. Incapability to fulfill adequate oxygen of the body to produce adenosine triphosphate (ATP) may occur due to decreased oxygen delivery and/or increased o...

OBJECTIVE To investigate the rate and mechanism of oxygen consumption by the vitreous. METHODS Oxygen consumption was measured with a microrespirometer. Vitreous ascorbate was measured spectrophotometrically and by gas chromatography-mass spectrometry. Vitreous degeneration was related to the rate of oxygen consumption and ascorbate concentration in samples obtained during vitrectomy. RESUL...

The area and thickness of respiratory surfaces, and the constraints they impose on passive oxygen diffusion, have been linked to differences in oxygen consumption rates and/or aerobic activity levels in vertebrates. However, it remains unclear how respiratory surfaces and associated diffusion rates vary with body mass across vertebrates, particularly in relation to the body mass scaling of oxyg...

This experiment investigated the relationship between oxygen consumption and oxygen delivery (cardiac output X arterial oxygen content) in an acute canine model. Previous studies investigating this relationship have largely utilized methods in which oxygen consumption and oxygen delivery were each calculated using the same measured variables resulting in mathematical coupling of variables. In t...

A two-part experiment was designed to test the hypothesis that myocardial oxygen and carbon dioxide tensions, as measured by coronary venous oxygen and carbon dioxide tensions, determine coronary blood flow during increases in myocardial oxygen consumption. The left main coronary artery was pump-perfused at constant pressure in closed-chest, anesthetized dogs. Oxygenators in the perfusion circu...