Search results for "oxygen consumption"
showing 10 items of 347 documents
The specificity of prostaglandin E2 (PGE2) in reducing coronary vascular resistance: A comparison with adenosine.
1978
Experiments were performed on the isolated, electrically driven guinea-pig heart, perfused at constant rate. All animals were pretreated with reserpine. Myocardial contractile force (MCF), coronary perfusion pressure (CPP) and myocardial oxygen consumption (QO2) were monitored continuously. Both adenosine (ADO) and PGE2 produced a concentration-dependent decrease in the CPP. The ED50 (50% of maximum response) was 2.1 +/- 0.6 X 10(-9)M for PGE2 but 40 +/- 7 X 10(-9)M for ADO (P less than 0.01) at 1.8 mM Ca(e). This coronary vasodilation was independent of the external Ca-concentration, which was varied between 0.55-9.0 mM. PGE2 had no effect on MCF or QO2 and the effect of ADO was only sligh…
Experiences from a randomised, controlled trial on cycling to school: does cycling increase cardiorespiratory fitness?
2012
Aims: The objective of the present study was to investigate the effect of a 12-week randomised controlled cycling-to-school trial on cardiorespiratory fitness. Methods: A total of 53 10- to 13-year-old children from one public school were included. The children were randomised into either a cycling group or a control group. The cycling group was encouraged to cycle to and from school each day during a period of 12 weeks. Peak oxygen consumption (VO2peak) and anthropometrical data (weight and height) were measured at baseline and at the end of the 12-week period. Results: No significant differences were observed in VO2peak change over the 12-week period between the cycling group and the con…
Tumor Oxygenation in Anemic Rats: Effects of Erythropoietin Treatment Versus Red Blood Cell Transfusion
1995
Anemia was induced in rats by the development of a hemorrhagic ascites. These animals also bore solid tumors (DS-sarcomas) on the hind foot dorsum. The effects of two methods for anemia correction on oxygenation in the solid tumors were compared in this study. Anemia was corrected either chronically by erythropoietin administration (1000 IU/kg) over 14 days (EPO) or acutely by transfusion with red blood cells (TR). Non-anemic and untreated anemic animals served as controls. Tumor oxygenation was determined in anesthetized animals using polarographic needle electrodes and pO2 histography. The reduction in hematocrit and hemoglobin content found in anemic animals could successfully be correct…
Continuous monitoring of mixed venous oxygen saturation in infants after cardiac surgery
1989
Continuous mixed venous oxygen saturation (SvO2c) was measured in 16 infants immediately after cardiac surgery. A polyurethane 4F, dual channel catheter (Opticath, Modell U440, Oximetrix) with fiberoptic filaments was introduced into the pulmonary artery during cardiothoracic surgery. The catheters were left in place for an average of 67.5 h (range 27 h -125 h) and there were no catheter-related complications. Correlation between continuous in vivo SvO2 values and in vitro values was satisfactory (r = 0.85), whereas a correlation between SvO2c and arterial oxygen saturation (SaO2) was not found (r = 0.07). The sampled arterial lactate values were inversely correlated to the simultaneously m…
Exercise training improves peak oxygen consumption and haemodynamics in patients with severe pulmonary arterial hypertension and inoperable chronic t…
2015
Aims The impact of exercise training on the right heart and pulmonary circulation has not yet been invasively assessed in patients with pulmonary hypertension (PH) and right heart failure. This prospective randomized controlled study investigates the effects of exercise training on peak VO2/kg, haemodynamics, and further clinically relevant parameters in PH patients. Methods and results Eighty-seven patients with pulmonary arterial hypertension and inoperable chronic thrombo-embolic PH (54% female, 56 ± 15 years, 84% World Health Organization functional class III/IV, 53% combination therapy) on stable disease-targeted medication were randomly assigned to a control and training group. Medica…
Sports-related injuries in elderly men still active in sports.
1994
By means of a questionnaire with a complementary interview and physical examination, the site and nature of sports injuries were investigated over a 10-year period (1977-1987) in 97 elderly athletes (age range 70-81 years). The athletes were still active in training and competition with a mean competition background of 15 years. Of the subjects studied 30 were strength/power athletes and the remaining 67 endurance athletes. Altogether we found 273 sports-related injuries (169 acute and 104 overuse injuries). Of the injuries 75% had occurred in the lower extremities. The most commonly injured part of the body was the knee (20% of all cases). Sprains of the thigh and knee were the most freque…
Endurance training in patients with chronic obstructive pulmonary disease: a comparison of high versus moderate intensity.
2000
Abstract Gimenez M, Servera E, Vergara P, Bach JR, Polu J-M. Endurance training in patients with chronic obstructive pulmonary disease: a comparison of high versus moderate intensity. Arch Phys Med Rehabil 2000;81:102-9. Purpose: To create a maximum tolerated 45-minute aerobic training program for patients with chronic obstructive pulmonary disease (COPD) and to compare its outcomes with those of commonly prescribed moderate exercise. Design: Prospective, randomized trial. Setting: A work physiology laboratory. Patients and Methods: The maximum exercise intensities that 7 COPD patients could sustain for 45 minutes were determined on a bilevel exercise ergometer. The patients then exercised …
Maximal isometric strength indices are associated with the oxygen cost of walking and running in recreationally active men and women.
2021
This study assessed the associations of maximal isometric strength and movement economy in 126 recreationally active men and women. Oxygen consumption was assessed through a graded treadmill test with 4-minute increments (4-12 km∙h
Serum Sex Hormone–Binding Globulin and Cortisol Concentrations are Associated With Overreaching During Strenuous Military Training
2010
The purpose was (a) to study the effect of an 8-week Finnish military basic training period (BT) on physical fitness, body composition, mood state, and serum biochemical parameters among new conscripts; (b) to determine the incidence of overreaching (OR); and (c) to evaluate whether initial levels or training responses differ between OR and noOR subjects. Fifty-seven males (19.7 ± 0.3 years) were evaluated before and during BT. Overreaching subjects had to fulfill 3 of 5 criteria: decreased aerobic physical fitness (VO2max), increased rating of perceived exertion (RPE) in 45-minute submaximal test at 70% of VO2max or sick absence from these tests, increased somatic or emotional symptoms of …
The neuroprotective effect of lactate is not due to improved glutamate uptake after controlled cortical impact in rats.
2012
For many years lactate was considered to be a waste product of glycolysis. Data are accumulating that suggest that lactate is an important energy substrate for neurons during activation. In severe traumatic brain injury (TBI) glutamate release and ischemic cerebral blood flow (CBF) are major factors for a mismatch between energy demand and supply and for neuronal cell death. Although ATP and behavior could be improved by lactate treatment after TBI, no histological correlate nor any linkage to better astrocytic glutamate uptake or CBF as possible mechanisms have been described. We subjected male rats to a controlled cortical impact (CCI; 5 m/sec, 2.5 mm). To study the effects of lactate tre…