OBJECTIVE To determine which physiological variables conduce to walking intolerance in patients with peripheral arterial disease (PAD). DESIGN The physiological response to a graded treadmill exercise test (GTT) in patients with PAD was characterised. SETTING Patients were recruited from the Department of Vascular Surgery, Groote Schuur Hospital, Cape Town. SUBJECTS Thirty-one patients di...

The present study investigated whether muscular monocarboxylate transporter (MCT) 1 and 4 contents are related to the blood lactate removal after supramaximal exercise, fatigue indexes measured during different supramaximal exercises, and muscle oxidative parameters in 15 humans with different training status. Lactate recovery curves were obtained after a 1-min all-out exercise. A biexponential...

Thermal limits in ectotherms may arise through a mismatch between supply and demand of oxygen. At higher temperatures, the ability of their cardiac and ventilatory activities to supply oxygen becomes insufficient to meet their elevated oxygen demand. Consequently, higher levels of oxygen in the environment are predicted to enhance tolerance of heat, whereas reductions in oxygen are expected to ...

Chronic exposure to a stressor elicits adaptations enhancing the tolerance to that stressor. These adaptive responses might also improve tolerance under less stressful conditions. For example, historically there has been much interest in the adaptive responses to high-altitude, or hypoxia, and their ergogenic potential under sea-level, or normoxic, conditions. In contrast, the influence of the ...

This study examined the physiological effect of reduced plasma cortisol (C) during prolonged exercise in humans. The effects of normal C (NC) were compared with metyrapone-induced low C (LC) on plasma substrate availability and the respiratory exchange ratio during 2 h of exercise at approximately 60% peak O2 consumption in nine subjects. The C responses were compared with preexercise (Pre) lev...

Blood lactate concentrations reflect the balance between lactate production and clearance. During glycolysis in resting state, most glucose is converted to pyruvate. Pyruvate is metabolized through the aerobic pathway, to acetyl-CoA by pyruvate dehydrogenase (PDH) to enter the tricarboxylic acid cycle that is the main source of energy for cellular metabolism. In times of stress, tissue oxygen (...

The purpose of this study was to (a) assess the usefulness of volume load (VL), session rate of perceived exertion (SRPE), RPE load (RPEL), and a modified RPEL (RPEL-2) to estimate internal load from resistance exercise (RE) and (b) further assess the interactions between SRPE, VL, and RE intensity. Twelve healthy men (25 ± 4 years) completed RE sessions at 55, 70, and 85 1 repetition maximum (...

background: long surgery causes hypothermia and increased bleeding and can increase the arterial blood lactate levels during anesthesia. it causes cellular hypoxia and its complications. considering the core temperature of the patient during surgery it can prevent hypoxia. this study aimed to compare the effects of different temperatures on the core temperature and the concentrations of lactate...

UNLABELLED Lactate is a key myocardial energy source. Lactate metabolism is altered in a variety of conditions, such as exercise and diabetes mellitus. However, to our knowledge, noninvasive quantitative measurements of myocardial lactate metabolism have never been performed because of the lack of an adequate radiotracer. In this study we tested L-3-(11)C-lactate ((11)C-lactate) as such a trace...

BACKGROUND AND PURPOSE Oxidative stress after ischemia/reperfusion has been shown to induce DNA damage and subsequent DNA repair activity. Ku 70/86, multifunctional DNA repair proteins, bind to broken DNA ends and trigger a DNA repair pathway. We investigated the involvement of these proteins in the development of neuronal tolerance to global cerebral ischemia after ischemic preconditioning. ...