Search results for "oxygen consumption"
showing 10 items of 347 documents
Mitochondrial respiration on rumenic and linoleic acids
2001
Rumenic acid ( cis -9, trans -11-C 18:2 ) represents approx. 80% of conjugated linoleic acid (CLA) in dairy products. CLA has been shown to exert beneficial effects on health, but little work has been devoted to the ability to oxidize CLA isomers and the role of these isomers in the modulation of β-oxidation flux. In the present study, respiration on rumenic acid was compared with that on linoleic acid ( cis -9, cis -12-C 18:2 ) with the use of rat liver mitochondria. In state-3, respiration was decreased by half with rumenic acid in comparison with linoleic acid. In the uncoupled state, respiration on CLA remained 30% lower. The lower ability to oxidize CLA was investigated through charact…
TNFα Primes Polymorphonuclear Leukocytes for an Enhanced Respiratory Burst to a Similar Extent As Bacterial Lipopolysaccharide
1990
We examined whether preincubating polymorphonuclear leukocytes (PMN) with TNF alpha would result in an enhanced respiratory burst upon subsequent stimulation by various agents. Bacterial lipopolysaccharide (LPS), a known primer of PMN, was used as control. We found that both LPS (0.01 to 10.0 microgram/ml) and recombinant TNF alpha (0.001 to 1.0 microgram/ml) act as direct stimulants of PMN as measured by chemiluminescence. Sixty minutes of preincubation of PMN with 1 microgram/ml TNF alpha or 10 micrograms/ml LPS resulted in similar priming for the respiratory burst elicited by opsonized zymosan, phorbol myristate acetate, zymosan, zymosan-activated serum, aggregated immunoglobulin, and f-…
Is there a linkage between metabolism and personality in small mammals? The root vole (Microtus oeconomus) example
2010
Significant inter-individual variation in the rate of animal metabolism is a widespread phenomenon that has started to accumulate general interest. Here we follow recent calls to focus on linkage between the variation in energy metabolism and animal personality. By using wild caught root voles as a study species, we examined the relationship between the behavioral patterns (assessed in open field test) and resting metabolic rate (RMR), both of which are known to show large individual differences and intra-individual consistency in voles. Our results showed only a weak relationship between personality traits and metabolism, since the most parsimonious model (according to AICc) explaining RMR…
Influence of PEEP on cerebral blood flow and cerebrovascular autoregulation in patients with acute respiratory distress syndrome.
2013
High levels of positive end-expiratory pressure (PEEP), as part of the treatment in patients with acute respiratory distress syndrome (ARDS), may prevent alveolar collapse and maintain oxygenation. PEEP potentially reduces cerebral venous return, increases intracranial blood volume, and may, therefore, affect cerebral blood flow (CBF) and cerebrovascular autoregulation (AR). This study investigates the effect of PEEP on CBF and AR in patients with respiratory failure.CBF velocity was measured using transcranial doppler and correlated with the invasive arterial blood pressure curve to calculate the index of AR Mx (Mx0.3 indicates impaired AR). Mx was measured at lower PEEP levels and after i…
Effects of resistance training frequency on cardiorespiratory fitness in older men and women during intervention and follow-up.
2017
This study investigated the effects of resistance training (RT) performed with different frequencies, including a follow-up period, on cardiorespiratory fitness in healthy older individuals. Eighty-eight men and women (69 ± 3 years, 167 ± 9 cm and 78 ± 14 kg) were randomly placed into four groups: training one- (M1 = 11, W1 = 12), two- (M2 = 7, W2 = 14), or three- (M3 = 11, W3 = 13) times-per-week or a non-training control group (MCon = 11, WCon = 9). During months 1–3, all subjects trained two-times-per-week while during the subsequent 6 months, training frequency was set according to the group. Oxygen consumption (cycling economy: CE), gross efficiency (GE), blood lactate concentrations (…
Effects of a one-year exercise training program in adults over 70 years old: a study with a control group
2007
Background and aims: Exercise training is known to improve exercise tolerance in elderly subjects. Therefore the present study aimed at investigating the effects of one year of combined endurance and resistance training in healthy older people. Methods: After baseline evaluation, subjects were assigned to either the training group (n=24, age 77.2±3.6) or the control group (n=16, age 76.1±4.8). Subjects in the control group did not change anything in their everyday activities, whereas subjects in the training group underwent moderately intensive combined exercise training, 3 hours a week over the course of one year. Breath-by-breath oxygen uptake and heart rate were measured at each workload…
Effects of Combined Strength and Endurance Training on Treadmill Load Carrying Walking Performance in Aging Men
2010
Holviala, J, Hakkinen, A, Karavirta, L, Nyman, K, Izquierdo, M, Gorostiaga, EM, Avela, J, Korhonen, J, Knuutila, V-P, Kraemer, WJ, and Hakkinen, K. Effects of combined strength and endurance training on treadmill load carrying walking performance in aging men. J Strength Cond Res 24(6): 1584-1595, 2010—The present study examined the effects of twice weekly total body strength training (ST), endurance cycling (ET), and combined ST and ET (2 + 2 times a week) (SET) training on the load carrying walking test performance on the treadmill (TM) and changes in neuromuscular and endurance performance during a 21-week training period in aging men. Forty healthy men (54.8 6 8.0 years) were divided in…
Heart Rate Dynamics after Combined Endurance and Strength Training in Older Men
2009
Purpose: Aging alters cardiac autonomic function, which may contribute to a higher risk of cardiac events. Spectral measures of HR variability (HRV) and fractal-like behavior of HR are considered as markers of a healthy heart. The present study examined the effects of combining endurance and strength training compared with endurance or strength training alone on HR dynamics and physical fitness in older previously untrained men aged 40-67 yr. Methods: Subjects were randomized into endurance training (E, n = 23), strength training (S, n = 25), combined endurance and strength training (ES, n = 29), or control group (C, n = 16). Short-term fractal scaling exponent ([alpha]1) and spectral HRV w…
Effect of Eight Weeks' Physical Training on Muscle and Connective Tissue of the M. Vastus Lateralis in 69-year-old Men and Women
1977
Five one-hour exercise periods a week for 8 weeks included walking-jogging, swimming, gymnastics and ballgames for 26 healthy male and female 69-year-old pensioners. The mean maximal oxygen uptake of the men increased from 28.9 ml-kg-1-min-1 before training to 32.0 ml-kg-1-min-1 after training and for the women from 27.9 to 31.3 ml-kg-1-min-1. Muscle malate dehydrogenase activity was increased while that for lactate dehydrogenase decreased or remained the same. The activity of these enzymes was higher in the male both before and after training when compared with the female. However, the percentage number of slow twitch muscle fibers was nearly the same in both groups. Prolyl hydroxylase act…
Reductive and oxidative metabolism of nitrofurantoin in rat liver.
1980
The elimination of nitrofurantoin was studied in the isolated rat liver using a recirculating hemoglobin-free perfusion system. The most rapid clearance of nitrofurantoin (0.1 mM) was found under hypoxia (8 ml/min) or anoxia (11 ml/min) indicating a fast and oxygen-sensitive reductive metabolism. The hepatic elimination of nitrofurantoin under anaerobic conditions apparently is not catalyzed by xanthine oxidase, aldehyde oxidase or cytochrome P-450 as judged from the lack of influence of the inhibitors (0.1 mM) allopurinol, menadione, metyrapone, α-naphthoflavone or of carbon monoxide (50%; v/v). Under aerobic conditions the hepatic clearance of nitrofurantoin is rather low (1 ml/min) indic…