The effect of aging and cardiorespiratory fitness on the lung diffusing capacity response to exercise in healthy humans
In conclusion, these data suggest that despite the age-associated deterioration in the structure and function of the pulmonary circulation, expansion of the pulmonary capillary network does not become limited during exercise in healthy individuals regardless of age or cardiorespiratory fitness level.
NEW & NOTEWORTHY Healthy aging is a crucial area of research. This article details how differences in age and cardiorespiratory fitness level affect lung diffusing capacity, particularly during high-intensity exercise. We conclude that highly fit older adults do not experience a limit in lung diffusing capacity during high...
Source: Journal of Applied Physiology - June 5, 2017 Category: Physiology Authors: Coffman, K. E., Carlson, A. R., Miller, A. D., Johnson, B. D., Taylor, B. J. Tags: RESEARCH ARTICLE Source Type: research
Acute impact of conventional and eccentric cycling on platelet and vascular function in patients with chronic heart failure
Evidence-based guidelines recommend exercise therapy for patients with chronic heart failure (CHF). Such patients have increased atherothrombotic risk. Exercise can transiently increase platelet activation and reactivity and decrease vascular function in healthy participants, although data in CHF are scant. Eccentric (ECC) cycling is a novel exercise modality that may be particularly suited to patients with CHF, but the acute impacts of ECC cycling on platelet and vascular function are currently unknown. Our null hypothesis was that ECC and concentric (CON) cycling, performed at matched external workloads, would not induce...
Source: Journal of Applied Physiology - June 5, 2017 Category: Physiology Authors: Haynes, A., Linden, M. D., Chasland, L. C., Nosaka, K., Maiorana, A., Dawson, E. A., Dembo, L. H., Naylor, L. H., Green, D. J. Tags: RESEARCH ARTICLE Source Type: research
Effects of dobutamine on intestinal microvascular blood flow heterogeneity and O2 extraction during septic shock
In conclusion, dynamic changes in microvascular blood flow heterogeneity at jejunal mucosa are closely related to the mesenteric O2 extraction ratio, suggesting a crucial role for microvascular blood flow distribution on O2 uptake during development and resuscitation from septic shock.
NEW & NOTEWORTHY Our observations suggest that dynamic changes in the heterogeneity of microvascular blood flow at the gut mucosa are closely related to mesenteric O2 extraction, thus supporting the role of decreasing functional capillary density and increased intercapillary distances on alterations of O2 uptake during development and re...
Source: Journal of Applied Physiology - June 5, 2017 Category: Physiology Authors: Ospina-Tascon, G. A., Garcia Marin, A. F., Echeverri, G. J., Bermudez, W. F., Madrinan-Navia, H., Valencia, J. D., Quinones, E., Rodriguez, F., Marulanda, A., Arango-Davila, C. A., Bruhn, A., Hernandez, G., De Backer, D. Tags: RESEARCH ARTICLE Source Type: research
An international collaboration studying the physiological and anatomical cerebral effects of carbon dioxide during head-down tilt bed rest: the SPACECOT study
Exposure to the microgravity environment results in various adaptive and maladaptive physiological changes in the human body, with notable ophthalmic abnormalities developing during 6-mo missions on the International Space Station (ISS). These findings have led to the hypothesis that the loss of gravity induces a cephalad fluid shift, decreased cerebral venous outflow, and increased intracranial pressure, which may be further exacerbated by increased ambient carbon dioxide (CO2) levels on the ISS. Here we describe the SPACECOT study (studying the physiological and anatomical cerebral effects of CO2 during head-down tilt), ...
Source: Journal of Applied Physiology - June 1, 2017 Category: Physiology Authors: Marshall-Goebel, K., Mulder, E., Donoviel, D., Strangman, G., Suarez, J. I., Venkatasubba Rao, C., Frings-Meuthen, P., Limper, U., Rittweger, J., Bershad, E. M., the SPACECOT Investigators Group Tags: RESEARCH ARTICLE Source Type: research
Neuropeptide Y3-36 incorporated into PVAX nanoparticle improves functional blood flow in a murine model of hind limb ischemia
In conclusion, we were able to show that PVAX-NPY3–36 can induce angiogenesis and arteriogenesis as well as improve functional blood flow in a murine model of hind limb ischemia.
NEW & NOTEWORTHY Our research project proposes a novel method for drug delivery. Our patented PVAX nanoparticle can detect areas of ischemia and oxidative stress. Although there have been studies about delivering angiogenic molecules to areas of ischemic injury, there are drawbacks of nonspecific delivery as well as short half-lives. Our study is unique because it can specifically deliver NPY3–36 to ischemic tissue and appears to e...
Source: Journal of Applied Physiology - June 1, 2017 Category: Physiology Authors: Eshun, D., Saraf, R., Bae, S., Jeganathan, J., Mahmood, F., Dilmen, S., Ke, Q., Lee, D., Kang, P. M., Matyal, R. Tags: RESEARCH ARTICLE Source Type: research
Ventilation heterogeneity measured by multiple breath inert gas testing is not affected by inspired oxygen concentration in healthy humans
Multiple breath washout (MBW) and oxygen-enhanced MRI techniques use acute exposure to 100% oxygen to measure ventilation heterogeneity. Implicit is the assumption that breathing 100% oxygen does not induce changes in ventilation heterogeneity; however, this is untested. We hypothesized that ventilation heterogeneity decreases with increasing inspired oxygen concentration in healthy subjects. We performed MBW in 8 healthy subjects (4 women, 4 men; age = 43 ± 15 yr) with normal pulmonary function (FEV1 = 98 ± 6% predicted) using 10% argon as a tracer gas and oxygen concentrations of 12.5%, 21%, or 90%. MBW was...
Source: Journal of Applied Physiology - June 1, 2017 Category: Physiology Authors: Hopkins, S. R., Elliott, A. R., Prisk, G. K., Darquenne, C. Tags: RESEARCH ARTICLE Source Type: research
Impact of positive pressure ventilation on mean systemic filling pressure in critically ill patients after death
This study is the first report of a tidal ventilation- and positive end-expiratory pressure-related increase in Pms in critically ill patients. The results challenge the utility and the value estimating Pms in heart-beating patients by reconstruction of the venous return curve using varying inflation pressures. (Source: Journal of Applied Physiology)
Source: Journal of Applied Physiology - June 1, 2017 Category: Physiology Authors: Repesse, X., Charron, C., Geri, G., Aubry, A., Paternot, A., Maizel, J., Slama, M., Vieillard-Baron, A. Tags: RESEARCH ARTICLE Source Type: research
Reply to Drs. Van Breda et al.
(Source: Journal of Applied Physiology)
Source: Journal of Applied Physiology - May 18, 2017 Category: Physiology Authors: Poole, D. C., Jones, A. M. Tags: LETTERS TO THE EDITOR Source Type: research
Clinical VO2peak is "part of the deal"
(Source: Journal of Applied Physiology)
Source: Journal of Applied Physiology - May 18, 2017 Category: Physiology Authors: van Breda, E., Schoffelen, P. F. M., Plasqui, G. Tags: LETTERS TO THE EDITOR Source Type: research
Moderate and intense muscular exercises induce marked intramyocellular metabolic acidosis in sickle cell disease mice
This study has identified for the first time an exacerbated exercise-induced intramuscular acidosis in SCD mice.
NEW & NOTEWORTHY The main finding of the present study was that the exercise-induced intramuscular acidosis was systematically more pronounced in sickle cell disease (SCD) mice as compared with their control counterparts. This result is important since it has been demonstrated in vitro that acidosis can trigger hemoglobin polymerization. From that point of view, our results tend to support the idea that high-intensity exercise may increase the risk of hemoglobin polymerization in SCD. (Source: Journal of Applied Physiology)
Source: Journal of Applied Physiology - May 18, 2017 Category: Physiology Authors: Chatel, B., Messonnier, L. A., Hourde, C., Vilmen, C., Bernard, M., Bendahan, D. Tags: RESEARCH ARTICLE Source Type: research
Oral N-acetylcysteine and exercise tolerance in mild chronic obstructive pulmonary disease
In conclusion, modulation of plasma redox status with oral NAC treatment was not translated into beneficial effects on central or peripheral components of the oxygen transport pathway, thereby failing to improve exercise tolerance in nonhypoxemic patients with mild COPD.
NEW & NOTEWORTHY Acute antioxidant treatment with N-acetylcysteine (NAC) elevated plasma glutathione but did not modulate central or peripheral components of the O2 transport pathway, thereby failing to improve exercise tolerance in patients with mild chronic obstructive pulmonary disease (COPD). (Source: Journal of Applied Physiology)
Source: Journal of Applied Physiology - May 18, 2017 Category: Physiology Authors: Hirai, D. M., Jones, J. H., Zelt, J. T., da Silva, M. L., Bentley, R. F., Edgett, B. A., Gurd, B. J., Tschakovsky, M. E., ODonnell, D. E., Neder, J. A. Tags: RESEARCH ARTICLE Source Type: research
Muscle-specific and age-related changes in protein synthesis and protein degradation in response to hindlimb unloading in rats
In this study, we showed that age did not intensify the atrophy response to unloading in rats, but rather that the degree of atrophy was highly variable across muscles, indicating that changes in protein synthesis and protein degradation occur in a muscle-specific manner. Our data emphasize the importance of studying muscles of varying fiber-type and physiological function at multiple time points to fully understand the molecular mechanisms responsible for disuse atrophy. (Source: Journal of Applied Physiology)
Source: Journal of Applied Physiology - May 18, 2017 Category: Physiology Authors: Baehr, L. M., West, D. W. D., Marshall, A. G., Marcotte, G. R., Baar, K., Bodine, S. C. Tags: RESEARCH ARTICLE Source Type: research
Exercise-induced dehydration alters pulmonary function but does not modify airway responsiveness to dry air in athletes with mild asthma
This study is the first to investigate the effect of whole body dehydration on airway responsiveness. Our data suggest that the airway response to dry air hyperpnea in athletes with mild asthma and/or exercise-induced bronchoconstriction is not exacerbated in a state of mild dehydration. On the basis of alterations in lung volumes, however, exercise-induced dehydration appears to compromise small airway function. (Source: Journal of Applied Physiology)
Source: Journal of Applied Physiology - May 18, 2017 Category: Physiology Authors: Simpson, A. J., Romer, L. M., Kippelen, P. Tags: RESEARCH ARTICLE Source Type: research
Combined long-term caffeine intake and exercise inhibits the development of diabetic nephropathy in OLETF rats
This study was performed to examine the effects of long-term caffeine-intake, with and without exercise, on the progression of diabetic nephropathy (DN) in an obese diabetic rat model. Thirty-two male Otsuka Long-Evans Tokushima fatty (OLETF) rats were assigned to sedentary (OLETF-Sed), exercise (OLETF-Ex), caffeine-intake (OLETF-Caf), and combined (OLETF-Caf + Ex) groups. Caffeine-intake groups were fed rat chow containing caffeine (90.7 ± 4.7 mg/kg/day). The OLETF-Ex and OLETF-Caf + Ex groups were able to run voluntarily at any time using a rotatory wheel. Body weight (BW) and blood pressure (BP) were measured wee...
Source: Journal of Applied Physiology - May 18, 2017 Category: Physiology Authors: Suzuki, M., Shindo, D., Suzuki, R., Shirataki, Y., Waki, H. Tags: RESEARCH ARTICLE Source Type: research
Equations for O2 and CO2 solubilities in saline and plasma: combining temperature and density dependences
Solubilities of respiratory gasses in water, saline, and plasma decrease with rising temperatures and solute concentrations. Henry’s Law, C = α·P, states that the equilibrium concentration of a dissolved gas is solubility times partial pressure. Solubilities in the water of a solution depend on temperature and the content of other solutes. Blood temperatures may differ more than 20°C between skin and heart, and an erythrocyte will undergo that range as blood circulates. The concentrations of O2 and CO2 are the driving forces for diffusion, exchanges, and for reactions. We provide an equation for O2 a...
Source: Journal of Applied Physiology - May 18, 2017 Category: Physiology Authors: Christmas, K. M., Bassingthwaighte, J. B. Tags: INNOVATIVE METHODOLOGY Source Type: research
