Journal of Applied Physiology (J APPL PHYSIOL)

Publisher: American Physiological Society (1887- ), American Physiological Society

Journal description

The Journal of Applied Physiology publishes original papers that deal with diverse areas of research in applied physiology, especially those emphasizing adaptive and integrative mechanisms. Adaptive physiology includes 1) inherent adaptations such as those related to development, aging, and pathophysiological conditions and 2) adaptations to the external environment such as those occurring with exercise, microgravity, hypoxia, hypo- and hyperbaria, and hypo- and hyperthermic conditions. Integrative physiology includes 1) horizontal integration across organ systems and 2) vertical integration from molecule to cell to organ. In all areas of applied physiology, the use of cutting-edge techniques including molecular and cellular biology is strongly encouraged.

Current impact factor: 3.06

Impact Factor Rankings

2016 Impact Factor Available summer 2017
2014 / 2015 Impact Factor 3.056
2013 Impact Factor 3.434
2012 Impact Factor 3.484
2011 Impact Factor 3.753
2010 Impact Factor 4.232
2009 Impact Factor 3.732
2008 Impact Factor 3.658
2007 Impact Factor 3.632
2006 Impact Factor 3.178
2005 Impact Factor 3.037
2004 Impact Factor 2.824
2003 Impact Factor 3.027
2002 Impact Factor 2.72
2001 Impact Factor 2.581
2000 Impact Factor 2.297
1999 Impact Factor 2.081
1998 Impact Factor 2.122
1997 Impact Factor 1.77
1996 Impact Factor 2.05
1995 Impact Factor 1.947
1994 Impact Factor 1.852
1993 Impact Factor 1.799
1992 Impact Factor 1.959

Impact factor over time

Impact factor
Year

Additional details

5-year impact 3.77
Cited half-life >10.0
Immediacy index 0.69
Eigenfactor 0.04
Article influence 1.15
Website Journal of Applied Physiology website
Other titles Journal of applied physiology (Bethesda, Md.: 1985), Journal of applied physiology
ISSN 8750-7587
OCLC 11603017
Material type Periodical, Internet resource
Document type Journal / Magazine / Newspaper, Internet Resource

Publisher details

American Physiological Society

  • Pre-print
    • Author can archive a pre-print version
  • Post-print
    • Author cannot archive a post-print version
  • Conditions
    • Author's Pre-print on pre-print servers
    • NIH, Wellcome Trust, HHMI, MRC and BBSRC authors will on their behalf have the Publisher's version/PDF deposited in PubMed Central for release 12 months after publication
    • Publisher's version/PDF cannot be used
    • May link to publisher version with DOI
    • Publisher last reviewed on 03/06/2015
  • Classification
    yellow

Publications in this journal

  • [Show abstract] [Hide abstract]
    ABSTRACT: Genetic deletion of brain serotonin (5-HT) neurons in mice leads to ventilatory deficits and increased neonatal mortality during development. However, it is unclear if the loss of the 5-HT neurons or the loss of the neurochemical 5-HT led to the observed physiologic deficits. Herein, we generated a mutant rat model with constitutive CNS 5-HT depletion by mutation of the tryptophan hydroxylase 2 (Tph2) gene in Dark Agouti (DA(Tph2-/-)) rats. DA(Tph2-/-) rats lacked TPH immunoreactivity and brain 5-HT, but retain dopa decarboxylase-expressing raphe neurons. Mutant rats were also smaller, had relatively high mortality (~50%), and compared to controls had reduced room air ventilation and body temperatures at specific postnatal ages. In adult rats, breathing at rest and hypoxic and hypercapnic chemoreflexes were unaltered in adult male and female DA(Tph2-/-) rats. Body temperature was also maintained in adult DA(Tph2-/-) rats exposed to 4°C, indicating unaltered ventilatory and/or thermoregulatory control mechanisms. Finally, DA(Tph2-/-) rats treated with the 5-HT precursor 5-hydroxytryptophan (5-HTP) partially restored CNS 5-HT, and showed increased ventilation (P<0.05) at a developmental age when it was otherwise attenuated in the mutants. We conclude that constitutive CNS production of 5-HT is critically important to fundamental homeostatic control systems for breathing and temperature during postnatal development in the rat.
    No preview · Article · Feb 2016 · Journal of Applied Physiology
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    ABSTRACT: Although disorders of mineral metabolism and skeletal muscle are common in chronic kidney disease (CKD), their potential relationship remains unexplored. Elevations in plasma phosphate, parathyroid hormone and fibroblastic growth factor 23 together with decreased calcitriol levels are common features of CKD. High phosphate intake is a major contributor to progression of CKD. This study was primarily aimed to determine the influence of high phosphate intake on muscle and to investigate whether calcitriol supplementation counteracts negative skeletal muscle changes associated with long-term uremia. Proportions, and metabolic and morphological features of myosin-based muscle fiber-types were assessed in the slow-twitch soleus and the fast-twitch tibialis cranialis muscles of uremic rats (5/6 nephrectomy, Nx) and compared with sham-operated (So) controls. Three groups of Nx rats received either a standard diet (0.6% phosphorus, Nx-Sd), or a high-phosphorus diet (0.9% phosphorus, Nx-Pho), or a high-phosphorus diet plus calcitriol (10 ng/kg 3 d/wk ip, Nx-Pho+Cal) for 12 wk. Two groups of So rats received either a standard diet or a high-phosphorus diet (So-Pho) over the same period. A multivariate analysis encompassing all fiber-type characteristics indicated that Nx-Pho+Cal rats displayed skeletal muscle phenotypes intermediate between Nx-Pho and So-Pho rats, and that uremia-induced skeletal muscle changes were of greater magnitude in Nx-Pho than in Nx-Sd rats. In uremic rats, treatment with calcitriol preserved fiber-type composition, cross-sectional size, myonuclear domain size, oxidative capacity and capillarity of muscle fibers. These data demonstrate that high phosphorus diet potentiates and low dose calcitriol attenuates adverse skeletal muscle changes in long-term uremic rats.
    No preview · Article · Feb 2016 · Journal of Applied Physiology
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    ABSTRACT: In this Highlighted Topic we present five reviews that explore the molecular mechanisms mediating adaptive and maladaptive responses to exercise and environmental heat stress. Energetic stress, including changes in metabolic status, production of reactive oxygen species and increased temperature can all present significant challenges to cellular homeostasis that evoke cytoprotective mechanisms. Transcriptional changes form the basis of many adaptations with recent evidence suggesting epigenetics improves tolerance to a multitude of dissimilar stressors.
    No preview · Article · Feb 2016 · Journal of Applied Physiology
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    ABSTRACT: Results: Compared to 14 healthy subjects with similar anthropometrics, 23 patients with hyperventilation were characterized by increased variability of resting tidal ventilation (CV of VT median [interquartile]: 26 % [19 - 35] versus 36 % [28 - 48], p=0.020; slope: -6.63 [-7.65; -5.36] versus -3.88 [-5.91; -2.66], p=0.004) that was not related to increased chemical drive (loop gain: 0.051 [0.039 - 0.221] versus 0.044 [0.012 - 0.087], p=0.149) but that was related to an increased ventilatory complexity (Kappa values, p<0.05). Plant gain was decreased in patients and correlated with complexity (with Kappa 5 - degree 5: Rho= -0.48, p=0.006). In conclusion, well-defined patients suffering from hyperventilation disorder are characterized by increased variability of their resting ventilation due to increased ventilatory complexity with stable ventilatory-chemoresponsiveness interactions.
    No preview · Article · Feb 2016 · Journal of Applied Physiology
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    ABSTRACT: Not required for Viewpoint paper.
    No preview · Article · Feb 2016 · Journal of Applied Physiology
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    ABSTRACT: The intrinsic activating factors that induce transcription of HSP72 in skeletal muscle following exercise remain unclear. We hypothesized that the cytosolic Ca(2+) transient that occurs with depolarization is a determinant. We utilized intact, single skeletal muscle fibers from Xenopus laevis to test the role of the cytosolic Ca(2+) transient and several other exercise-related factors (fatigue, hypoxia, AMP-kinase, and cross-bridge cycling) on the activation of HSP72 transcription. HSP72 and HSP60 mRNA levels were assessed with real time quantitative PCR; cytosolic [Ca(2+)] ([Ca(2+)]cyt) was assessed with fura-2. Both fatiguing and non-fatiguing contractions resulted in a significant increase in HSP72 mRNA. As expected, peak [Ca(2+)]cyt remained tightly coupled with peak developed tension in contracting fibers. Pre-treatment with N-benzyl-p-toluene sulfonamide (BTS) resulted in depressed peak developed tension with stimulation, while peak [Ca(2+)]cyt remained largely unchanged from control values. Despite excitation-contraction uncoupling, BTS-treated fibers displayed a significant increase in HSP72 mRNA. Treatment of fibers with hypoxia (PO2 <3 mm Hg) or AMP-kinase activation had no effect on HSP72 mRNA levels. These results suggest that the intermittent cytosolic Ca(2+) transient that occurs with skeletal muscle depolarization provides a sufficient activating stimulus for HSP72 transcription. Metabolic or mechanical factors associated with fatigue development and cross-bridge cycling likely play a more limited role.
    No preview · Article · Feb 2016 · Journal of Applied Physiology
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    ABSTRACT: This article briefly reviews the fidelity of ground-based methods used to simulate human existence in weightlessness (spaceflight). These methods include horizontal bed rest (BR), head-down tilt bed rest (HDT), head-out water immersion (WI), and head-out dry immersion (DI; immersion with an impermeable elastic cloth barrier between subject and water). Among these, HDT has become by far the most commonly used method, especially for longer studies. DI is less common but well-accepted for long-duration studies. Very few studies exist that attempt to validate a specific simulation mode against actual microgravity. Many fundamental physical and thus physiological differences exist between microgravity and our methods to simulate it, and between the different methods. Also, although weightlessness is the salient feature of spaceflight, several ancillary factors of space travel complicate Earth-based simulation. In spite of these discrepancies and complications, the analogs duplicate many responses to 0 G reasonably well. As we learn more about responses to microgravity and spaceflight, investigators will continue to fine-tune simulation methods to optimize accuracy and applicability.
    No preview · Article · Feb 2016 · Journal of Applied Physiology
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    ABSTRACT: The rodent hindlimb unloading (HU) model was developed in the 1980's to make it possible to study possible mechanisms, responses and treatments for the adverse consequences of spaceflight. Decades before development of the HU model, weightlessness was predicted to yield deficits in the principal tissues responsible for structure and movement on Earth, primarily muscle and bone. Indeed, results from early spaceflight and HU experiments confirmed the expected sensitivity of the musculoskeletal system to gravity loading. Results from human and animal, spaceflight and HU experiments show that nearly all organ systems and tissues studied display some measurable changes, albeit sometimes minor and of uncertain relevance to astronaut health. The focus of this review is to examine key HU results for various, organ systems, including those related to stress, the immune, cardiovascular and nervous systems, vision changes and wound healing. Analysis of the HU model validity is important given its potential value for both hypothesis testing and countermeasure development.
    No preview · Article · Feb 2016 · Journal of Applied Physiology
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    ABSTRACT: Post cuff occlusion flow mediated dilation (FMD) is a proposed indicator of Nitric Oxide (NO)-bioavailability and vascular function. FMD is reduced in patients with sepsis and may be a marker of end organ damage and mortality. However, FMD likely does not solely reflect NO-mediated vasodilation, is technically challenging, and often demonstrates poor reproducibility. In contrast, passive leg movement (PLM), a novel methodology to assess vascular function, yields a hyperemic response that is predominately NO-dependent, reproducible, and easily measured. This study evaluated PLM as an approach to assess NO-mediated vascular function in patients with sepsis. We hypothesized that PLM induced hyperemia, quantified by the increase in leg blood flow (LBF), would be attenuated in sepsis. In a cross sectional study, seventeen subjects in severe sepsis or septic shock were compared with sixteen matched healthy controls. Doppler ultrasound was used to assess brachial artery FMD, and the hyperemic response to PLM in the femoral artery. FMD was attenuated in septic compared to control subjects (1.1±1.7% vs 6.8±1.3%). In terms of PLM, baseline LBF (196±33 ml/min vs 328±20 ml/min), peak change in LBF from baseline (133±28 ml/min vs 483±86 ml/min), and the LBF area under the curve (16±8.3 vs 143±33), were all significantly attenuated in septic subjects. Vascular function, as assessed by both FMD and PLM is attenuated in septic subjects compared to controls. These data support the concept that NO-bioavailability is attenuated in septic subjects, and PLM appears to be a novel and feasible approach to assess NO-mediated vascular function in sepsis.
    No preview · Article · Feb 2016 · Journal of Applied Physiology
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    ABSTRACT: The invention of the Phosphorescence Quenching Method for the measurement of oxygen concentration in blood and tissue revolutionized physiological studies of oxygen transport in living organisms. Since the pioneering publication by Vanderkooi and Wilson in 1987, many researchers have contributed to the measurement of oxygen in the microcirculation, oxygen imaging in tissues and microvessels and to the development of new extracellular and intracellular phosphorescent probes. However, there is a problem of congruency in data from different laboratories, because of inter-laboratory variability of the calibration coefficients in the Stern -Volmer equation. Published calibrations for a common oxygen probe Pd-porphyrin + BSA vary due differences in the used techniques. These methods are used for the formation of oxygen standards: chemical titration, calibrated gas mixtures and an oxygen electrode. Each method in turn also needs calibration. We have designed a barometric method for the calibration of oxygen probes by using a regulated vacuum to set multiple PO2 standards. The method is fast, accurate and can be applied to biological fluids obtained during or after an experiment. Calibration over the full physiological PO2 range (1-120 mmHg) takes about 15 min and requires 1-2 mg of probe.
    No preview · Article · Feb 2016 · Journal of Applied Physiology
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    ABSTRACT: Landing from a jump implies proper positioning of the lower limb segments and the generation of an adequate muscular force to cope with the imminent collision with the ground. This study assesses how a hypogravitational environment affects the control of landing after a counter-movement jump (CMJ). Eight participants performed submaximal CMJs on Earth (1 g-condition) and in a weightlessness environment with simulated gravity conditions generated by a pull-down force (1-, 0.6-, 0.4- and 0.2 g0-conditions). External forces applied to the body, movements of the lower limb segments and muscular activity of 6 lower limb muscles were recorded. (1) All subjects were able to jump and stabilize their landing in all experimental conditions, except one subject in 0.2 g0-condition. (2) The mechanical behavior of lower limb muscles switches during landing from a stiff spring to a compliant spring associated with a damper. This is true whatever the environment, on Earth as well as in environments where sensory inputs are altered. (3) The motor control of landing in simulated 1g0 reveals an increased 'safety margin' strategy, illustrated by increased stiffness and damping coefficient as compared to landing on Earth. (4) The motor command is adjusted to the task constraints: muscular activity of lower limb extensors and flexors, stiffness and damping coefficient decrease according to the decreased gravity level. Our results show that even if in daily living gravity can be perceived as a constant factor, subjects can cope with altered sensory signals, taking advantage of the remaining information (visual and/or decreased proprioceptive inputs).
    No preview · Article · Feb 2016 · Journal of Applied Physiology
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    ABSTRACT: We hypothesized that heat stress would decrease the anterior and posterior cerebral blood flow (CBF) during exercise, and the reduction in anterior CBF would be partly associated with large increase in extracranial BF. Nine subjects performed 40-min semi-recumbent cycling at 60% of the peak oxygen uptake in hot (35°C; Heat) and thermoneutral environments (25°C; Control). We evaluated the BF and conductance (COND) in the external carotid artery (ECA), internal carotid artery (ICA), and vertebral artery (VA) using ultrasonography. During Heat, the ICA and VA BF significantly increased 10 min after the start of exercise (P < 0.05) and thereafter gradually decreased. The ICA COND significantly decreased (P < 0.05), while VA COND unchanged throughout Heat. Compared with Control, the ICA and VA BF or COND at the end of Heat tended to be lower, but not significant. In contrast, ECA BF and COND at the end of Heat was higher compared with Control (P < 0.01). During Heat, a reduction in ICA BF appears to be associated with a decline in end-tidal CO2 tension (r = 0.84), while VA BF was affected by change in cardiac output (r = 0.87). In addition, change in ECA BF during Heat was negatively correlated with change in the ICA BF (r = -0.75). Heat stress modified the vascular response of head and brain arteries to exercise, which resulted in the alteration in the distribution of cardiac output. Moreover, hyperthermia-induced increase in extracranial BF might compromise anterior CBF during exercise with heat stress.
    No preview · Article · Feb 2016 · Journal of Applied Physiology
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    ABSTRACT: The purpose of this study was to determine the adjustments in the level of coactivation during a steadiness task performed by young and old adults after the torque-generating capacity of the antagonist muscles was reduced by a fatiguing contraction. Torque steadiness (coefficient of variation) and electromyographic (EMG) activity of the extensor and flexor carpi radialis muscles were measured as participants matched a wrist extensor target torque (10% maximum) before and after sustaining an isometric contraction (30% maximum) with wrist flexors to task failure. Time to failure was similar (P = 0.631) for young (417 ± 121 s) and old (452 ± 174 s) adults. The reduction in maximal voluntary contraction (MVC) torque (% initial) for the wrist flexors after the fatiguing contraction was greater (P = 0.006) for young (32.5 ± 13.7%) than old (21.8 ± 6.6%) adults. Moreover, MVC torque for the wrist extensors declined for old (-13.7 ± 12.7%; P = 0.030), but not young (-5.4 ± 13.8%; P = 0.167) adults. Torque steadiness during the matching task with the wrist extensors was similar before and after the fatiguing contraction for both groups, but the level of coactivation increased after the fatiguing contraction for old (P = 0.049) but not young (P = 0.137) adults, and was twice the amplitude for old adults (P = 0.002). These data reveal that old adults are able to adjust the amount of antagonist muscle activity independent of the agonist muscle during steady submaximal contractions.
    No preview · Article · Feb 2016 · Journal of Applied Physiology
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    ABSTRACT: Cardiac alternans has been associated with the incidence of ventricular tachyarrhythmias and sudden cardiac death. The aim of this study was to investigate the effect of impaired mitochondrial function in the genesis of cellular alternans and to examine whether modulating the sarcoplasmic reticulum (SR) Ca(2+) ameliorates the level of alternans. Cardiomyocytes isolated from control and doxycyline induced SERCA2a upregulated mice were loaded with two different Ca(2+) indicators to selectively measure mitochondrial and cytosolic Ca(2+) using a custom-made fluorescence photometry system. The degree of alternans was defined as the alternans ratio AR (1- [small Ca(2+) intensity])/[large Ca(2+) intensity]). Blocking of complex I and II, cytochrome c oxidase, F0F1- synthase, α-ketoglutarate dehydrogenase of the electron transport chain, increased alternans in both control and SERCA2a mice (p<0.01) Changes in AR in SERCA2a upregulated mice were significantly less pronounced than those observed in control in 7 of 9 tested conditions (p<0.04). N-Acetyl-L-cysteine (NAC), rescued alternans in myocytes that were previously exposed to an oxidizing agent (p<0.001). CGP, an antagonist of the mitochondrial Na(+)-Ca(2+) exchanger had the most severe effect on AR. Exposure to cyclosporin A, a blocker of the mitochondrial permeability transition pore reduced CGP induced alternans (p<0.0001). The major findings of this study are that impairment of mitochondrial Ca(2+) cycling and energy production leads to a higher amplitude of alternans in both control and SERCA2a upregulated mice but changes in SERCA2a upregulated mice are less severe, indicating that SERCA2a mice are more capable to sustain electrical stability during stress. This suggests a relationship between sarcoplasmic Ca(2+) content and mitochondrial dysfunction during alternans which may potentially help to understand changes in Ca(2+) signaling in myocytes from diseased hearts, leading to new therapeutic targets.
    No preview · Article · Feb 2016 · Journal of Applied Physiology
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    ABSTRACT: Human psychology and physiology are significantly altered by isolation and confinement. In light of planned exploration class interplanetary missions, the related adverse effects on the human body need to be explored and defined as they have a large impact on a mission's success. Terrestrial space analogues offer an excellent controlled environment to study some of these stressors during a space mission in isolation without the complex environment of the International Space Station. Participants subjected to these space analogue conditions can encounter typical symptoms ranging from neurocognitive changes, fatigue, misaligned circadian rhythm, sleep disorders, altered stress hormone levels and immune modulatory changes. This review focuses on both the psychological and the physiological responses observed in participants of long-duration space-flight analogue studies, such as Mars500 or Antarctic winter-over. They provide important insight into similarities and differences encountered in each simulated setting. The identification of adverse effects from confinement allows not only the crew to better prepare for, but also to design feasible countermeasures that will help support space travelers during exploration class missions in the future.
    No preview · Article · Feb 2016 · Journal of Applied Physiology
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    ABSTRACT: Brown adipose tissue (BAT) activation increases glucose and lipid consumption; as such, it is been considered as a potential therapy to decrease obesity. BAT is highly vascularized and its activation is associated with a necessary increase in blood flow. However, whether increasing BAT blood flow per se increases BAT activity is unknown. To examine this hypothesis, we investigated whether an isolated increase in BAT blood flow obtained by beta-2 adrenoreceptor (β2-AR) stimulation with salbutamol increased BAT activity. Brown adipose tissue blood flow was estimated in vivo in mice using contrast-enhanced ultrasound. The absence of direct effect of salbutamol on the function of isolated brown adipocytes was assessed by measuring oxygen consumption. The effect of salbutamol on BAT activity was investigated by measuring BAT glucose uptake in vivo. Brown adipose tissue blood flow increased by 2.3 ± 0.6 fold during β2-AR stimulation using salbutamol infusion in mice (P=0.003). β2-AR gene expression was detectable in BAT but was extremely low in isolated brown adipocytes. Oxygen consumption of isolated brown adipocytes did not change with salbutamol exposure, confirming the absence of a direct effect of β2-AR agonist on brown adipocytes. Finally, β2-AR stimulation by salbutamol increased BAT glucose uptake in vivo (991±358 vs. 135±49 ng glucose/mg tissue/45 min in salbutamol vs. saline injected mice respectively, P=0.046). In conclusion, an increase in BAT blood flow without direct stimulation of the brown adipocytes is associated with increased BAT metabolic activity. Increasing BAT blood flow might represent a new therapeutic target in obesity.
    No preview · Article · Jan 2016 · Journal of Applied Physiology