Impact of physical training on the ultrastructure of midthigh muscle in normal subjects and in patients treated with glucocorticoids.

Horber, Fritz F.; Hoopeler, H; Scheidegger, J. R.; Grünig, B.; Howald, H.; Frey, Felix J.

doi:10.1172/jci112935

Cited by 78 publications

(44 citation statements)

References 36 publications

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“…Whereas it is well established that glucocorticoids induce insulin resistance (2,6) and promote proteolysis (13), studies in the field of intermediary lipid metabolism have yielded more conflicting results.…”

mentioning

confidence: 99%

Effects of cortisol on lipolysis and regional interstitial glycerol levels in humans

Djurhuus

Gravholt

Nielsén

et al. 2002

American Journal of Physiology-Endocrinology and Metabolism

182

111

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Cortisol's effects on lipid metabolism are controversial and may involve stimulation of both lipolysis and lipogenesis. This study was undertaken to define the role of physiological hypercortisolemia on systemic and regional lipolysis in humans. We investigated seven healthy young male volunteers after an overnight fast on two occasions by means of microdialysis and palmitate turnover in a placebo-controlled manner with a pancreatic pituitary clamp involving inhibition with somatostatin and substitution of growth hormone, glucagon, and insulin at basal levels. Hydrocortisone infusion increased circulating concentrations of cortisol (888 ± 12 vs. 245 ± 7 nmol/l). Interstitial glycerol concentrations rose in parallel in abdominal (327 ± 35 vs. 156 ± 30 μmol/l; P = 0.05) and femoral (178 ± 28 vs. 91 ± 22 μmol/l; P = 0.02) adipose tissue. Systemic [3H]palmitate turnover increased (165 ± 17 vs. 92 ± 24 μmol/min; P = 0.01). Levels of insulin, glucagon, and growth hormone were comparable. In conclusion, the present study unmistakenly shows that cortisol in physiological concentrations is a potent stimulus of lipolysis and that this effect prevails equally in both femoral and abdominal adipose tissue.

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mentioning

confidence: 99%

Effects of cortisol on lipolysis and regional interstitial glycerol levels in humans

Djurhuus

Gravholt

Nielsén

et al. 2002

American Journal of Physiology-Endocrinology and Metabolism

182

111

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“…Quadriceps muscle strength during dynamic contractions (−13%), thigh muscle cross-sectional area (CSA) (−7%) and total work performed during 20 repeated dynamic contractions of the quadriceps (−24%) were all reduced in RTx compared to controls; furthermore, muscle strength was still 9% lower in RTx than in controls when expressed relative to thigh muscle CSA (2.1 vs. 2.3 Nm.cm −2 ). Strong relationships between muscle structure and function were reported for the first time in RTx (124). TheVo 2peak was correlated with: the muscle myofibrillar thigh volume (r = 0.84); cell sarcoplasm volume (r = 0.86); thigh total capillary number (r = 0.79), and total mitochondrial volume (r = 0.62).…”

Section: Peak Exercise Performance After Renal Transplantationmentioning

confidence: 77%

“…A low HR peak was found in RTx (137 b.min −1 ), but the rise in systolic BP with peak exercise to 190 mmHg was unremarkable. Horber et al undertook a comprehensive analysis of muscle function and ultrastructure in nine RTx patients (33.9 years, 60 months postRTx) (124). They foundVo 2peak during cycle ergometry was 32.8 ml.kg −1 .min −1 , or 82% of control values (124).…”

Section: Peak Exercise Performance After Renal Transplantationmentioning

confidence: 99%

“…Horber et al undertook a comprehensive analysis of muscle function and ultrastructure in nine RTx patients (33.9 years, 60 months postRTx) (124). They foundVo 2peak during cycle ergometry was 32.8 ml.kg −1 .min −1 , or 82% of control values (124). Quadriceps muscle strength during dynamic contractions (−13%), thigh muscle cross-sectional area (CSA) (−7%) and total work performed during 20 repeated dynamic contractions of the quadriceps (−24%) were all reduced in RTx compared to controls; furthermore, muscle strength was still 9% lower in RTx than in controls when expressed relative to thigh muscle CSA (2.1 vs. 2.3 Nm.cm −2 ).…”

Section: Peak Exercise Performance After Renal Transplantationmentioning

confidence: 99%

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Exercise Limitation Following Transplantation

Williams

McKenna

2012

Comprehensive Physiology

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Organ transplantation is one of the medical miracles or the 20th century. It has the capacity to substantially improve exercise performance and quality of life in patients who are severely limited with chronic organ failure. We focus on the most commonly performed solid‐organ transplants and describe peak exercise performance following recovery from transplantation. Across all of the common transplants, evaluated significant reduction in o 2 peak is seen (typically renal and liver 65%‐80% with heart and/or lung 50%‐60% of predicted). Those with the lowest o 2 peak pretransplant have the lowest o 2 peak posttransplant. Overall very few patients have a o 2 peak in the normal range. Investigation of the cause of the reduction of o 2 peak has identified many factors pre‐ and posttransplant that may contribute. These include organ‐specific factors in the otherwise well‐functioning allograft (e.g., chronotropic incompetence in heart transplantation) as well as allograft dysfunction itself (e.g., chronic lung allograft dysfunction). However, looking across all transplants, a pattern emerges. A low muscle mass with qualitative change in large exercising skeletal muscle groups is seen pretransplant. Many factor posttransplant aggravate these changes or prevent them recovering, especially calcineurin antagonist drugs which are key immunosuppressing agents. This results in the reduction of o 2 peak despite restoration of near normal function of the initially failing organ system. As such organ transplantation has provided an experiment of nature that has focused our attention on an important confounder of chronic organ failure‐skeletal muscle dysfunction. © 2012 American Physiological Society. Compr Physiol 2:1937‐1979, 2012.

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“…Chronotropic incompetence and alteration in diastolic function are central factors 21,22,25,26 . At the peripheral level, reduction of peripheral oxygen extraction occurs 17,21,22,[27][28][29] . An exaggerated neuroendocrine response 19 and reduced capacity of pulmonary diffusion 20,30 also seem to be involved in decreased tolerance to exercise.…”

mentioning

confidence: 99%

Adaptation to exercise following cardiac transplantation

Af¹,

Ja²

2000

Arq. Bras. Cardiol.

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Cardiac transplantation has been the treatment of choice for patients with terminal cardiac insufficiency, increasing survival time by more than 80% in the first year 1 and by more than 50% over ten years 2 . Following cardiac transplantation, the quality of life improves considerably, and many transplanted patients return to work becoming reintegrated into the community 3 . During regular activity, transplanted subjects have shown physical conditioning similar to that of healthy individuals 4-7 . Starling's axiom, "today's physiology will be tomorrow's medicine" 8 , emphasizes the need for knowledge about post-transplantation cardiovascular adaptations, to serve as the basis for clinical treatment and rehabilitation. The present article has the aim of discussing the state-of -the-art of this subject.Aerobic capacity -Aerobic capacity is the total amount of O 2 capable of being metabolized by an organism. Aerobic potency is the amount of 0 2 consumed per unit of time (VO 2 ). Maximal O 2 consumption (VO 2 max.) or maximal aerobic potency is the maximum VO 2 obtained in an endurance (of progressive loads) test, in which VO 2 reaches a maximal value without additional increase due to an additional work load. In tests in which the patient does not reach maximum oxygen consumption, as frequently occurs in cardiopathy patients and transplanted subjects, peak VO 2 is defined as the highest value of VO 2 obtained. Following cardiac transplantation, patients progress with a reduction of peak VO 2 9-15 of 30-50% [16][17][18][19][20][21][22] . In our study 6,7 , deficits were 32.4% and 25.7% at peak exercise and at the anaerobic threshold, respectively. Marzo et al 18 found a 35% reduction in the absolute values of the anaerobic threshold. Degré et al 23 reported an early and intense accumulation of lactate during exercise, attributed to increased production in active tissues and reduced clearance secondary to decreased blood flow in the liver and other inactive tissues. In our study 7 , VO 2 in light to moderate submaximal exercise (40 watt load) below the anaerobic threshold was 12.34 and 12.38ml/kg/ min, in transplanted and healthy subjects, respectively, without significant differences between these groups. Meyer et al 24 , working with a load of 50 watts, reported a VO 2 of 0.96 ±0.1 and 0.95±0.08 L/min -1 in transplanted and control subjects, respectively.The reduction of peak VO 2 is due to multiple factors, both central and peripheral. Chronotropic incompetence and alteration in diastolic function are central factors 21,22,25,26 . At the peripheral level, reduction of peripheral oxygen extraction occurs 17,21,22,[27][28][29] . An exaggerated neuroendocrine response 19 and reduced capacity of pulmonary diffusion 20,30 also seem to be involved in decreased tolerance to exercise.Heart Rate -Heart rate values at rest have been observed to be higher in transplanted compared with healthy individuals due to the absence of parasympathetic innervation and corresponding to the intrinsic frequency of the sinus node 17,23,[31...

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Impact of physical training on the ultrastructure of midthigh muscle in normal subjects and in patients treated with glucocorticoids.

Cited by 78 publications

References 36 publications

Effects of cortisol on lipolysis and regional interstitial glycerol levels in humans

Effects of cortisol on lipolysis and regional interstitial glycerol levels in humans

Exercise Limitation Following Transplantation

Adaptation to exercise following cardiac transplantation

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