Impaired pulmonary oxygen uptake kinetics and reduced peak aerobic power during small muscle mass exercise in heart transplant recipients

2007 ◽  
Vol 103 (5) ◽  
pp. 1722-1727 ◽  
Author(s):  
Nicholas G. Jendzjowsky ◽  
Corey R. Tomczak ◽  
Richard Lawrance ◽  
Dylan A. Taylor ◽  
Wayne J. Tymchak ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Oxygen Uptake ◽  
Phase Ii ◽  
Heart Transplant ◽  
Moderate Intensity ◽  
Peak Exercise ◽  
Transplant Recipients ◽  
Pulmonary Oxygen Uptake ◽  
Significant Difference ◽  
Heart Transplant Recipients

We examined peak and reserve cardiovascular function and skeletal muscle oxygenation during unilateral knee extension (ULKE) exercise in five heart transplant recipients (HTR, mean ± SE; age: 53 ± 3 years; years posttransplant: 6 ± 4) and five age- and body mass-matched healthy controls (CON). Pulmonary oxygen uptake (V̇o2p), heart rate (HR), stroke volume (SV), cardiac output (Q̇), and skeletal muscle deoxygenation (HHb) kinetics were assessed during moderate-intensity ULKE exercise. Peak exercise and reserve V̇o2p, Q̇, and systemic arterial-venous oxygen difference (a-vO2diff) were 23–52% lower ( P < 0.05) in HTR. The reduced Q̇ and a-vO2diff reserves were associated with lower HR and HHb reserves, respectively. The phase II V̇o2p time delay was greater (HTR: 38 ± 2 vs. CON: 25 ± 1 s, P < 0.05), while time constants for phase II V̇o2p (HTR: 54 ± 8 vs. CON: 31 ± 3 s), Q̇ (HTR: 66 ± 8 vs. CON: 28 ± 4 s), and HHb (HTR: 27 ± 5 vs. CON: 13 ± 3 s) were significantly slower in HTR. The HR half-time was slower in HTR (113 ± 21 s) vs. CON (21 ± 2 s, P < 0.05); however, no significant difference was found between groups for SV kinetics (HTR: 39 ± 8 s vs. CON 31 ± 6 s). The lower peak V̇o2p and prolonged V̇o2p kinetics in HTR were secondary to impairments in both cardiovascular and skeletal muscle function that result in reduced oxygen delivery and utilization by the active muscles.

Exercise Training Improves Pulmonary Oxygen Uptake Kinetcs In Heart Transplant Recipients

2007 ◽  
Vol 39 (Supplement) ◽  
pp. S282
Author(s):  
Corey R. Tomczak ◽  
Kenneth J. Riess ◽  
Nicholas G. Jendzjowsky ◽  
Wayne Tymchak ◽  
Daniel Kim ◽  
...  
Keyword(s):  
Exercise Training ◽  
Oxygen Uptake ◽  
Heart Transplant ◽  
Transplant Recipients ◽  
Pulmonary Oxygen Uptake ◽  
Heart Transplant Recipients

Enhanced brain natriuretic peptide response to peak exercise in heart transplant recipients

1998 ◽  
Vol 85 (6) ◽  
pp. 2270-2276 ◽  
Author(s):  
Bernard Geny ◽  
Anne Charloux ◽  
Eliane Lampert ◽  
Jean Lonsdorfer ◽  
Pascal Haberey ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Heart Transplantation ◽  
Left Ventricular Mass ◽  
Heart Transplant ◽  
Left Ventricular Mass Index ◽  
Left Ventricular ◽  
Peak Exercise ◽  
Transplant Recipients ◽  
Heart Transplant Recipients

We investigated the atrial (ANP) and brain natriuretic peptides (BNP), catecholamines, heart rate, and blood pressure responses to graded upright maximal cycling exercise of eight matched healthy subjects and cardiac-denervated heart transplant recipients (HTR). Baseline heart rate and diastolic blood pressure, together with ANP (15.2 ± 3.7 vs. 4.4 ± 0.8 pmol/l; P < 0.01) and BNP (14.3 ± 2.6 vs. 7.4 ± 0.6 pmol/l; P< 0.01), were elevated in HTR, but catecholamine levels were similar in both groups. Peak exercise O2uptake and heart rate were lower in HTR. Exercise-induced maximal ANP increase was similar in both groups (167 ± 34 vs. 216 ± 47%). Enhanced BNP increase was significant only in HTR (37 ± 8 vs. 16 ± 8%; P < 0.05). Similar norepinephrine but lower peak epinephrine levels were observed in HTR. ANP and heart rate changes from rest to 75% peak exercise were negatively correlated ( r = −0.76, P < 0.05), and BNP increase was correlated with left ventricular mass index ( r = 0.83, P < 0.01) after heart transplantation. Although ANP increase was not exaggerated, these data support the idea that the chronotropic limitation secondary to sinus node denervation might stimulate ANP release during early exercise in HTR. Furthermore, the BNP response to maximal exercise, which is related to the left ventricular mass index of HTR, is enhanced after heart transplantation.

Pulmonary oxygen uptake kinetics

2017 ◽  
Author(s):  
Alan R Barker ◽  
Neil Armstrong
Keyword(s):  
Oxygen Uptake ◽  
Oxidative Phosphorylation ◽  
Children And Adolescents ◽  
Phase Ii ◽  
Slow Component ◽  
Moderate Intensity ◽  
Heavy Exercise ◽  
Moderate Intensity Exercise ◽  
Pulmonary Oxygen Uptake ◽  
Age Related

The pulmonary oxygen uptake (pV̇O2) kinetic response to exercise provides valuable non-invasive insight into the control of oxidative phosphorylation and determinants of exercise tolerance in children and adolescents. Few methodologically robust studies have investigated pV̇O2 kinetics in children and adolescents, but age- and sex-related differences have been identified. There is a clear age-related slowing of phase II pV̇O2 kinetics during heavy and very heavy exercise, with a trend showing during moderate intensity exercise. During heavy and very heavy exercise the oxygen cost is higher for phase II and the pV̇O2 component is truncated in children. Sex-related differences occur during heavy, but not moderate, intensity exercise, with boys having faster phase II pV̇O2 kinetics and a smaller pV̇O2 slow component compared to girls. The mechanisms underlying these differences are likely related to changes in phosphate feedback controllers of oxidative phosphorylation, muscle oxygen delivery, and/or muscle fibre recruitment strategies.

Ischemic Heart Failure Etiology Affects Phase II VO2 Kinetics in Heart Transplant Recipients

2006 ◽  
Vol 38 (Supplement) ◽  
pp. S359
Author(s):  
Corey R. Tomczak ◽  
Nicholas G. Jendzjowsky ◽  
Daniel Kim ◽  
Wayne Tymchak ◽  
Robert G. Haennel ◽  
...  
Keyword(s):  
Heart Failure ◽  
Phase Ii ◽  
Heart Transplant ◽  
Ischemic Heart ◽  
Ischemic Heart Failure ◽  
Transplant Recipients ◽  
Vo2 Kinetics ◽  
Heart Transplant Recipients

scholarly journals PO-098 Effect of HIIT on mitochondrial telomerase of skeletal muscle in aged rats

2018 ◽  
Vol 1 (3) ◽  
Author(s):  
Yiyi Liu ◽  
Hao Su ◽  
Zhongye Jiang ◽  
Tianhao Wen ◽  
Jia Shao
Keyword(s):  
Skeletal Muscle ◽  
Oxygen Uptake ◽  
Intervention Group ◽  
Exercise Group ◽  
Moderate Intensity ◽  
Control Group ◽  
Moderate Intensity Exercise ◽  
Aging Rats ◽  
Age Related ◽  
Significant Difference

Objective The HIIT and moderate-intensity exercise are two different exercise models among the public fitness. In recent years, HIIT become more and more popular, unfortunately, there is a tremendous lack of research being done effects of mitochondrial reverse transcriptase (TERT) on age-related degeneration of skeletal muscle by HIIT. The purpose of this study was to compare the HIIT group and moderate-intensity group, and research difference of telomerase expression and cardiopulmonary endurance between the exercise group and the quiet control group was discussed. Methods  fifty-nine male Wistar rats were divided into three groups at random: control group (Q=19), moderate-intensity intervention group (M=20), and HIIT intervention group (H=20). The rats in Q group did not any exercise, and the rats in M group developed the exercise with 60% VO2max intensity for 8 weeks. H group did a training program for an 8-week exercise with alternating 40%, 60%, and 80% VO2max intensities. The rats in the experimental group were exercised for 50 minutes every day and trained for 5 days per week. After the baseline value group was sampled, each group of rats was selected after the training reached the specified number of weeks (4 and 8 weeks), and the maximum oxygen uptake test was performed before the material was taken. Single factor analysis of variance were used to assess differences in VO2max, and expression of protein between conditions. Results It was found that H group VO2max was significantly higher than M group and Q group (P<0.05). At same time, the mTERT expression of the M group at the 4th week was significantly higher than that of the Q group (P<0.05). The mTERT expression in group H was significantly higher than that in group Q at week 8 (P<0.05).There was no significant difference between the H group and the Q group at 8th week (P<0.05). Conclusions 1. HIIT exercise lasting for 8 weeks can effectively inhibit the decrease of maximal oxygen uptake in aging rats compared with moderate exercise. 2. HIIT training for 8 weeks promotes the expression of mTERT; 3. The maintenance of VO2max in aging rats may be related to the enhancement of mitochondrial antioxidant function by HIIT-promoted TERT to mitochondrial translocation.

Predictors for Peak Oxygen Uptake in De Novo Heart Transplant Recipients (the HITTS Study)

2017 ◽  
Vol 36 (4) ◽  
pp. S176
Author(s):  
K. Rolid ◽  
M. Yardley ◽  
A.R. Authen ◽  
I. Grov ◽  
M.R. Kunszt ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
Heart Transplant ◽  
De Novo ◽  
Peak Oxygen Uptake ◽  
Transplant Recipients ◽  
Heart Transplant Recipients

scholarly journals A short period of high-intensity interval training improves skeletal muscle mitochondrial function and pulmonary oxygen uptake kinetics

2016 ◽  
Vol 120 (11) ◽  
pp. 1319-1327 ◽  
Author(s):  
Peter M. Christensen ◽  
Robert A. Jacobs ◽  
Thomas Bonne ◽  
Daniela Flück ◽  
Jens Bangsbo ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Oxygen Uptake ◽  
Mitochondrial Function ◽  
High Intensity ◽  
System Capacity ◽  
Oxidative Enzymes ◽  
Moderate Intensity ◽  
Pulmonary Oxygen Uptake ◽  
Short Period ◽  
Before And After

The aim of the present study was to examine whether improvements in pulmonary oxygen uptake (V̇o2) kinetics following a short period of high-intensity training (HIT) would be associated with improved skeletal muscle mitochondrial function. Ten untrained male volunteers (age 26 ± 2 yr; mean ± SD) performed six HIT sessions (8-12 × 60 s at incremental test peak power; 271 ± 52 W) over a 2-wk period. Before and after the HIT period, V̇o2 kinetics was modeled during moderate-intensity cycling (110 ± 19 W). Mitochondrial function was assessed with high-resolution respirometry (HRR), and maximal activities of oxidative enzymes citrate synthase (CS) and cytochrome c oxidase (COX) were accordingly determined. In response to HIT, V̇o2 kinetics became faster (τ: 20.4 ± 4.4 vs. 28.9 ± 6.1 s; P < 0.01) and fatty acid oxidation (ETFP) and leak respiration (LN) both became elevated ( P < 0.05). Activity of CS and COX did not increase in response to training. Both before and after the HIT period, fast V̇o2 kinetics (low τ values) was associated with large values for ETFP, electron transport system capacity (ETS), and electron flow specific to complex II (CIIP) ( P < 0.05). Collectively, these findings support that selected measures of mitochondrial function obtained with HRR are important for fast V̇o2 kinetics and better markers than maximal oxidative enzyme activity in describing the speed of the V̇o2 response during moderate-intensity exercise.

Sign in / Sign up

Export Citation Format

Share Document