Effects of sustained exercise on pulmonary clearance of aerosolized 99mTc-DTPA

1989 ◽  
Vol 67 (5) ◽  
pp. 2055-2059 ◽  
Author(s):  
A. M. Lorino ◽  
M. Meignan ◽  
P. Bouissou ◽  
G. Atlan
Keyword(s):  
Tidal Volume ◽  
Clearance Rate ◽  
Constant Load ◽  
Pulmonary Mechanics ◽  
Epithelial Permeability ◽  
Alveolar Epithelial ◽  
Pulmonary Clearance ◽  
Before And After ◽  
Pulmonary Volumes ◽  
Constant Load Exercise

The effects of intensive prolonged exercise on the pulmonary clearance rate of aerosolized 99mTc-labeled diethylenetriaminepentaacetate (99mTc-DTPA) and pulmonary mechanics were studied in seven healthy nonsmoking volunteers. 99mTc-DTPA clearance and pulmonary mechanics (lung volumes and compliance) were assessed before and after 75 min of constant-load exercise performed on a treadmill, corresponding to 75% of maximal O2 uptake. Because both clearance measurements were made in similar conditions of pulmonary blood flow, respiratory rate, and tidal volume, changes in clearance rate can be assumed to represent changes of alveolar epithelial permeability. After exercise, total, apical, and basal clearance were significantly increased (P less than 0.01, 0.05, and 0.05, respectively) and the increases in total clearance and tidal volume observed during exercise were significantly correlated (P less than 0.05). In contrast, no significant change was found in pulmonary mechanics. These results show that prolonged intensive exercise induces an increase in epithelial permeability, which appears to be related to the mechanical effects of sustained increased ventilation. Because no change was evidenced in pulmonary volumes or in lung elasticity, our results suggest that this increase may result from alteration of the intercellular tight junctions rather than from a surfactant deficiency.

Vitamin E does not prevent exercise-induced increase in pulmonary clearance

1994 ◽  
Vol 77 (5) ◽  
pp. 2219-2223 ◽  
Author(s):  
A. M. Lorino ◽  
M. Paul ◽  
L. Cocea ◽  
M. Scherrer-Crosbie ◽  
E. Dahan ◽  
...  
Keyword(s):  
Lipid Peroxidation ◽  
Vitamin E ◽  
Constant Load ◽  
Epithelial Permeability ◽  
Alveolar Epithelial ◽  
Pulmonary Clearance ◽  
Lung Epithelial ◽  
Before And After ◽  
Lung Epithelial Permeability ◽  
Exercise Induced

It has been observed that sustained exercise results in a prolonged increase in alveolar epithelial permeability, as assessed by the pulmonary clearance rate of aerosolized 99mTc-labeled diethylenetriaminepentaacetate (Lorino et al. J. Appl. Physiol. 67: 2055–2059, 1989). The involvement of lipid peroxidation in this increased permeability was tested in seven nonsmoking volunteers by comparing the exercise-induced increases in pulmonary 99mTc-diethylenetriaminepentaacetate clearance before and after a 3-wk supplementation with oral vitamin E (1,000 IU/day), according to a protocol designed as a single-blind crossover study. The 60-min exercise was performed on a treadmill at a constant load corresponding to 80% of maximal O2 uptake. Administration of vitamin E, a very important antioxidant, did not reduce the exercise-induced increase in lung clearance, suggesting that the exercise-induced increase in lung epithelial permeability does not primarily result from the occurrence of lipid peroxidation in the alveolar membrane. This result thus corroborates the hypothesis of an alteration of the intercellular tight junctions due to the mechanical effects of hyperventilation.

Relationship of end-expiratory pressure, lung volume, and 99mTc-DTPA clearance

1987 ◽  
Vol 63 (4) ◽  
pp. 1586-1590 ◽  
Author(s):  
J. A. Cooper ◽  
H. van der Zee ◽  
B. R. Line ◽  
A. B. Malik
Keyword(s):  
Lung Volume ◽  
Clearance Rate ◽  
Base Line ◽  
Lung Inflation ◽  
Alveolar Epithelial ◽  
Pulmonary Clearance ◽  
Residual Capacity ◽  
Dose Response Effect ◽  
Relationship Of ◽  
Line P

We investigated the dose-response effect of positive end-expiratory pressure (PEEP) and increased lung volume on the pulmonary clearance rate of aerosolized technetium-99m-labeled diethylenetriaminepentaacetic acid (99mTc-DTPA). Clearance of lung radioactivity was expressed as percent decrease per minute. Base-line clearance was measured while anesthetized sheep (n = 20) were ventilated with 0 cmH2O end-expiratory pressure. Clearance was remeasured during ventilation at 2.5, 5, 10, 15, or 20 cmH2O PEEP. Further studies showed stepwise increases in functional residual capacity (FRC) (P less than 0.05) measured at 0, 2.5, 5, 10, 15, and 20 cmH2O PEEP. At 2.5 cmH2O PEEP, the clearance rate was not different from that at base line (P less than 0.05), although FRC was increased from base line. Clearance rate increased progressively with increasing PEEP at 5, 10, and 15 cmH2O (P less than 0.05). Between 15 and 20 cmH2O PEEP, clearance rate was again unchanged, despite an increase in FRC. The pulmonary clearance of aerosolized 99mTc-DTPA shows a sigmoidal response to increasing FRC and PEEP, having both threshold and maximal effects. This relationship is most consistent with the hypothesis that alveolar epithelial permeability is increased by lung inflation.

The Effects of Creatine Supplementation on Cardiovascular, Metabolic, and Thermoregulatory Responses during Exercise in the Heat in Endurance-Trained Humans

2004 ◽  
Vol 14 (4) ◽  
pp. 443-460 ◽  
Author(s):  
L.P. Kilduff ◽  
E. Georgiades ◽  
N. James ◽  
R.H. Minnion ◽  
M. Mitchell ◽  
...  
Keyword(s):  
Prolonged Exercise ◽  
Sweat Rate ◽  
Creatine Supplementation ◽  
Cardiovascular Responses ◽  
Constant Load ◽  
Time To Exhaustion ◽  
Exercise Tests ◽  
Thermoregulatory Responses ◽  
Before And After ◽  
Constant Load Exercise

The effects of creatine (Cr) supplementation on cardiovascular, metabolic, and thermoregulatory responses, and on the capacity of trained humans to perform prolonged exercise in the heat was examined. Endurance-trained males (n = 21) performed 2 constant-load exercise tests to exhaustion at 63 ± 5 % VO2max in the heat (ambient temperature: 30.3 ± 0.5 °C) before and after 7 d of Cr (20 g · d–1 ’ Cr + 140 g • d–1 glucose polymer) or placebo. Cr increased intraccl-lular water and reduced thermoregulatory and cardiovascular responses (e.g., heart rate, rectal temperature, sweat rate) but did not significantly increase time to exhaustion (47.0 ± 4.7 min vs. 49.7 ± 7.5 min, P = 0.095). Time to exhaustion was increased significantly in subjects whose estimated intramuscular Cr levels were substantially increased (“responders”: 47.3 ± 4.9 min vs. 51.7 ± 7.4 min, P = 0.031). Cr-induced hyperhydration can result in a more efficient thermoregulatory response during prolonged exercise in the heat.

scholarly journals Comparison of oxygen uptake at the onset of decrement-load and constant-load exercise.

2007 ◽  
pp. 169-174
Author(s):  
T Yano ◽  
H Ogata ◽  
R Matsuura ◽  
T Arimitsu ◽  
T Yunoki
Keyword(s):  
Steady State ◽  
Oxygen Uptake ◽  
Power Output ◽  
Fast Rate ◽  
Constant Load ◽  
Oxygen Debt ◽  
Heavy Exercise ◽  
Post Exercise ◽  
Before And After ◽  
Constant Load Exercise

The purpose of the present study was to examine whether the level of oxygen uptake (V(.)(O2) at the onset of decrement-load exercise (DLE) is lower than that at the onset of constant-load exercise (CLE), since power output, which is the target of V(.)(O2) response, is decreased in DLE. CLE and DLE were performed under the conditions of moderate and heavy exercise intensities. Before and after these main exercises, previous exercise and post exercise were performed at 20 watts. DEL was started at the same power output as that for CLE and power output was decreased at a rate of 15 watts per min. V(.)(O2) in moderate CLE increased at a fast rate and showed a steady state, while V(.)(O2) in moderate DLE increased and decreased linearly. V(.)(O2) at the increasing phase in DLE was at the same level as that in moderate CLE. V(.)(O2) immediately after moderate DLE was higher than that in the previous exercise by 98+/-77.5 ml/min. V(.)(O2) in heavy CLE increased rapidly at first and then slowly increased, while V(.)(O2) in heavy DLE increased rapidly, showing a temporal convexity change, and decreased linearly. V(.)(O2) at the increasing phase of heavy DLE was the same level as that in heavy CLE. V(.)(O2) immediately after heavy DLE was significantly higher than that in the previous exercise by 156+/-131.8 ml/min. Thus, despite the different modes of exercise, V(.)(O2) at the increasing phase in DLE was at the same level as that in CLE due to the effect of the oxygen debt expressed by the higher level of V(.)(O2) at the end of DLE than that in the previous exercise.

Effects of elastase-induced emphysema on airway responsiveness to methacholine in rats

1989 ◽  
Vol 66 (2) ◽  
pp. 606-612 ◽  
Author(s):  
S. Bellofiore ◽  
D. H. Eidelman ◽  
P. T. Macklem ◽  
J. G. Martin
Keyword(s):  
Lung Volume ◽  
Brown Norway ◽  
Pulmonary Mechanics ◽  
Maximum Increase ◽  
Before And After ◽  
Airway Response ◽  
Residual Capacity ◽  
Airway Responses ◽  
Norway Rats ◽  
Concentration Response Curve

We examined the effects of elastase-induced emphysema on lung volumes, pulmonary mechanics, and airway responses to inhaled methacholine (MCh) of nine male Brown Norway rats. Measurements were made before and weekly for 4 wk after elastase in five rats. In four rats measurements were made before and at 3 wk after elastase; in these same animals the effects of changes in end-expiratory lung volume on the airway responses to MCh were evaluated before and after elastase. Airway responses were determined from peak pulmonary resistance (RL) calculated after 30-s aerosolizations of saline and doubling concentrations of MCh from 1 to 64 mg/ml. Porcine pancreatic elastase (1 IU/g) was administered intratracheally. Before elastase RL rose from 0.20 +/- 0.02 cmH2O.ml-1.s (mean +/- SE; n = 9) to 0.57 +/- 0.06 after MCh (64 mg/ml). A plateau was observed in the concentration-response curve. Static compliance and the maximum increase in RL (delta RL64) were significantly correlated (r = 0.799, P less than 0.01). Three weeks after elastase the maximal airway response to MCh was enhanced and no plateau was observed; delta RL64 was 0.78 +/- 0.07 cmH2O.ml-1.s, significantly higher than control delta RL64 (0.36 +/- 0.7, P less than 0.05). Before elastase, increase of end-expiratory lung volume to functional residual capacity + 1.56 ml (+/- 0.08 ml) significantly reduced RL at 64 mg MCh/ml from 0.62 +/- 0.05 cmH2O.ml-1.s to 0.50 +/- 0.03, P less than 0.05.(ABSTRACT TRUNCATED AT 250 WORDS)

Clearance of charged and uncharged dextrans from normal and injured lungs

1990 ◽  
Vol 68 (1) ◽  
pp. 341-347 ◽  
Author(s):  
M. P. Barrowcliffe ◽  
G. D. Zanelli ◽  
D. Ellison ◽  
J. G. Jones
Keyword(s):  
Clearance Rate ◽  
Dextran Sulfate ◽  
Molecular Size ◽  
Confidence Limits ◽  
Half Time ◽  
Capillary Barrier ◽  
Solute Transfer ◽  
Molecular Charge ◽  
Before And After ◽  
Alveolar Capillary

To examine how molecular charge affects the transfer of molecules across the alveolar-capillary barrier, we prepared the following dextrans of equivalent molecular size (mol wt 10,000) but varying molecular charge: neutral dextran, cationic DEAE dextran, and anionic dextran sulfate. These were labeled with 99mTc. The lungs of three groups of anesthetized rabbits were insufflated with dextran aerosols, with six rabbits receiving each type, and the half-time pulmonary clearance (t1/2) was measured. Control t1/2's (95% confidence limits) were 95 (74-120), 227 (192-268), and 291 (246-345) min for neutral, cationic, and anionic dextrans, respectively. One week later, when the same animals were restudied 4 h after 3 micrograms/kg iv endotoxin, t1/2's were 102 (75-139), 167 (149-187), and 126 (102-154) min, respectively. After 30 min during this repeat study, animals were ventilated with 20 breaths of cigarette smoke, which acutely increased the clearance rate to 34 (26-46), 25 (20-31), and 13 (7-24) min, respectively. Mean carboxyhemoglobin levels were not significantly different in the three groups: 13.6, 12.7, and 11.1%, respectively. These results demonstrated that neutral dextrans showed the same clearance rate before and after endotoxin, whereas the charged dextrans had a significantly faster clearance after endotoxin. After smoke exposure the anionic dextran left the lung more rapidly than the neutral dextran. Thus molecular charge affects solute transfer across the alveolar-capillary barrier in both normal and injured lungs, and an effect of endotoxin on the lung can be detected with charged dextrans but not with neutral dextran.

Long-term mild jogging increases insulin action despite no influence on body mass index or VO2 max

1989 ◽  
Vol 66 (5) ◽  
pp. 2206-2210 ◽  
Author(s):  
Y. Oshida ◽  
K. Yamanouchi ◽  
S. Hayamizu ◽  
Y. Sato
Keyword(s):  
Body Mass Index ◽  
Body Mass ◽  
Clearance Rate ◽  
Insulin Action ◽  
Metabolic Clearance ◽  
Metabolic Clearance Rate ◽  
Before And After ◽  
Plasma Insulin Levels ◽  
Improve Glucose Tolerance

Physical training has been shown to improve glucose tolerance and insulin sensitivity. In the present study, insulin action was determined using the euglycemic clamp technique in six untrained nonobese subjects before, during, and after long-term mild regular jogging. After 1 yr of jogging, steady-state plasma insulin levels (I) decreased significantly, and the metabolic clearance rate of insulin was increased by 87%, although insulin infusion rate during the clamp was constant for each individual. The amount of glucose infused (glucose metabolism, M) tended to increase from 6.16 +/- 0.94 to 8.15 +/- 1.94 mg.kg-1.min-1 after regular jogging for 1 yr, although that was not statistically significant. However, M/I increases significantly from 0.060 +/- 0.012 to 0.184 +/- 0.056 (P less than 0.05) after 1 yr. The concentrations of plasma free fatty acids during the hyperinsulinemic clamp decreased more significantly after 1 yr of jogging (P less than 0.05). The concentrations of plasma glycerol decreased gradually before and after long-term regular jogging, showing only a 50–60% reduction in 120 min. Therefore, long-term mild regular jogging, which did not influence either body mass index or maximal O2 uptake, appears to improve insulin action in both carbohydrate and lipid metabolism and to increase the metabolic clearance rate of insulin.

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