Plasma and platelet catecholamine and catecholamine sulfate response to various exercise tests

1994 ◽  
Vol 267 (4) ◽  
pp. E537-E543
Author(s):  
G. Strobel ◽  
B. Friedmann ◽  
J. Jost ◽  
P. Bartsch
Keyword(s):  
Average Power ◽  
Plasma Norepinephrine ◽  
Plasma Catecholamine ◽  
O2 Consumption ◽  
Exercise Tests ◽  
Trained Subjects ◽  
Low Intensity ◽  
Average Power Output ◽  
Response To Exercise ◽  
Sympathoadrenergic Activity

We tested the hypothesis that platelet and plasma catecholamine sulfates (CA-S) and platelet catecholamines (CA) reflect the overall sympathoadrenergic activation by exercise of 1 h duration. Ten well-trained subjects performed a low-intensity [62% maximum O2 consumption (VO2max); LI] and a high-intensity exercise test (77% VO2max; HI) and two tests at a similar average power output that consisted of 20 min at 77% VO2max and 40 min at 62% VO2max (HI/LI) and vice versa (LI/HI). Plasma norepinephrine sulfate (NE-S) increased to higher levels after HI than after LI exercise (15.5 +/- 2.1 vs. 8.9 +/- 0.7 nmol/l). Immediately after HI/LI and LI/HI plasma NE-S was similarly increased (9.59 +/- 1.1 vs. 9.96 +/- 1.3 nmol/l), whereas norepinephrine was higher after LI/HI than after HI/LI (23.0 +/- 3.2 vs. 15.7 +/- 2.3 nmol/l). Platelet CA and CA-S were increased only after HI. In conclusion, the plasma NE-S response to exercise parallels the overall sympathetic activation. These results support the hypothesis that plasma NE-S measured immediately after exercise reflects the overall sympathoadrenergic activity over prolonged periods of exercise. Platelet CA and CA-S poorly reflect sympathoadrenergic activation.

Catecholamine-fuel interrelationships during exercise in fasting men

1980 ◽  
Vol 48 (1) ◽  
pp. 109-113 ◽  
Author(s):  
J. M. Pequignot ◽  
L. Peyrin ◽  
G. Peres
Keyword(s):  
Maximal Oxygen Consumption ◽  
Plasma Catecholamines ◽  
Plasma Free Fatty Acid ◽  
Work Load ◽  
Bicycle Ergometer ◽  
Plasma Norepinephrine ◽  
Plasma Catecholamine ◽  
Adrenergic Response ◽  
Response To Exercise

Adrenergic response to exercise and the relationships between plasma catecholamines and blood energetic substrates were studied in sedentary men after 15 h of fasting. Subjects pedaled a bicycle ergometer until exhaustion at a work load approximating 80% maximal oxygen consumption. Working ability was diminished by the fast (P less than 0.025). Resting plasma norepinephrine level was increased by fasting. During exercise plasma epinephrine (E) and norepinephrine (NE) concentrations were more elevated in fasting subjects than in fed subjects. Plasma catecholamine (CA) levels in fasting men correlated with blood glucose, blood lactate, and plasma glycerol concentrations. There was no significative correlation between CA and plasma free fatty acid (FFA) levels. The increased adrenergic activity in fasting subjects correlated with reduced endurance time. This study emphasizes the role of CA release, probably combined with other hormonal factors, in the mobilization of energy substrates during submaximal exercise.

Physiological responses to cold stress during prolonged intermittent low- and high-intensity walking

1997 ◽  
Vol 272 (6) ◽  
pp. R2025-R2033 ◽  
Author(s):  
A. S. Weller ◽  
C. E. Millard ◽  
M. A. Stroud ◽  
P. L. Greenhaff ◽  
I. A. Macdonald
Keyword(s):  
Rectal Temperature ◽  
Intermittent Exercise ◽  
Physiological Responses ◽  
Plasma Norepinephrine ◽  
O2 Consumption ◽  
Exercise Protocol ◽  
Marked Influence ◽  
Low Intensity ◽  
Grade 5 ◽  
Walking Exercise

In a previous study [Am. J. Physiol. 272 (Regulatory Integrative Comp. Physiol. 41): R226-R233, 1997], the physiological responses to 240 min of intermittent low-intensity walking exercise in a cold (+5 degrees C), wet, and windy environment (Cold) may have been influenced by a 120-min preceding phase of intermittent higher-intensity exercise. Furthermore, the physiological responses observed during this latter phase may have been different if it had been more prolonged. To address these questions, active men attempted a 360-min intermittent (15 min of rest, 45 min of exercise) exercise protocol in Cold and a thermoneutral environment (+15 degrees C, Neutral) at a low (0% grade, 5 km/h; Low; n = 14) and a higher (10% grade, 6 km/h; High; n = 10) intensity. During Low, rectal temperature was lower in Cold than in Neutral, whereas O2 consumption, carbohydrate oxidation, plasma norepinephrine and epinephrine, and blood lactate were higher. During High, Cold had a similar but less marked influence on the thermoregulatory responses to exercise than during Low. In conclusion, the physiological responses to Low are similarly influenced by Cold whether or not they are preceded by High. Furthermore, during intermittent exercise up to an intensity of approximately 60% of peak O2 consumption, a cold, wet, and windy environment will influence the physiological responses to exercise and potentially impair performance.

Endurance run increases circulating IL-6 and IL-1ra but downregulates ex vivo TNF-alpha and IL-1 beta production

1995 ◽  
Vol 79 (5) ◽  
pp. 1497-1503 ◽  
Author(s):  
J. P. Drenth ◽  
S. H. Van Uum ◽  
M. Van Deuren ◽  
G. J. Pesman ◽  
J. Van der Ven-Jongekrijg ◽  
...  
Keyword(s):  
Vascular Resistance ◽  
Ex Vivo ◽  
Plasma Catecholamines ◽  
Plasma Norepinephrine ◽  
O2 Consumption ◽  
Esophageal Temperature ◽  
Trained Subjects ◽  
Norepinephrine Concentration ◽  
Fluid Losses ◽  
Cutaneous Vascular Resistance

This investigation determined the manner in which the cardiovascular system copes with the dehydration-induced reductions in cardiac output (Q) during prolonged exercise in the heat. On two separate occasions, seven endurance-trained subjects (maximal O2 consumption 4.70 +/- 0.41 l/min) cycled in the heat (35 degrees C) for 2 h, beginning at 62 +/- 2% maximal O2 consumption. During exercise, they randomly received either 0.2 liter of fluid and became dehydrated by 4.9 +/- 0.2% of their body weight [i.e., dehydration trial (DE)] or 3.6 +/- 0.4 liter of fluid and replaced 95% of fluid losses [i.e., euhydration trial (EU)]. During the 10- to 120-min period of EU, Q, mean arterial pressure (MAP), systemic vascular resistance (SVR), cutaneous vascular resistance (CVR), and plasma catecholamines did not change while esophageal temperature stabilized at 38.0 +/- 0.1 degrees C. Conversely, after 120 min of DE, Q and MAP were reduced 18 +/- 3 and 5 +/- 2%, respectively, compared with EU (P < 0.05). This was associated with a significantly higher SVR (17 +/- 6%) and plasma norepinephrine concentration (50 +/- 19%, P < 0.05). In addition, CVR was also significantly higher (126 +/- 16 vs. 102 +/- 6% of 20-min value; P < 0.05) during DE despite a 1.2 +/- 0.1 degrees C greater esophageal temperature (P < 0.05). In conclusion, significant reductions in Q are accompanied by significant increases in SVR and plasma norepinephrine and a slight although significant decline in MAP. The cutaneous circulation participates in this systemic vasoconstriction as indicated by increases in CVR despite significant hyperthermia.

Exercise effects on chromium excretion of trained and untrained men consuming a constant diet

1988 ◽  
Vol 64 (1) ◽  
pp. 249-252 ◽  
Author(s):  
R. A. Anderson ◽  
N. A. Bryden ◽  
M. M. Polansky ◽  
P. A. Deuster
Keyword(s):  
Physical Fitness ◽  
Control Diet ◽  
Exercise Bout ◽  
O2 Consumption ◽  
Sedentary Control ◽  
Trained Subjects ◽  
Daily Diet ◽  
Response To Exercise ◽  
Trained Runners ◽  
Sedentary Subjects

Chromium excretion of eight trained and five sedentary men was determined on rest days and after exercise to exhaustion at 90% of maximum O2 consumption (VO2max) to determine if degree of physical fitness affects urinary Cr losses. Subjects were fed a constant daily diet containing approximately 9 micrograms Cr/1,000 kcal. VO2max of the trained runners was in the good or above range based on their age and that of the sedentary subjects was average or below. While consuming the control diet, basal urinary Cr excretion of subjects who exercise regularly was significantly lower than that of the sedentary control subjects, 0.09 +/- 0.01 and 0.21 +/- 0.03 microgram/day (mean +/- SE), respectively. When subjects consumed self-chosen diets, basal urinary Cr excretion of the trained subjects was also significantly lower than that of the untrained subjects. Daily urinary Cr excretion of trained subjects was significantly higher on the day of a single exercise bout at 90% VO2max compared with nonexercise days, 0.12 +/- 0.02 and 0.09 +/- 0.01 microgram/day, respectively. Urinary Cr excretion of sedentary subjects was not altered after controlled exercise. These data demonstrate that basal urinary Cr excretion and excretion in response to exercise are related to VO2max and therefore degree of physical fitness.

Dehydration reduces cardiac output and increases systemic and cutaneous vascular resistance during exercise

1995 ◽  
Vol 79 (5) ◽  
pp. 1487-1496 ◽  
Author(s):  
J. Gonzalez-Alonso ◽  
R. Mora-Rodriguez ◽  
P. R. Below ◽  
E. F. Coyle
Keyword(s):  
Cardiac Output ◽  
Vascular Resistance ◽  
Plasma Catecholamines ◽  
Plasma Norepinephrine ◽  
O2 Consumption ◽  
Esophageal Temperature ◽  
Trained Subjects ◽  
Norepinephrine Concentration ◽  
Fluid Losses ◽  
Cutaneous Vascular Resistance

This investigation determined the manner in which the cardiovascular system copes with the dehydration-induced reductions in cardiac output (Q) during prolonged exercise in the heat. On two separate occasions, seven endurance-trained subjects (maximal O2 consumption 4.70 +/- 0.41 l/min) cycled in the heat (35 degrees C) for 2 h, beginning at 62 +/- 2% maximal O2 consumption. During exercise, they randomly received either 0.2 liter of fluid and became dehydrated by 4.9 +/- 0.2% of their body weight [i.e., dehydration trial (DE)] or 3.6 +/- 0.4 liter of fluid and replaced 95% of fluid losses [i.e., euhydration trial (EU)]. During the 10- to 120-min period of EU, Q, mean arterial pressure (MAP), systemic vascular resistance (SVR), cutaneous vascular resistance (CVR), and plasma catecholamines did not change while esophageal temperature stabilized at 38.0 +/- 0.1 degrees C. Conversely, after 120 min of DE, Q and MAP were reduced 18 +/- 3 and 5 +/- 2%, respectively, compared with EU (P < 0.05). This was associated with a significantly higher SVR (17 +/- 6%) and plasma norepinephrine concentration (50 +/- 19%, P < 0.05). In addition, CVR was also significantly higher (126 +/- 16 vs. 102 +/- 6% of 20-min value; P < 0.05) during DE despite a 1.2 +/- 0.1 degrees C greater esophageal temperature (P < 0.05). In conclusion, significant reductions in Q are accompanied by significant increases in SVR and plasma norepinephrine and a slight although significant decline in MAP. The cutaneous circulation participates in this systemic vasoconstriction as indicated by increases in CVR despite significant hyperthermia.

The Effect of Superoxygenated Water on Blood Gases, Lactate, and Aerobic Cycling Performance

2007 ◽  
Vol 2 (4) ◽  
pp. 377-385 ◽  
Author(s):  
Lars R. McNaughton ◽  
Steve Kenney ◽  
Jason Siegler ◽  
Adrian W. Midgley ◽  
Ric J. Lovell ◽  
...  
Keyword(s):  
Exercise Test ◽  
Power Output ◽  
Average Power ◽  
Rest Period ◽  
Cycling Performance ◽  
Exercise Tests ◽  
Double Blind ◽  
Maximal Power Output ◽  
Physiological Variables ◽  
Average Power Output

Context:Recently, superoxygenated-water beverages have emerged as a new purported ergogenic substance.Purpose:This study aimed to determine the effects of superoxygenated water on submaximal endurance performance.Methods:Eleven active male subjects, VO2max 52.6 ± 4.8 mL · kg−1 · min−1, height 180.0 ± 2.0 cm, weight 76.0 ± 7.0 kg, age 24 ± 1.0 y (mean ± SD), completed a 45-min cycle-ergometry exercise test at 70% of their previously predicted maximal power output with a 10-min rest period, followed by a 15-min time trial (TT). Thirty minutes before the exercise test subjects consumed 15 mL of either superoxygenated water (E) or placebo (P; water mixed with low-chlorine solution). Subjects then completed the test again a week later for the other condition (double-blind, randomized). The physiological variables measured during exercise were VO2, VCO2, respiratory-exchange ratio (RER), VE, PO2, PCO2, blood lactate (bLa–), and heart rate (HR). Mean distance covered and the average power output for the 15-min TT were also measured as performance indicators.Results:There were no significant differences in VO2, VCO2, RER, VE, bLa−, PO2, and HR (P > .05) during the exercise tests. Neither were there any significant improvements in the total distance covered (P 9.01 ± 0.74 km vs E 8.96 ± 0.68 km, P > .05) or the average power output (P 186.7 ± 35.8 W vs E 179.0 ± 25.9 W, P > .05) during the 15-min TT.Conclusion:Based on these results the authors conclude that consuming 15 mL of superoxygenated water does not enhance submaximal or maximal TT cycling performance.

Carbohydrate-Electrolyte Feedings and 1h Time Trial Cycling Performance

2004 ◽  
Vol 14 (5) ◽  
pp. 541-549 ◽  
Author(s):  
Ben Desbrow ◽  
Sally Anderson ◽  
Jennifer Barrett ◽  
Elissa Rao ◽  
Mark Hargreaves
Keyword(s):  
Power Output ◽  
High Intensity ◽  
Average Power ◽  
Time Trial ◽  
Cycling Performance ◽  
Dietary Regimen ◽  
Trained Subjects ◽  
Sports Drink ◽  
Average Power Output ◽  
Glucose Availability

The effects of a commercial sports drink on performance in high-intensity cycling was investigated. Nine well-trained subjects were asked to complete a set amount of work as fast as possible (time trial) following 24 h of dietary (subjects were provided with food, energy 57.4 ± 2.4 kcal/kg and carbohydrate 9.1 ± 0.4 g/kg) and exercise control. During exercise, subjects were provided with 14 mL/kg of either 6% carbohydrate-electrolyte (CHO-E) solution or carbohydrate-free placebo (P). Results showed that subjects’ performances did not greatly improve (time, 62:34 ± 6:44 min:sec (CHO-E) vs. 62:40 ± 5:35 min:sec (P); average power output, 283.0 ± 25.0 W (CHO-E) vs. 282.9 ± 29.3 W (P), P > 0.05) while consuming the sports drink. It was concluded that CHO-E consumption throughout a 1-h time trial, following a pre-exercise dietary regimen designed to optimize glucose availability, did not improve time or power output to a greater degree than P in well-trained cyclists.

Dietary obesity and neonatal sympathectomy. II. Thermoregulation and brown adipose metabolism

1984 ◽  
Vol 247 (6) ◽  
pp. R988-R994
Author(s):  
B. E. Levin ◽  
A. C. Sullivan
Keyword(s):  
Body Weight ◽  
Body Weight Gain ◽  
Plasma Norepinephrine ◽  
Plasma Catecholamine ◽  
O2 Consumption ◽  
Interscapular Brown Adipose Tissue ◽  
Insulin Levels ◽  
Brown Adipose ◽  
Obese Rats ◽  
Neonatal Sympathectomy

Neonatal sympathectomy with guanethidine (50 mg/kg for 3 wk) in Sprague-Dawley rats was previously shown not to significantly affect body weight gain, even when rats were raised in small litters and fed a high-calorie diet from weaning to produce diet-induced obesity (15). In our study rectal temperatures of cold-stressed (24 h at 4 degrees C) sympathectomized rats (obese and lean) fell only 1.4 degrees C after 4 h and were normal by 24 h, as were plasma catecholamine, glycerol glucose, and insulin levels after 4 h at 4 degrees C. Obese rats (with or without sympathectomy) had decreased 4-h (at 4 degrees C) plasma norepinephrine (NE) and increased basal and 4-h plasma glycerol, glucose, and insulin levels. Despite greater than 95% depletion of interscapular brown adipose tissue (IBAT) NE in sympathectomized rats, there was no alteration in beta-adrenoreceptor binding and only 10 and 32% decreases in basal and maximal NE-stimulated O2 consumption, respectively. Obese rats had significant increases in IBAT beta-receptor binding (148–190%/cell, 77–155%/pad) and in basal (11–19%) but not maximal O2 consumption. These results suggest that factors other than the sympathetic nervous system can effectively control thermoregulation, IBAT metabolism, and body weight in the presence of a chronic defect in sympathetic function.

Exercise metabolism at different time intervals after a meal

1991 ◽  
Vol 70 (2) ◽  
pp. 882-888 ◽  
Author(s):  
S. J. Montain ◽  
M. K. Hopper ◽  
A. R. Coggan ◽  
E. F. Coyle
Keyword(s):  
Plasma Glucose ◽  
Glucose Concentration ◽  
Respiratory Exchange Ratio ◽  
Metabolic Response ◽  
Plasma Glucose Concentration ◽  
Glycerol Concentration ◽  
O2 Consumption ◽  
Time Intervals ◽  
Trained Subjects ◽  
Response To Exercise

To determine how long a meal will affect the metabolic response to exercise, nine endurance-trained and nine untrained subjects cycled for 30 min at 70% of peak O2 consumption (VO2 peak) 2, 4, 6, 8, and 12 h after eating 2 g carbohydrate/kg body wt. In addition, each subject completed 30 min of cycling 4 h after the meal at an intensity that elicited a respiratory exchange ratio (RER) of 0.94-0.95. During exercise after 2 and 4 h of fasting, carbohydrate oxidation was elevated 13-15% compared with the response to exercise after an 8- and 12-h fast (P less than 0.01). The increase in blood glycerol concentration during exercise (30 to 0 min) was linearly related to the length of fasting (r = 0.99; P less than 0.01). In all subjects, plasma glucose concentration declined 17-21% during exercise after 2 h of fasting (P less than 0.01). Plasma glucose concentration also declined (15-25%) during exercise in the trained subjects after 4 and 6 h of fasting (P less than 0.05) but did not change in the untrained subjects. However, the decline in plasma glucose concentration was similar (14%) in the two groups when the exercise intensity was increased in the trained subjects (i.e., 78 +/- 1% VO2 peak) and decreased in the untrained subjects (i.e., 65 +/- 3% VO2 peak) to elicit a similar RER.(ABSTRACT TRUNCATED AT 250 WORDS)

Hypoxic potentiation of the ventilatory response to dynamic forearm exercise

1993 ◽  
Vol 74 (5) ◽  
pp. 2365-2372 ◽  
Author(s):  
R. F. Fregosi ◽  
D. R. Seals
Keyword(s):  
Ventilatory Response ◽  
Respiratory Drive ◽  
O2 Consumption ◽  
Exercise Tests ◽  
Systemic Hypoxia ◽  
Afferent Nerve Endings ◽  
Forearm Exercise ◽  
Response To Exercise ◽  
The Relationship ◽  
Stimulation Of

The slope of the relationship between ventilation (VI) and O2 consumption, as derived in progressive-intensity exercise tests, is increased markedly by systemic hypoxia. The mechanisms underlying the hypoxic potentiation of the ventilatory response to exercise have not been established, partly because several factors that can increase respiratory drive (e.g., metabolic rate, cardiac output, circulating catecholamine levels) change significantly and simultaneously under these conditions. In an effort to avoid these confounding changes, we sought to determine whether hypoxia potentiates the ventilatory response to dynamic forearm exercise in humans. Forearm exercise increased the O2 consumption by only 80–90 ml/min; nevertheless, hypoxia resulted in a significant potentiation of VI that was mediated by a marked increase in breathing frequency. These observations led us to hypothesize that the hypoxic potentiation of VI is due to an exaggerated stimulation of chemosensitive afferent nerve endings within the exercising muscles ("muscle chemoreceptors"). We tested this hypothesis in separate experiments under conditions of forearm ischemia so that the stimulus to the muscle chemoreceptors in normoxic and hypoxic exercise would be the same. The magnitude of the change in VI evoked by hypoxic ischemic exercise was significantly greater than the sum of the separate changes evoked by normoxic ischemic exercise and hypoxic ischemic rest. We conclude that the combination of dynamic forearm exercise and hypoxia potentiates VI and that this effect is mediated by neural structures that govern respiratory frequency. Moreover the potentiated ventilatory response cannot be attributed to an exaggerated stimulation of intramuscular chemoreceptors.

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