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Follow-up response of epinephrine and norepinephrine to an exhausting physical activity
Abstract
Catecholamines play an important role in a number of bodily functions such as metabolism of carbohydrates and lipids. Any change in the quantity of the hormones has negative effect on the performance of athletes. Fourteen young athletes participated in this study. The participants took Bruce Test with an average of 16.05 minutes and were totally exhausted. Four blood samples were taken. The results of the sample tests were analyzed by using paired sample t-test and repeated measures. The results showed that exhaustive aerobic exercises significantly increase Epinephrine (E) (P = 0.0001) and Norepinephrine (NE) (P = 0.01). The results also showed that the increase for norepinephrine continued two days after physical exercise. It seems that Catecholamines react differently to physical exercises and might be influenced by the psychological state of the athlete before the exercise and the duration and intensity of the exercise.
... It seems as if these trainings increase secretion of Catecholamine and sympathetic nerves' activity and decrease insulin secretion resulting in increase in growth hormones, cortisol, epinephrine and glucagon. Finally, this provides the ground for freeing fatty acids from fatty tissues (Shahsavar et al., 2011 and Poorveghar, 2014). ...
ABSTRACT
This modern age is experiencing increased cardiovascular diseases and higher mortality rates due to inert lifestyles and bad nutrition habits along with stress. Apo lipoproteins A and B are among the most important prognosticating factors of cardiac diseases. Therefore, the present study attempts to study the effects of a three-month college football practice on changes in Apo proteins A and B in inactive young men. Through a public call, 30 subjects were selected randomly from male college students and were divided into two control and experimental groups of 15. The experimental group participated in 3 sessions of exercising per week and the control group had not practice at all. 24 hours before the first and 24 hours after the last exercise session, 10 cc blood samples were taken from both groups after 12 hours of fasting from the left arm vessel. These samples were centrifuged to separate the serum and kept at -70° c to be analyzed at a laboratory. In order to compare Apo proteins A and B of the posttest in both groups, covariance analysis was utilized. Results revealed that physical activities in the form of three-month college football practice change Apo protein A and B levels in blood serum in pre and posttests of experimental group significantly. Yet, the study failed to find significant differences in the level of Apo protein A and B of control and experimental groups.
Key words: College football; Apo protein A; Apo protein B; Young men; Inactive
Four untrained standardbred horses performed a standardized exercise test on the treadmill and an automated blood collection system programmed to obtain blood samples every 15 s was used for blood collection in order to evaluate the kinetics of adrenaline and noradrenaline. The highest average values obtained for adrenaline and noradrenaline were 15.0 +/- 3.0 and 15.8 +/- 2.8 nmol/l respectively, with exponential accumulation of adrenaline (r = 0.977) and noradrenaline (r = 0.976) during the test. Analysis of the correlation between noradrenaline and adrenaline for each phase of the test shows that correlation coefficient decreases as the intensity of exercise increases (from r = 0.909 to r = 0.788). This suggests that during submaximal exercise, the process for release, distribution and clearance of adrenaline into blood circulation differs from that of noradrenaline.
The purpose of this study was to investigate the effect of the level of injury on the serum level of norepinephrine (Nor) and epinephrine (Epi) at rest and after maximal exercise in individuals with paraplegia. Twenty-six male spinal cord-injured subjects with complete paraplegia for at least 9 months were divided into two groups of 13 subjects each according to the level of injury, i.e., T1-T6 and T7-T12. Serum Nor and Epi concentrations were measured by HPLC-ECD, at rest (PRE) and immediately after a maximal ergospirometric test (POST). Statistical analysis was performed using parametric and non-parametric tests. Maximal heart rate, peak oxygen uptake, and PRE and POST Nor were lower in the T1-T6 than in the T7-T12 group (166 +/- 28 vs 188 +/- 10 bpm; 18.0 +/- 6.0 vs 25.8 +/- 4.1 ml kg(-1) min(-1); 0.54 +/- 0.26 vs 0.99 +/- 0.47 nM; 1.48 +/- 1. 65 vs 3.07 +/- 1.44 nM). Both groups presented a significant increase in Nor level after exercise, while only the T7-T12 group showed a significant increase in Epi after exercise (T1-T6: 0.98 +/- 0.72 vs 1.11 +/- 1.19 nM; T7-T12: 1.24 +/- 1.02 vs 1.89 +/- 1.57 nM). These data show that individuals with paraplegia above T6 have an attentuated catecholamine release at rest and response to exercise as compared to subjects with injuries below T6, which might prevent a better exercise performance in the former group.
The adrenaline release from the adrenal medulla increases during exercise, but at a given absolute work intensity the magnitude of this response is less pronounced in endurance trained vs sedentary individuals most likely due to a lower sympathetic stimulation of the adrenal medulla. However, when trained and untrained subjects are compared at identical relative work loads as well as in response to numerous non-exercise stimuli. endurance trained athletes have a higher epinephrine secretion capacity compared to sedentary individuals. This indicates a development of a so-called "sports adrenal medulla" as a result of a long term adaptation of an endocrine gland to physical training. Such an adaptation is parallel to adaptations taking place in other tissues like skeletal muscle and the heart. and can be advantageous in relation to both exercise performance in the competing athlete and cause a biological rejuvenation in relation to aging.
The purpose of this study was to determine the effect of increasing muscle mass involvement in dynamic exercise on both sympathetic nervous activation and local hemodynamic variables of individual active and inactive skeletal muscle groups. Six male subjects performed 15-min bouts of one-legged knee extension either alone or in combination with the knee extensors of the other leg and/or with the arms. The range of work intensities varied between 24 and 71% (mean) of subjects' maximal aerobic capacity (% VO2max). Leg blood flow, measured in the femoral vein by thermodilution, was determined in both legs. Arterial and venous plasma concentrations of norepinephrine (NE) and epinephrine were analyzed, and the calculated NE spillover was used as an index of sympathetic nervous activity to the limb. NE spillover increased gradually both in the resting, and to a larger extent in the exercising legs, with a steeper rise occurring approximately 70% VO2max. These increases were not associated with any significant changes in leg blood flow or leg vascular conductance at the exercise intensities examined. These results suggest that, as the total active muscle mass increases, the rise in sympathetic nervous activity to skeletal muscle, either resting or working at a constant load, is not associated with any significant neurogenic vasoconstriction and reduction in flow or conductance through the muscle vascular bed, during whole body exercise demanding up to 71% VO2max.
The purpose of this study was to compare the adrenal medullar responsiveness to the sympathetic nervous activity between sprinters and untrained subjects after a supramaximal exercise (Wingate-test). Thirteen subjects took part in this study: 7 male athletes (20.3+/-1.8 years) competing in sprint running (S) and 6 untrained men (UT) (21+/-1.3 years). They performed an incremental treadmill test to determine the maximal oxygen uptake (VO2max), a force-velocity test and a Wingate-test on 3 different days, separated by a maximal interval of 15 days. The maximal power (Wmax) and the mean power (W) were determined from the Wingate-test on a cycle ergometer. Plasma lactate, adrenaline and noradrenaline concentrations were determined at rest (La0, A0, NA0), immediately after the Wingate-test (Amax, NAmax) and after 5 minutes recovery (Lamax, A5 and NA5). S exhibited higher performances than UT during the Wingate-test as shown by their significantly higher values of Wmax (1111+/-38 w in S vs 886+/-148 w in UT), W (822+/-37 w in S vs 646+/-69 w in UT) and Lamax (16.8+/1.8 mmol x l(-1) in S vs 12.2+/-2.5 mmol x l(-1) in UT). At the end of the test the NAmax values were similar in both groups whereas the Amax were significantly higher in S (7.6 +/- 1.4 nmol x l(-1) in S vs 3.6 +/- 3.2 nmol x l(-1) in UT). This leads to a higher Amax/NAmax ratio for sprinters compared to untrained subjects (0.7+/-0.2 in S vs 0.3+/-0.2 in UT, p < 0.05). As the disappearance of A (estimated by the Amax-A5 difference) was not lower in S (6.4+/1.5 nmol x l(-1) in S vs 1.8+/-4 nmol x l(-1) in UT), the higher Amax values in S might be explained by a greater secretion level of A. Conversely the identical NAmax values in both groups suggested that this kind of exercise induced the same sympathetic input in S and UT. Consequently the higher Amax/NAmax ratio in S argued in favor of a higher responsiveness of the adrenal medulla of sprinters to the same sympathetic input.
We have explored in the following study the glucoregulatory responses (glycemia, insulinemia, catecholamines) at the end of 2 supramaximal tests of different durations.
Seven untrained male subjects (21.9+/-0.3 y) performed an isolated exercise of 6 s (T6) and a Wingate-test of 30 s. To determine the levels of lactate (La), plasma concentrations of glucose, insulin, adrenaline (A) and noradrenaline (NA), blood samples have been collected successively at rest, after a warm-up period of 15 min, immediately after T6 and T30, and after 5, 10, 20, and 30 min of recovery.
Whether expressed as absolute or relative values, the peak power recorded during the 2 tests is statistically the same in T6 and T30. The maximal value of lactate (L(amax)) measured 5 min after the end of the 2 exercises is significantly greater after T30 (12.3+/-0.9 mmol x L(-1)) than after T6 (5.4+/-0.4 mmol x L(-1)) and T30 (4.2+/-0.2 mmol x L(-1)). No significant difference is observed between the plasma glucose concentrations recorded after the 2 tests until the first 10 min of recovery. However the plasma glucose values recorded after 20 and 30 min of recovery are significantly higher after T6 than after T30. Whatever the duration of the test, the insulinemia level remains unchanged at the end of the exercise and during the 30 min of recovery. On the other hand, the values of adrenaline and noradrenaline after T6 and T30 become considerably higher than those recorded at rest. However, the increase remains significantly higher after T30 (13.5+/-1.8 nmol x L(-1) for NA and 2.7+/-0.7 nmol x L(-1) for A) than after T6 (4.9+/-0.3 nmol x L(-1) for NA and 1.2+/-0.2 nmol x L(-1) for A).
These results suggest that the mechanism responsible for increasing blood glucose surpass those which decrease it during supramaximal exercise. However, plasma glucose concentrations is affected by the duration of supramaximal exercise. The lower increase of plasma glucose concentration after T30 than after T6 might be explained by the resting of muscle glycogen stores which are more used during T30 than after T6, but in the absence of muscle glycogen content measurement we cannot conclude.