Effect of acute hypoxia on the hormonal response to exercise

1977 ◽  
Vol 42 (4) ◽  
pp. 587-592 ◽  
Author(s):  
J. R. Sutton
Keyword(s):  
Serum Insulin ◽  
Acute Hypoxia ◽  
Venous Blood ◽  
Cycle Ergometer ◽  
Serum Growth Hormone ◽  
Hormonal Responses ◽  
Hypoxic Conditions ◽  
Fat Mobilization ◽  
Response To Exercise ◽  
Hypoxic Exercise

The hormonal responses to submaximal exercise under normoxic and hypoxic conditions were studied in eight fit males, aged 22--28 yr, with mean maximal oxygen uptake of 4.4 +/- 0.7 l/min. Studies were performed in a hypobaric chamber, decompressed to a simulated altitude of 4,550 m (PIO2 = 83 Torr). The subjects exercised for 20 min at 750 kpm/min on a cycle ergometer. Venous blood samples were obtained at rest, during exercise and for 60 min after exercise. Plasma glucose, free fatty acids, lactate, cortisol, and serum growth hormone concentrations all increased more during hypoxic exercise than under normoxic conditions. Serum insulin concentration showed a small decrease under normoxic conditions, but decreased by 50% during hypoxic exercise, and was followed by marked rebound when exercise stopped. These changes suggest that energy substrate-hormone interrelationships are altered by hypoxic exercise, resulting in increased fat mobilization and increased gluconeogenesis.

Opioid antagonism alters blood glucose homeostasis during exercise in humans

1994 ◽  
Vol 76 (6) ◽  
pp. 2452-2460 ◽  
Author(s):  
M. S. Hickey ◽  
S. W. Trappe ◽  
A. C. Blostein ◽  
B. A. Edwards ◽  
B. Goodpaster ◽  
...  
Keyword(s):  
Serum Insulin ◽  
Insulin Response ◽  
Serum Glucose ◽  
Endogenous Opioid ◽  
Hormonal Responses ◽  
Blood Glucose Homeostasis ◽  
The Difference ◽  
Response To Exercise ◽  
Exercise In Humans

In an attempt to clarify the role of endogenous opioid peptides in substrate mobilization and hormonal responses to dynamic exercise, eight trained cyclists completed exercise trials at 90% of maximal O2 consumption (VO2max) until exhaustion and at 70% VO2max for 90 min. Trials were conducted after intravenous administration of the opiate antagonist naloxone (NAL, 0.1 mg/kg bolus + 0.1 mg.kg-1.h-1) or volume-matched saline (SAL) at each intensity. Serum glucose was maintained at significantly higher levels at 60 and 90 min of exercise in the 70%-NAL than in the 70%-SAL trial and at all points during exercise and at 30 and 60 min of recovery in the 90%-NAL than in the 90%-SAL trial. The serum insulin response to exercise was not altered by NAL administration at either intensity. Serum C-peptide was approximately 50% higher at 60 and 90 min of exercise in the 70%-NAL than in the 70%-SAL trial but was significantly lower during exercise in the 90%-NAL than in the 90%-SAL trial. The plasma glucagon response to exercise at 70% VO2max was not altered by NAL administration but was significantly elevated in the 90%-NAL vs. the 90%-SAL trial. Plasma epinephrine was 50–150% (approximately 2–3 nM) higher during exercise from 30 to 90 min of exercise in the 70%-NAL than in the 70%-SAL trial and was higher at termination (4.9 +/- 2.1 vs. 2.7 +/- 1.7 nM) in the 90%-NAL than in the 90%-SAL trial, although the difference in the 90% trial was not statistically significant.(ABSTRACT TRUNCATED AT 250 WORDS)

Aldosterone and prolactin response to exercise in the heat in circumpubertal boys

1991 ◽  
Vol 71 (5) ◽  
pp. 1741-1745 ◽  
Author(s):  
B. Falk ◽  
O. Bar-Or ◽  
J. D. MacDougall
Keyword(s):  
Venous Blood ◽  
Plasma Osmolality ◽  
O2 Uptake ◽  
Hormonal Responses ◽  
Tanner Staging ◽  
Water Ingestion ◽  
Physical Maturation ◽  
Prolactin Response ◽  
Response To Exercise ◽  
Percent Decrease

Thermoregulatory responses to exercise in the heat, especially sweating pattern, differ between children and adults. To determine whether such differences may be related to hormonal responses and to assess the possible association between this response and physical maturation, three groups of circumpubertal boys cycled at 50% of maximal O2 uptake (three 20-min bouts with 10 min of rest between bouts) in 42 degrees C at 20% relative humidity. On the basis of Tanner staging, 11 were prepubertal (PP), 12 midpubertal (MP), and 7 late pubertal (LP). Water ingestion was encouraged to minimize dehydration. Venous blood was sampled before and immediately after the session. Changes in heart rate, rectal temperature, and percent decrease in plasma volume did not differ among groups. There was no change in plasma osmolality in any of the groups. Resting testosterone concentrations were higher with increased level of physical maturity (PP = 0.4 +/- 0.1, MP = 8.2 +/- 1.9, LP = 13.8 +/- 1.2 nmol/l; P less than 0.05). In all groups, both aldosterone (ALD) and prolactin (PRL) markedly increased after exercise in the heat (ALD: PP = 161 +/- 40 vs. 1,289 +/- 263, MP = 173 +/- 47 vs. 1,245 +/- 153, LP = 250 +/- 76 vs. 1,681 +/- 400 pmol/l; PRL: PP = 8.1 +/- 1.2 vs. 24.9 +/- 4.2, MP = 8.8 +/- 1.0 vs. 22.0 +/- 8.9, LP = 8.4 +/- 0.8 vs. 39.0 +/- 3.6 micrograms/l; P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Hypoxia augments muscle sympathetic neural response to leg cycling

2011 ◽  
Vol 301 (2) ◽  
pp. R456-R464 ◽  
Author(s):  
Keisho Katayama ◽  
Koji Ishida ◽  
Erika Iwamoto ◽  
Motoyuki Iemitsu ◽  
Teruhiko Koike ◽  
...  
Keyword(s):  
Muscle Sympathetic Nerve Activity ◽  
Acute Hypoxia ◽  
Venous Blood ◽  
Peak Oxygen Uptake ◽  
Cycle Ergometer ◽  
Submaximal Exercise ◽  
Plasma Norepinephrine ◽  
Neural Activation ◽  
Exercise Tests ◽  
Leg Exercise

It was demonstrated that acute hypoxia increased muscle sympathetic nerve activity (MSNA) by using a microneurographic method at rest, but its effects on dynamic leg exercise are unclear. The purpose of this study was to clarify changes in MSNA during dynamic leg exercise in hypoxia. To estimate peak oxygen uptake (V̇o2 peak), two maximal exercise tests were conducted using a cycle ergometer in a semirecumbent position in normoxia [inspired oxygen fraction (FiO2) = 0.209] and hypoxia (FiO2 = 0.127). The subjects performed four submaximal exercise tests; two were MSNA trials in normoxia and hypoxia, and two were hematological trials under each condition. In the submaximal exercise test, the subjects completed two 15-min exercises at 40% and 60% of their individual V̇o2 peak in normoxia and hypoxia. During the MSNA trials, MSNA was recorded via microneurography of the right median nerve at the elbow. During the hematological trials, the subjects performed the same exercise protocol as during the MSNA trials, but venous blood samples were obtained from the antecubital vein to assess plasma norepinephrine (NE) concentrations. MSNA increased at 40% V̇o2 peak exercise in hypoxia, but not in normoxia. Plasma NE concentrations did not increase at 40% V̇o2 peak exercise in hypoxia. MSNA at 40% and 60% V̇o2 peak exercise were higher in hypoxia than in normoxia. These results suggest that acute hypoxia augments muscle sympathetic neural activation during dynamic leg exercise at mild and moderate intensities. They also suggest that the MSNA response during dynamic exercise in hypoxia could be different from the change in plasma NE concentrations.

scholarly journals Exercise-Induced Elevated BDNF Level Does Not Prevent Cognitive Impairment Due to Acute Exposure to Moderate Hypoxia in Well-Trained Athletes

2020 ◽  
Vol 21 (15) ◽  
pp. 5569 ◽  
Author(s):  
Zofia Piotrowicz ◽  
Małgorzata Chalimoniuk ◽  
Kamila Płoszczyca ◽  
Miłosz Czuba ◽  
Józef Langfort
Keyword(s):  
Acute Hypoxia ◽  
Negative Effects ◽  
Positive Effects ◽  
Hypoxic Conditions ◽  
Acute Elevation ◽  
Psychomotor Tasks ◽  
Exercise Induced ◽  
Response To Exercise ◽  
Cognition Impairment ◽  
The Brain

Exposure to acute hypoxia causes a detrimental effect on the brain which is also manifested by a decrease in the ability to perform psychomotor tasks. Conversely, brain-derived neurotrophic factor (BDNF), whose levels are elevated in response to exercise, is a well-known factor in improving cognitive function. Therefore, the aim of our study was to investigate whether the exercise under hypoxic conditions affects psychomotor performance. For this purpose, 11 healthy young athletes performed a graded cycloergometer exercise test to volitional exhaustion under normoxia and acute mild hypoxia (FiO2 = 14.7%). Before, immediately after exercise and after a period of recovery, choice reaction time (CRT) and number of correct reactions (NCR) in relation to changes in serum BDNF were examined. Additionally, other selected factors which may modify BDNF production, i.e., cortisol (C), nitrite, catecholamines (adrenalin-A, noradrenaline-NA, dopamine-DA, serotonin-5-HT) and endothelin-1 (ET-1), were also measured. Exercise in hypoxic conditions extended CRT by 13.8% (p < 0.01) and decreased NCR (by 11.5%) compared to rest (p < 0.05). During maximal workload, NCR was lower by 9% in hypoxia compared to normoxia (p < 0.05). BDNF increased immediately after exercise in normoxia (by 29.3%; p < 0.01), as well as in hypoxia (by 50.0%; p < 0.001). There were no differences in BDNF between normoxia and hypoxia. Considering the fact that similar levels of BDNF were seen in both conditions but cognitive performance was suppressed in hypoxia, acute elevation of BDNF did not compensate for hypoxia-induced cognition impairment. Moreover, neither potentially negative effects of C nor positive effects of A, DA and NO on the brain were observed in our study.

The Effect of Moderate Exercise on Blood Metabolites in Patients with Hypopituitarism

1971 ◽  
Vol 40 (2) ◽  
pp. 127-136 ◽  
Author(s):  
R. H. Johnson ◽  
M. J. Rennie ◽  
J. L. Walton ◽  
M. H. C. Webster
Keyword(s):  
Growth Hormone ◽  
Ketone Bodies ◽  
Venous Blood ◽  
Normal Subjects ◽  
Bicycle Ergometer ◽  
Blood Metabolites ◽  
Serum Growth Hormone ◽  
Post Exercise ◽  
Blood Samples ◽  
Fat Mobilization

1. Six patients with panhypopituitarism and eight controls were studied before, during and after 30 min of moderate, steady exercise on a bicycle ergometer. Venous blood samples were taken for estimation of growth hormone, pyruvate, lactate, glucose, FFA, glycerol and ketone bodies. 2. Exercise caused a rise in serum growth hormone levels in control subjects and these fell to pre-exercise levels within 90 min. There was no change in the levels in the patients. The patients showed changes in blood metabolites resembling those of the controls. FFA levels were considerably elevated and post-exercise ketosis developed, these changes being more marked in the patients. 3. The differences in FFA and ketone bodies between patients and controls may be due to the lower levels of fitness in the patients. A further explanation may be that growth hormone depresses FFA levels after initial mobilization during exercise in normal subjects, but no such action can occur in patients with hypopituitarism. 4. It is concluded that growth hormone does not necessarily have a major role in fat mobilization or in the production of post-exercise ketosis. Thus, the lower levels of ketosis observed in athletes are not due to their lower levels of growth hormone.

Investigation of the Association Between Carotid Artery Intima-Media Thickness (IMT) and Cardiac Risk Factors in Patients with Systemic Lupus Erythematosus

2020 ◽  
Vol 16 (2) ◽  
pp. 125-133
Author(s):  
Zahra Rezaieyazdi ◽  
Sima Sedighi ◽  
Masoumeh Salari ◽  
Mohammadreza H. Fard ◽  
Mahmoud R. Azarpazhooh ◽  
...  
Keyword(s):  
Risk Factors ◽  
Insulin Resistance ◽  
Lupus Erythematosus ◽  
Serum Insulin ◽  
Venous Blood ◽  
Test Group ◽  
Control Groups ◽  
Significant Difference ◽  
The Mean ◽  
And Control

Background: The relationship between SLE and traditional risk factors for cardiovascular events was evaluated. Methods: The data regarding sixty patients with SLE and 30 healthy controls (age and sex matched) were gathered using SLEDAI forms. Venous blood (10mL) from all the participants was examined for hs-CRP, homocysteine, VCAM1, CBC, anti-DNA antibody, C3, C4, low-density lipoprotein (LDL), cholesterol, FBS and triglyceride. : The IMT of carotid arteries was determined bilaterally by ultrasound. Other measurements included insulin levels via Elisa (Linco/Millipore Corp) and the HOMA-IR index for insulin resistance. Results: The mean age (in years) in the test and control groups was 28.8±10.3 (18-52) and 33.8±9.13 (18-48), respectively. Results: The mean age (in years) in the test and control groups was 28.8±10.3 (18-52) and 33.8±9.13 (18-48), respectively. : The average IMT in the test group was directly related to serum levels of VCAM1 (p<0.001), homocysteine (p<0.001), cholesterol (p<0.009), LDL (p<0.001), TG (p<0.001), and FPG (p=0.004). The association between other risk factors, insulin resistance, carotid IMT and SLEDAI, was nonexistent. Mean insulin and insulin resistance levels in all the participants were 0.43±2.06 µU/mL and 0.09±0.44, respectively. There was no significant difference between the test and control groups regarding serum insulin and insulin resistance levels (p=0.42 and p=0.9, respectively). None of the risk factors, such as hsCRP, VCAM1, or homocysteine, were shown to be related to insulin resistance (p=0.6, p=0.6, p=0.09, respectively). Conclusion:: Our findings did not show an increase in the prevalence of atherosclerosis in patients with SLE. There was no association between IMT and insulin resistance. However, the former was associated with FPG, total cholesterol, LDL, TG, homocystein and VCAM1.

scholarly journals Spleen contraction elevates hemoglobin concentration at high altitude during rest and exercise

2020 ◽  
Vol 120 (12) ◽  
pp. 2693-2704
Author(s):  
Erika Schagatay ◽  
Alexander Lunde ◽  
Simon Nilsson ◽  
Oscar Palm ◽  
Angelica Lodin-Sundström
Keyword(s):  
High Altitude ◽  
Acute Hypoxia ◽  
Arterial Oxygen Saturation ◽  
Hemoglobin Concentration ◽  
Step Test ◽  
Arterial Oxygen ◽  
Spleen Volume ◽  
Spleen Contraction ◽  
Response To Exercise ◽  
Rest And Exercise

Abstract Purpose Hypoxia and exercise are known to separately trigger spleen contraction, leading to release of stored erythrocytes. We studied spleen volume and hemoglobin concentration (Hb) during rest and exercise at three altitudes. Methods Eleven healthy lowlanders did a 5-min modified Harvard step test at 1370, 3700 and 4200 m altitude. Spleen volume was measured via ultrasonic imaging and capillary Hb with Hemocue during rest and after the step test, and arterial oxygen saturation (SaO2), heart rate (HR), expiratory CO2 (ETCO2) and respiratory rate (RR) across the test. Results Resting spleen volume was reduced with increasing altitude and further reduced with exercise at all altitudes. Mean (SE) baseline spleen volume at 1370 m was 252 (20) mL and after exercise, it was 199 (15) mL (P < 0.01). At 3700 m, baseline spleen volume was 231 (22) mL and after exercise 166 (12) mL (P < 0.05). At 4200 m baseline volume was 210 (23) mL and after exercise 172 (20) mL (P < 0.05). After 10 min, spleen volume increased to baseline at all altitudes (NS). Baseline Hb increased with altitude from 138.9 (6.1) g/L at 1370 m, to 141.2 (4.1) at 3700 m and 152.4 (4.0) at 4200 m (P < 0.01). At all altitudes Hb increased from baseline during exercise to 146.8 (5.7) g/L at 1370 m, 150.4 (3.8) g/L at 3700 m and 157.3 (3.8) g/L at 4200 m (all P < 0.05 from baseline). Hb had returned to baseline after 10 min rest at all altitudes (NS). The spleen-derived Hb elevation during exercise was smaller at 4200 m compared to 3700 m (P < 0.05). Cardiorespiratory variables were also affected by altitude during both rest and exercise. Conclusions The spleen contracts and mobilizes stored red blood cells during rest at high altitude and contracts further during exercise, to increase oxygen delivery to tissues during acute hypoxia. The attenuated Hb response to exercise at the highest altitude is likely due to the greater recruitment of the spleen reserve during rest, and that maximal spleen contraction is reached with exercise.

scholarly journals Hypoxia Transcriptomic Modifications Induced by Proton Irradiation in U87 Glioblastoma Multiforme Cell Line

2021 ◽  
Vol 11 (4) ◽  
pp. 308
Author(s):  
Valentina Bravatà ◽  
Walter Tinganelli ◽  
Francesco P. Cammarata ◽  
Luigi Minafra ◽  
Marco Calvaruso ◽  
...  
Keyword(s):  
Glioblastoma Multiforme ◽  
Cell Line ◽  
Acute Hypoxia ◽  
Hypoxic Condition ◽  
Biological Processes ◽  
Microarray Gene Expression ◽  
Hypoxic Conditions ◽  
Gene Expression Analyses ◽  
Shed Light ◽  
New Strategies

In Glioblastoma Multiforme (GBM), hypoxia is associated with radioresistance and poor prognosis. Since standard GBM treatments are not always effective, new strategies are needed to overcome resistance to therapeutic treatments, including radiotherapy (RT). Our study aims to shed light on the biomarker network involved in a hypoxic (0.2% oxygen) GBM cell line that is radioresistant after proton therapy (PT). For cultivating cells in acute hypoxia, GSI’s hypoxic chambers were used. Cells were irradiated in the middle of a spread-out Bragg peak with increasing PT doses to verify the greater radioresistance in hypoxic conditions. Whole-genome cDNA microarray gene expression analyses were performed for samples treated with 2 and 10 Gy to highlight biological processes activated in GBM following PT in the hypoxic condition. We describe cell survival response and significant deregulated pathways responsible for the cell death/survival balance and gene signatures linked to the PT/hypoxia configurations assayed. Highlighting the molecular pathways involved in GBM resistance following hypoxia and ionizing radiation (IR), this work could suggest new molecular targets, allowing the development of targeted drugs to be suggested in association with PT.

scholarly journals Aerobic and anaerobic metabolism for the zebrafish, Danio rerio, reared under normoxic and hypoxic conditions and exposed to acute hypoxia during development

2010 ◽  
Vol 70 (2) ◽  
pp. 425-434 ◽  
Author(s):  
WR Barrionuevo ◽  
MN Fernandes ◽  
O Rocha
Keyword(s):  
Danio Rerio ◽  
Anaerobic Metabolism ◽  
Developmental Stages ◽  
Acute Hypoxia ◽  
Lactate Concentration ◽  
Growth Delay ◽  
Hypoxic Conditions ◽  
Aerobic And Anaerobic ◽  
Mild Hypoxia

In order to verify the influence of chronic and acute ambient oxygen levels from egg to adult stage of the zebrafish, in vivo oxygen consumption (MO2), critical tensions of oxygen (Pcrit), heart rate (fH) and total body lactate concentration (Lc) were determined for Danio rerio (Hamilton, 1822) raised at 28 °C under normoxic (7.5 mgO2.L-1 or 80 mm.Hg-1) and hypoxic conditions (4.3 mgO2.L-1) and exposed to acute hypoxia during different developmental stages. Our findings confirmed that very early stages do not respond effectively to ambient acute hypoxia. However, after the stage corresponding to the age of 30 days, D. rerio was able to respond to acute hypoxia through effective physiological mechanisms involving aerobic and anaerobic metabolism. Such responses were more efficient for the fishes reared under hypoxia which showed that D. rerio survival capability increased during acclimation to mild hypoxia. Measurements of body mass and length showed that moderate hypoxia did not affect growth significantly until the fish reached the stage of 60 days. Moreover, a growth delay was verified for the hypoxic-reared animals. Also, the D. rerio eggs-to-larvae survival varied from 87.7 to 62.4% in animals reared under normoxia and mild hypoxia, respectively. However, the surviving animals raised under moderated hypoxia showed a better aptitude to regulate aerobic and anaerobic capacities when exposed to acute hypoxia.

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