scholarly journals Plasma 2-hydroxycatecholestrogen responses to acute submaximal and maximal exercise in untrained women

1997 ◽  
Vol 82 (1) ◽  
pp. 364-370 ◽  
Author(s):  
Carl De Crée ◽  
Peter Ball ◽  
Bärbel Seidlitz ◽  
Gerrit Van Kranenburg ◽  
Peter Geurten ◽  
...  

De Crée, Carl, Peter Ball, Bärbel Seidlitz, Gerrit Van Kranenburg, Peter Geurten, and Hans A. Keizer. Plasma 2-hydroxycatecholestrogen responses to acute submaximal and maximal exercise in untrained women. J. Appl. Physiol. 82(1): 364–370, 1997.—Exercise-induced menstrual problems are accompanied by an increase in catecholestrogen (CE) formation. It has been hypothesized that hypoestrogenemia may be secondary to an increased turnover from estrogens to CE, which then may disrupt luteinizing hormone release. In addition, the strong affinity of CE for the catecholamine-deactivating enzyme catechol- O-methyltransferase (COMT) has led to speculations about their possible role in safeguarding norepinephrine from premature decomposition during exercise. We investigated whether acute exercise on a cycle ergometer produces any changes in CE homeostasis. Nine untrained eumenorrheic women (body fat, 24.8 ± 3.1%) volunteered for this study. Baseline plasma CE averages for total 2-hydroxyestrogens (2-OHE) were 218 ± 29 (SE) pg/ml during the follicular phase (FPh) and 420 ± 58 pg/ml during the luteal phase (LPh). 2-Methoxyestrogens (2-MeOE) measured 257 ± 17 pg/ml in the FPh and 339 ± 39 pg/ml in the LPh. During incremental exercise, total estrogens (E) increased, but 2-OHE and 2-MeOE levels did not significantly change in either phase. The 2-OHE/E ratio (measure of CE turnover) decreased during exercise in both menstrual phases, whereas the 2-MeOE/2-OHE ratio (correlates with COMT activity) did not significantly change. These findings suggest that there is insufficient evidence to conclude that brief incremental exercise in untrained eumenorrheic females acutely produces increased CE formation.

2015 ◽  
Vol 93 (6) ◽  
pp. 413-419 ◽  
Author(s):  
David Opitz ◽  
Edward Lenzen ◽  
Andreas Opiolka ◽  
Melanie Redmann ◽  
Martin Hellmich ◽  
...  

Chronic elevated lactate levels are associated with insulin resistance in patients with type 2 diabetes mellitus (T2DM). Furthermore, lactacidosis plays a role in limiting physical performance. Erythrocytes, which take up lactate via monocarboxylate transporter (MCT) proteins, may help transport lactate within the blood from lactate-producing to lactate-consuming organs. This study investigates whether cycling endurance training (3 times/week for 3 months) alters the basal erythrocyte content of MCT-1, and whether it affects lactate distribution kinetics in the blood of T2DM men (n = 10, years = 61 ± 9, body mass index = 31 ± 3 kg/m2) following maximal exercise (WHO step-incremental cycle ergometer test). Immunohistochemical staining indicated that basal erythrocyte contents of MCT-1 protein were up-regulated (+90%, P = 0.011) post-training. Erythrocyte and plasma lactate increased from before acute exercise (= resting values) to physical exhaustion pre- as well as post-training (pre-training: +309%, P = 0.004; +360%, P < 0.001; post-training: +318%, P = 0.008; +300%, P < 0.001), and did not significantly decrease during 5 min recovery. The lactate ratio (erythrocytes:plasma) remained unchanged after acute exercise pre-training, but was significantly increased after 5 min recovery post-training (compared with the resting value) (+22%, P = 0.022). The results suggest an increased time-delayed influx of lactate into erythrocytes following an acute bout of exercise in endurance-trained diabetic men.


2008 ◽  
Vol 104 (1) ◽  
pp. 186-197 ◽  
Author(s):  
Richard M. McAllister ◽  
Sean C. Newcomer ◽  
Eric R. Pope ◽  
James R. Turk ◽  
M. Harold Laughlin

Nitric oxide (NO) is potentially involved in several responses to acute exercise. We tested the hypotheses that inhibition of NO formation reduces maximal O2 delivery to muscle, but does not affect O2 utilization by muscle, therefore lowering maximal O2 consumption. To test these hypotheses, swine (∼30 kg) drank either tap water (Con, n = 25) or water with NG-nitro-l-arginine methyl ester (8.0 ± 0.4 mg·kg−1·day−1 for ≥4 wk; LN, n = 24). Treatment efficacy was reflected by higher mean arterial pressure and lower plasma NO metabolite concentration in LN than Con (both P < 0.05). Swine completed two graded treadmill running tests to maximum. In the first test, O2 consumption was determined at rest through maximal exercise intensity. O2 consumption did not differ between groups at rest or at most exercise intensities, including maximum (Con, 40.8 ± 1.8 ml·min−1·kg−1; LN, 40.4 ± 2.9; not significant). In the second test, tissue-specific blood flows were determined using the radiolabeled-microsphere technique. At rest, blood flows were lower ( P < 0.05) in LN compared with Con for a number of tissues, including kidney, adrenal, lung, and several skeletal muscles. During both submaximal and maximal exercise, however, blood flows were similar between Con and LN for all 16 muscles examined; only blood flows to kidney (Con, 99 ± 16 ml·min−1·100 g; LN, 55 ± 15; P < 0.05) and pancreas (Con, 25 ± 7; LN, 6 ± 2; P < 0.05) were lower in LN at maximum. Endothelium-dependent, but not -independent, relaxation of renal arterial segments was reduced ( P < 0.05) in vitro. These data indicate that exercise-induced increases in muscle blood flows are maintained with chronic inhibition of NO formation and that maximal O2 consumption is therefore preserved. Redundant vasodilatory pathways and/or upregulation of these pathways may underlie these findings.


1986 ◽  
Vol 110 (1) ◽  
pp. 19-26 ◽  
Author(s):  
S. L. Alexander ◽  
C. H. G. Irvine

ABSTRACT Luteinizing hormone release induced by a range of small (3·3–33 μg) and large (300–500 μg) i.v. doses of gonadotrophin-releasing hormone (GnRH) was measured in acyclic (n = 4), luteal phase (n = 3) and follicular phase (n = 5) mares and compared with endogenously generated LH pulses in the same reproductive states. Extrapolation from log–linear dose–response curves showed that an LH pulse comparable to an endogenous one would be simulated by i.v. injection of 7·0 (n = 4) and 4·1 (n = 6) μg GnRH in luteal and follicular phase mares respectively; a much smaller dose than the 500 μg usually given clinically or experimentally. In acyclic mares (n = 4), LH pulses occurred too infrequently to be characterized. At small doses of GnRH the amount of LH released by the same dose was similar in all three reproductive states, although the steroid hormone milieu differed markedly. This implies that observed differences between states in mean (± s.e.m.) serum LH concentrations (0·7 ± 0·01, 1·2 ± 0·03 and 11·6 ± 0·33 (μg/l) in acyclic, luteal and follicular phase mares respectively) were produced by differences in GnRH pulse frequency and/or amplitude and not by steroid-mediated changes in pituitary response to GnRH. In acyclic, luteal and follicular phase mares, LH pulse frequency was: immeasurably low, 0·09 and 1·14 pulses/h respectively, which supports the important contribution of pulse frequency to determining mean LH concentration. The LH response to large doses of GnRH was significantly greater in the luteal than in the follicular phase, and was greater than the response to 33 μg in the luteal phase but not in the other two states. Thus, to a large but not to a small dose of GnRH, the pituitary appeared most responsive in the luteal phase. Therefore, in studies of the physiology of the hypothalamic-pituitary system, small doses of GnRH, which induce physiologically sized LH responses, may be preferred to large doses, which result in a level of stimulation to which the pituitary is never naturally exposed and to which it may respond in a non-physiological manner. J. Endocr. (1986) 110, 19–26


Author(s):  
Kelsey Elizabeth Joyce ◽  
George M. Balanos ◽  
Christopher Bradley ◽  
Amy Fountain ◽  
Arthur Randell Bradwell ◽  
...  

Introduction: Proteinuria is a transient physiologic phenomenon that occurs with a range of physical activities and during ascent to altitude. Exercise intensity appears to dictate the magnitude of post-exercise proteinuria; however, evidence also indicates possible contributions from exercise-induced hypoxemia or reoxygenation. Utilizing an environmental hypoxic chamber, this crossover designed study aimed to evaluate urinary alpha-1 acid glycoprotein (α1-AGP) excretion pre/post exercise performed in hypoxia and normoxia. Methods: Sixteen individuals underwent experimental sessions in normoxia (NOR, 20.9% O2) and hypoxia (HYP, 12.0% O2). Sessions began with a 2-hour priming period before completing a graded maximal exercise test (GXT) on a cycle ergometer, which was followed by continuation of exposure for an additional 2 hours. Physiologic responses (i.e., blood pressure, heart rate, and peripheral oxygenation), Lake Louise Scores, and urine specimens (analyzed for albumin and α1-AGP) were collected pre- and post-exercise (after 30, 60, and 120 minutes). Results: Peak power output was significantly reduced in HYP (193 ± 45 W) compared to NOR (249 ± 59 W, p < 0.01). Post-exercise urinary α1-AGP was greater in NOR (20.04 ± 14.84 μg•min-1) compared to HYP (15.08 ± 13.46 μg•min-1), albeit the difference was not significant (p > 0.05). Changes in urinary α1-AGP from pre- to post-30 minutes were not related to physiologic responses or performance outcomes observed during GXT in NOR or HYP. Conclusion: Despite profound systemic hypoxemia with maximal exercise in hypoxia, post-exercise α1-AGP excretion was not elevated above levels observed following normoxic exercise.


1989 ◽  
Vol 66 (6) ◽  
pp. 2491-2495 ◽  
Author(s):  
S. K. Powers ◽  
J. Lawler ◽  
J. A. Dempsey ◽  
S. Dodd ◽  
G. Landry

Recent evidence suggests that heavy exercise may lower the percentage of O2 bound to hemoglobin (%SaO2) by greater than or equal to 5% below resting values in some highly trained endurance athletes. We tested the hypothesis that pulmonary gas exchange limitations may restrict VO2max in highly trained athletes who exhibit exercise-induced hypoxemia. Twenty healthy male volunteers were divided into two groups according to their physical fitness status and the demonstration of exercise-induced reductions in %SaO2 less than or equal to 92%: 1) trained (T), mean VO2max = 56.5 ml.kg-1.min-1 (n = 13) and 2) highly trained (HT) with maximal exercise %SaO2 less than or equal to 92%, mean VO2max = 70.1 ml.kg-1.min-1 (n = 7). Subjects performed two incremental cycle ergometer exercise tests to determine VO2max at sea level under normoxic (21% O2) and mild hyperoxic conditions (26% O2). Mean %SaO2 during maximal exercise was significantly higher (P less than 0.05) during hyperoxia compared with normoxia in both the T group (94.1 vs. 96.1%) and the HT group (90.6 vs. 95.9%). Mean VO2max was significantly elevated (P less than 0.05) during hyperoxia compared with normoxia in the HT group (74.7 vs. 70.1 ml.kg-1.min-1). In contrast, in the T group, no mean difference (P less than 0.05) existed between treatments in VO2max (56.5 vs. 57.1 ml.kg-1.min-1). These data suggest that pulmonary gas exchange may contribute significantly to the limitation of VO2max in highly trained athletes who exhibit exercise-induced reductions in %SaO2 at sea level.(ABSTRACT TRUNCATED AT 250 WORDS)


Author(s):  
Dr. K. Rama Subba Reddy ◽  
Dr. T V Bala Krishna Reddy

The purpose of this study is to explore various changes occur in different physical and physiological systems of the body with respect to the relevant chronic exercises. Acute and Chronic exercise programmes develops physiological adaptations in different systems of the body, due to the stress places on the systems. Acute exercise refers to short duration exercise, such as a cycle ergometer or a treadmill maximal exercise test. Chronic refers to extended or long term exercise, such a physical training programme of four to six months duration.


1996 ◽  
Vol 21 (4) ◽  
pp. 264-270 ◽  
Author(s):  
Michael J. Buono ◽  
Richard Maly

The purpose of this study was to determine if augmented hyperventilation produced via normoxic helium breathing would reduce exercise-induced hypoxemia (EIH). Seven highly trained endurance athletes with a mean maximum oxygen uptake of 65 ml∙kg−1∙min−1, performed two cycle ergometer tests to volitional exhaustion. During one of the tests the subjects breathed ambient air, while during the other they breathed normoxic helium (21% O2, 79% He). Mean maximum expired ventilation significantly (p <.05) increased from 139 L∙min−1 during the ambient trial to 168 L∙min−1 while breathing normoxic helium. Mean arterial oxygen saturation obtained at maximum exercise, however, was not significantly different for the two trials (ambient = 90%, helium = 89%). These results suggest that significantly augmenting exercise hyperventilation by 21% essentially had no effect on EIH in endurance athletes. Thus, the data do not support the hypothesis that inadequate hyperventilation is an important mechanism for arterial oxygen desaturation during graded exercise to exhaustion in highly trained individuals. Key words: arterial oxygen saturation, endurance athletes, maximal exercise


Author(s):  
Shehnaz Shaikh

Introduction: Menstrual cycle or menstruation involved discharge of sanguinous fluid and a sloughing of uterine wall. In women menstruation occurs at regular intervals on an average of 28 days, although most women gave a history of regular intervals of 28 to 30 days. About 10% -15% of women showed cycle at the precise 28 ± 2 days intervals when menstrual calendar was utilized. Normally in young women in different phases of ovarian cycles the plasma levels of estrogen vary. Ovulation occurs in the first 12-13th day of menstrual cycle, which is termed estrogen surge and second occurs in mid-luteal phase. During mid cycle or follicular phase of menstrual cycle the plasma concentration of progesterone is very low about 0.9 ng/mL. its level starts rising owing to secretion from the granulose cells. During luteal phase progesterone level reaches its peak value of 18 ng/mL and its level fall to a minimum value toward the end of the cycle. Estrogen affects local and systemic vasodilation. The menstrual cycle envelops two fundamental stages, the follicular stage (FP) and the luteal stage (LP). The follicular stage can part advance into two substages; the early FP, which is characterised with moo concentrations of both the key hormones estrogen and progesterone; and the mid FP where estrogen is tall autonomously from progesterone. The LP is epitomized by tall concentration of both estrogen and progesterone. These two fundamental stages are isolated by a soak surge in luteinizing hormone activating ovulation. These recurrent changes are said to be frequency unsurprising while long time. Aim: The main aim of this study is to evaluate the Cardiorespiratory functions changes during different Phases of Menstrual Cycle.   Material and methods: In this study, 20 with normal weight, 20 with obese and 20 with overage were included and taken them as a sample size. In this study all the young women those were recruited as a sample size are unmarried, undergraduate female student with the between the age group of 18-22years, having regular 28+6 days menstrual cycle for at least last 6months prior to this study. For the collection of data all the participants were instructed to attend the physiology lab department during each of three different phases. Day-2 during menstrual phase, Day-7, during follicular phase and Day-22 during luteal phase and the following parameters were recorded as Anthropometric measurements, measuring of pulse rate and blood pressure and cardiac efficiency test. Result: In general, work out proficiency changed essentially amid the distinctive stages of the menstrual cycle with the most elevated amid luteal stage and least amid menstrualo stage. There was no critical contrast in impact test amid menstrual stage, follicular stage and luteal stage of menstrual cycle among three bunches of people. Conclusion: We have watched noteworthy increment in cardiac and respiratory proficiency within the luteal stage of the menstrual cycle in ordinary weight people. Lower wellness levels were watched in overweight and stout females. In this manner hone of customary work out and admissions of solid slim down which offer assistance in lessening the weight and in turn the BMI will offer assistance in improving the physical wellness of the people. Keywords: Cardiorespiratory, Menstrual cycle, expiratory blast test


1979 ◽  
Vol 90 (2) ◽  
pp. 372-384 ◽  
Author(s):  
N. P. Goncharov ◽  
A. G. Taranov ◽  
A. V. Antonichev ◽  
V. M. Gorlushkin ◽  
T. Aso ◽  
...  

ABSTRACT Adult baboons (5 males and 5 females) were exposed to immobilization stress by being strapped to a table in a horizontal position for 2 h. In females the experiment was performed during both the follicular and luteal phase. Peripheral blood was withdrawn at frequent intervals, the first sample just before immobilization, and the last one 3 days later. A number of steroids were measured in blood plasma samples by radioimmunoassay (17-hydroxypregnenolone, 17-hydroxyprogesterone, pregnenolone, testosterone, dihydrotestosterone, progesterone, 20α-dihydroprogesterone, oestrone, oestradiol) or competitive protein binding (cortisol) techniques. The cortisol levels exhibited a marked increase in both sexes. This increase was observed already during the immobilization and lasted for approximately 24 h. A similar, even more pronounced increase was seen in 17-hydroxypregnenolone, 17-hydroxyprogesterone and pregnenolone levels. A marked, long-lasting (72 h) decrease of testosterone and dihydrotestosterone levels was a consistent finding in male baboons. This was not observed in the females which, on the other hand, exhibited a marked decrease (duration 48 h) of progesterone and 20α-dihydroprogesterone levels during the luteal phase, and a significant decrease (duration > 24 h) of oestradiol and oestrone concentrations during the follicular phase. It is concluded that stress has a marked inhibitory action on gonadal function both in male and female baboons. In females the inhibition of steroidogenetic function is exerted both on the ovarian follicles and on the corpus luteum.


1990 ◽  
Vol 68 (5) ◽  
pp. 2177-2181 ◽  
Author(s):  
M. Manohar

Regional distribution of diaphragmatic blood flow (Q; 15-microns-diam radionuclide-labeled microspheres) was studied in normal (n = 7) and laryngeal hemiplegic (LH; n = 7) ponies to determine whether the added stress of inspiratory resistive breathing during maximal exercise may cause 1) redistribution of diaphragmatic Q and 2) crural diaphragmatic Q to exceed that in maximally exercising normal ponies. LH-induced augmentation of already high exertional work of breathing resulted in diminished locomotor exercise capacity so that maximal exercise in LH ponies occurred at 25 km/h compared with 32 km/h for normal ponies. The costal and crural regions received similar Q in both groups at rest. However, exercise-induced increments in perfusion were significantly greater in the costal region of the diaphragm. At 25 km/h, costal diaphragmatic perfusion was 154 and 143% of the crural diaphragmatic Q in normal and LH ponies. At 32 km/h, Q in costal diaphragm of normal ponies was 136% of that in the crural region. Costal and crural diaphragmatic Q in LH ponies exercised at 25 km/h exceeded that for normal ponies but was similar to the latter during exercise at 32 km/h. Perfusion pressure for the three conditions was also similar. It is concluded that diaphragmatic perfusion heterogeneity in exercising ponies was preserved during the added stress of inspiratory resistive breathing. It was also demonstrated that vascular resistance in the crural and costal regions of the diaphragm in maximally exercised LH ponies remained similar to that in maximally exercising normal ponies.


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