Search Results
Results 451 - 500 of 1067
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Kraemer R R - - 2004
OBJECTIVE: Heavy resistance exercise increases growth hormone (GH) and blood glucose levels. Ghrelin is an endogenous ligand for the GH secretagory receptor that stimulates growth hormone release. Circulating ghrelin levels are suppressed by insulin and glucose. The study was conducted to determine effects of concentric (CON) and eccentric (ECC) muscle ...
Ari Zeki - - 2004
The aim of the study was to investigate the effect of regular exercise on maximum oxygen uptake capacity (VO2max), reaction time (RT), testosterone (T), growth hormone (GH), insulin-like growth factor-I (IGF-I) in athletes compared to sedentary controls. VO2max, RT, T, GH, and IGF-I levels were 31.2 +/- 6.2 ml/min/kg, 106.7 ...
Nemet Dan - - 2004
PURPOSE: Brief periods of aerobic exercise training lead to reductions, rather then the expected increases in circulating IGF-I. We hypothesized that intense exercise training in adolescents initially leads to simultaneous increases in proinflammatory cytokines and decreases in activity of the GH/IGF-I axis; and that as exercise training proceeds, levels of ...
Boag A K - - 2004
A 14-year-old neutered female cat was presented for the investigation of aggression and male-type behaviour. Bilateral adrenal enlargement together with elevated plasma concentrations of oestradiol and testosterone were identified, with no evidence of hypercortisolaemia. These findings are similar to the syndrome of hyperadrenocorticism recognised most commonly in ferrets. The cat ...
Jiang Jinlong - - 2004
Syntheses and structure-activity relationships of piperidine-substituted quinolones as nonpeptide gonadotropin releasing hormone antagonists are described. Some of substituents on the piperidine ring that were investigated included a fused phenyl group, a (6R)-trifluoromethyl group, (6S) and (6R)-methyl group. This study showed that GnRH binding potency was tolerated by a small group ...
Di Loreto C - - 2004
Whole-body vibration is reported to increase muscle performance, bone mineral density and stimulate the secretion of lipolytic and protein anabolic hormones, such as GH and testosterone, that might be used for the treatment of obesity. To date, as no controlled trial has examined the effects of vibration exercise on the ...
Kirwan Lori D - - 2004
Previous studies have shown that conjugated estrogens and continuous medroxyprogesterone increases heart disease risk in healthy women. Little is known about the effects of the natural ovarian hormones estradiol and progesterone on cardiovascular function at rest and exercise. The purpose of this study was to investigate the short- and longer-term ...
Piacentini M F - - 2004
OBJECTIVE: A decrease in dopamine activity is thought to lead to a reduction in motivation and arousal and therefore to the "central" component of fatigue. The purpose of the present study was to investigate the effects of a dopamine (DA) noradrenaline (NA) reuptake inhibitor, bupropion (Zyban), on exercise performance and ...
Kraemer R R - - 2004
It has been suggested that ghrelin may play a role in growth hormone (GH) responses to exercise. The present study was designed to determine whether ghrelin, GH, insulin-like growth factor-I (IGF-I), and IGF-binding protein-3 (IGFBP-3) were altered by a progressively intense running protocol. Six well-trained male volunteers completed a progressively ...
Schmidt A - - 2004
Exercise is a potent, dose-dependent stimulus of growth hormone (GH) secretion. The hypothalamic peptides, GH-releasing hormone (GHRH) and somatostatin are regarded as major regulators of this stimulation. The role of the stomach-derived peptide ghrelin, which has been shown to exert strong GH releasing effects, has not been fully characterized yet. ...
Dalsgaard Mads K - - 2004
Strenuous exercise increases the cerebral uptake of carbohydrate out of proportion to that of oxygen, but it is unknown whether such enhanced carbohydrate uptake is influenced by the marked endocrine response to exercise. During exhaustive exercise this study evaluated the a-v differences across the brain (a-v diff) of hormones that ...
Rønsen Ola - - 2004
The purpose of this study was to characterize the extent of immune, endocrine, substrate and metabolic changes during a long-distance cross-country ski race in extremely well-trained athletes and evaluate if the blood perturbations would indicate signs of health risk. Ten male (M) and six female (F) national team skiers were ...
Veldhuis Johannes D - - 2004
GH represses its own secretion via rapid and reversible feedback exerted at key hypothalamic loci. The primary mechanisms include stimulation of somatostatin release and inhibition of GHRH outflow. Autoinhibition is prominent in the adult male rat but diminutive in the female animal. The sex contrast reflects important differences in central ...
Weise Martina - - 2004
Classic congenital hyperplasia (CAH) is characterized by impaired adrenocortical function with a decrease in cortisol and aldosterone secretion and an increase in androgen secretion. Adrenomedullary function is also compromised due to developmental defects in the formation of the adrenal medulla, leading to decreased production of epinephrine. To examine the response ...
Copeland Jennifer L - - 2004
Aging is associated with a decline in bone mass, muscle mass, strength, and physical function, and women are more likely to suffer from these physical changes than men. The model presented in this paper illustrates the age related changes in anabolic hormones and how this may partly explain the diminished ...
Huang Wen-Sheng - - 2004
OBJECTIVES: Effects of exercise on circulating thyroid hormone (TH) values remain controversial. We sought to observe the effect of treadmill exercise on serum TH values in highly selected subjects. METHODS: Twenty-six healthy male military recruits aged 23-27 (mean, 25) years were studied. All had maintained identical diet and physical activity ...
Copeland Jennifer L - - 2004
Women experience significant changes in endocrine function during aging. Decreasing levels of anabolic hormones may be associated with musculoskeletal atrophy and decrease in function that is observed in older women and, as a result, there has been an increase in the use of pharmacological hormone therapies. It is difficult to ...
Bird Stephen P - - 2004
Both testosterone (T) and cortisol (C) exhibit circadian rhythmicity being highest in the morning and lowest in the evening. T is a potent stimulator of protein synthesis and may possess anti-catabolic properties within skeletal muscle, and C affects protein turnover, thereby altering the balance between hormone-mediated anabolic and catabolic activity. ...
Berg Ulrika - - 2004
Determinations of serum concentrations of total insulin-like growth factor I (tIGF-I) are important in the diagnosis, monitoring of treatment and safety evaluation of patients with growth disorders and/or metabolic disease. It is well established that tIGF-I status varies over time. Changes in tIGF-I levels in relation to an acute bout ...
Hütler Matthias - - 2004
Cystic fibrosis (CF) is a life-limiting inherited disorder characterised by pulmonary disease, pancreatic dysfunction and symptoms of malnutrition that are all interrelated with low exercise capacity and poor survival rate. Therapy with growth hormone (GH) may improve the reduced dimensional and functional capacity associated with poor nutritional status and catabolism ...
Risøy Bjørn Audun - - 2003
During infections, polymorphonuclear neutrophilic granulocytes (PMN) are mobilized from their bone marrow stores, travel with blood to the affected tissue, and kill invading microbes there. The signal(s) from the inflammatory site to the marrow are unknown, even though a number of humoral factors that can mobilize PMN, are well known. ...
Giannopoulou I - - 2003
The purpose of this study was to determine whether racial differences exist in the dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DHEAS), and cortisol concentrations of black and white postmenopausal women at rest and in response to submaximal exercise. Twenty-three postmenopausal women (13 white and 10 black) were studied on 2 occasions. On ...
Ay Alev - - 2003
OBJECTIVE: This study is based on whether moderate increased physical activity as aquatic exercise has anabolic effects on bone and evaluates this in terms of quantitative ultrasound and hormonal variables. DESIGN: In this study, 41 postmenopausal sedentary women were admitted to Atatürk Balneotherapy and Rehabilitation Center, according to T scores ...
Thomas Scott G - - 2003
Reduced aerobic capacity is a prominent manifestation among patients with GH deficiency (GHD). Exercise training may improve the physiological capacity to undertake aerobic activity. The ability of patients with GHD to participate in and benefit from a structured program of aerobic exercise with or without replacement recombinant human GH (rhGH) ...
Hebbeler Sara L - - 2003
The lumbar spinal cord of rats contains the sexually dimorphic, steroid-sensitive spinal nucleus of the bulbocavernosus (SNB). In male rats, SNB motoneurons exhibit a biphasic pattern of dendritic growth, having an initial period of exuberant growth followed by a period of retraction to mature lengths by 7 weeks of age. ...
Gutiérrez A - - 2003
AIM: Physical exercise in recreational mountain sports is frequently performed without acclimatization to hypoxic conditions. Hypoxia may modify the hormonal and metabolic adaptive response to exercise depending on the type of exercise and on the physical fitness of the subject. This study aims at investigating the growth hormone (GH) response ...
Steinacker Jürgen M - - 2004
Exercise training is associated with peripheral-cellular and central-cerebral processes, hormonal-neuronal regulation and transmission mechanisms. During the acute training response, peripheral cellular mechanisms are mainly metabolostatic to achieve energy supply and involve associated cytokine and hormonal reactions. Glycogen deficiency is associated with increased expression of local cytokines (interleukin-6, IL-6), decreased expression ...
Di Luigi L - - 2003
To evaluate the role of heredity in the pituitary responses to exercise-related stress, serum ACTH, beta-endorphin, cortisol, GH, and PRL responses to a thirty-minute treadmill exercise at individual anaerobic threshold were evaluated in nine pairs of male monozygotic twin athletes. Hormone evaluations were performed before (-30, -15, 0 pre) and ...
Hoffman Jay R - - 2003
PURPOSE: The mechanisms that underlie the affect of acute program variables on muscle growth and strength development for strength/power athletes have been of great interest. This investigation examined the affects of two different resistance exercise protocols on muscle oxygenation, and the anabolic hormonal response to such exercise. METHODS: Eleven experienced ...
Turgut Günfer - - 2003
Insulin-like growth factor-I (IGF-I) is a polypeptide hormone and present in human urine. Insulin-like growth factor binding protein-3 (IGFBP-3) is the major form of binding protein in human circulation and functions as a carrier for IGF-I. Our goal was to determine the effects of volleyball exercise on the concentrations of ...
Healy M L - - 2003
The anabolic actions of GH in GH-deficient adults and children are well documented. Replacement with GH in such individuals promotes protein synthesis and reduces irreversible loss of protein through oxidation. Although GH is known to be self-administered by athletes, its protein metabolic effects in this context are unknown. This study ...
Hou Chien-Wen - - 2003
The insulin-resistance effect of growth hormone (GH) administration has been frequently reported. The present study investigated the effect of GH administration on glucose tolerance and muscle GLUT4 protein expression in exercise-trained and untrained rats. Forty-eight rats were weight-matched and assigned to the following 4 groups: control, GH, exercise training, and ...
Yehuda Rachel - - 2003
The assessment of lysozyme activity in mononuclear leukocytes (MNLs) following the in vitro administration of dexamethasone (DEX) provides a measure of peripheral glucocorticoid sensitivity. The goal of the present study was to determine the relationship between the IC(50) of lysozyme activity following such challenge, and the cortisol response to oral ...
Kanaley Jill A - - 2004
The secretion of growth hormone (GH) increases acutely during exercise, but whether this is associated with the concomitant alterations in substrate metabolism has not previously been studied. We examined the effects of acute GH administration on palmitate, glucose, and protein metabolism before, during, and after 45 min of moderate-intensity aerobic ...
Keenan Daniel M - - 2004
The present study extends a recent composite model of in vivo interglandular signaling to assess the impact of age on 1) nonequilibrium exchange among diffusible and protein-bound testosterone (Te); 2) elimination of total and free Te; 3) basal and pulsatile Te secretion (sec); 4) the implicit feedforward function mediating luteinizing ...
Stokes Keith - - 2003
Exercise is a potent stimulus for growth hormone (GH) release and a single bout of exercise can result in marked elevations in circulating GH concentrations. The magnitude of the GH response to exercise will vary according to the type, intensity and duration of exercise as well as factors such as ...
Nindl Bradley C - - 2003
There are more than 100 molecular isoforms of circulating growth hormone (GH), but the traditional measurement approach in the exercise literature has only focused on the main isoform (i.e., 22 kDa). New assay methodologies now can assess various GH isoforms. The current data suggest that exercise results in the preferential ...
Bongiorni Lucia - - 2003
This field study aims to determine whether increased levels of organically enriched particulate matter released by net pen fish farms (Eilat, Red Sea) would affect the growth of nubbins taken from the branching coral Stylophora pistillata. We followed the survival and growth of 1322 nubbins pruned from five colonies that ...
Weltman A - - 2003
GH secretion declines with aging and is decreased in conditions such as obesity. Several physiologic factors alter pulsatile GH secretion, including age, gender, body composition, regional distribution of fat and in particular abdominal visceral fat, sleep, nutrition, exercise and serum concentrations of gonadal steroids, insulin and IGF-I. Acute aerobic exercise ...
Kraemer W J - - 2003
The purpose of this investigation was to determine the influence of physical strength and the ability to do more total work on human growth hormone (GH) variants to a heavy resistance exercise protocol in untrained women. From a distribution of 100 healthy, untrained women, the strongest 10 women (S) and ...
Jørgensen J O L - - 2003
That physical exercise stimulates pituitary GH secretion has been known for forty years, but the underlying mechanisms as well as the physiological significance remain elusive. We have previously shown that the concomitant increase in core temperature is essential for the exercise-induced GH release, inasmuch as exercise performed at 4 C ...
Leal-Cerro A - - 2003
Exercise initiates a coordinated series of physiological responses, including hypothalamic-pituitary-adrenal (HPA) axis and sympathetic nervous system activation, that, in combination, lead to the appropriate selection and utilization of metabolic substrates. Physical activity acts as a powerful stimulus for the hypothalamic-pituitary axis, leading to the liberation of several neuroendocrine hormones. The ...
Nemet Dan - - 2004
Circulating IGF-I is correlated with fitness, but results of prospective exercise training studies have been inconsistent, showing both increases and decreases in IGF-I. We hypothesized that energy balance, often not accounted for, is a regulating variable such that training plus an energy intake deficit would cause a reduction in IGF-I, ...
Ahtiainen J P - - 2003
Acute hormonal and neuromuscular responses and recovery three days after the exercises were examined during the maximum repetitions (MR) and forced repetitions (FR) resistance exercise protocols in 16 male athletes. MR included 4 sets of leg presses, 2 sets of squats and 2 sets of knee extensions (with 12 RM) ...
Fairey Adrian S - - 2003
Insulin, insulin-like growth factors (IGFs) I and II, and IGF binding proteins (IGFBPs) 1 and 3 have been implicated in breast cancer outcomes. We conducted a randomized controlled trial to determine the physiological effects of exercise training on changes in these biological markers in postmenopausal breast cancer survivors. Fifty-three postmenopausal ...
Kraemer William J - - 2003
The purpose of this investigation was to examine the influence of L-carnitine L-tartrate (LCLT) supplementation using a balanced, cross-over, placebo-controlled research design on the anabolic hormone response (i.e., testosterone [T], insulin-like growth factor-I, insulin-like growth factor-binding protein-3 [IGFBP-3], and immunofunctional and immunoreactive growth hormone [GHif and GHir]) to acute resistance ...
Lafortuna C L - - 2003
Acute plasma GH response to prolonged (1 h) near-maximal exercise was studied in 7 elite cyclists (6 males, 1 female; mean age +/- SE: 24.9 +/- 1.4 yr) during a routine training session on an uphill track (length: 22.0 km, average slope: 4.39%) and during a recovery (REC) period of ...
Kemmler W - - 2003
The effect of a single bout of exercise on hormones affecting bone metabolism was studied in 25 early postmenopausal women with osteopenia. The complex training session was performed between 8:00 a.m. and 9:05 a.m. Serum concentrations of dehydroepiandrosterone-sulfate (DHEA-S), total testosterone, free testosterone, 17beta-estradiol, cortisol, human growth hormone (hGH), insulin-like ...
Purvis O W - - 2003
SO(2) is no longer the principal factor influencing the vitality and composition of lichen assemblages in London. We provide direct evidence for an impact on lichen growth during episodic high exhaust emissions coupled with unusual climatic conditions. This suggests a combination of particles and nitrogen plays a major role in ...
Duda K - - 2003
In the present experiment we have studied the effect of exercise performed before and 24 h after withdrawal of 450 ml of blood on the serum erythropoietin and growth hormone (GH) levels, in humans. Twelve male subjects (x +/- SD) aged 23.2 +/- 2.6 y, with a body mass of ...
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