The role of DHEA-S in the mood adjustment against negative competition outcome in golfers.

Several lines of evidence suggest that dehydroepiandrosterone sulphate (DHEA-S) is invariably consumed following different types of acute stress, implicating its role in stress coping and recovery. The role of DHEA-S in the mood adjustment against negative outcome for athletic competition has not previously been investigated. In the current study, 14 elite golfers participating in a major national golf tournament were subsequently divided into two groups according to their competition outcomes: made the cut (n=8) and failed to make the cut (n 8).

Iron status and cardiovascular risk factors in patients with haemodialysis versus patients with ischaemic heart disease.

Aim: The study aimed to investigate whether imbalanced iron status in patients with haemodialysis coexisted with abnormal lipid profile, higher inflammatory status and altered growth hormone-insulin-like growth factor (GH-IGF)-I axis and to compare these biochemical markers with patients with ischaemic heart disease.

Methods: Serum samples for biochemical and immunological analyses were collected from 74 normal subjects, 138 patients with ischaemic heart disease (IHD) and 115 patients on haemodialysis (HD).

Results: Compared with normal subjects, lower serum iron, lower total iron-binding capacity (TIBC) and higher ferritin in HD patients coexisted with decreases in high-density lipoprotein cholesterol and total bilirubin as well as increases in lactate dehydrogenase (LDH), interleukin (IL)-6, C-reactive protein (CRP) and IL-10.

Cardiac Fas-dependent and mitochondria-dependent apoptosis in ovariectomized rats.

Background: Very limited information has been published regarding cardiac apoptosis in menopausal women or in those after bilateral oophorectomy. The purpose of this study was to evaluate whether cardiac Fas-dependent (type I) and mitochondria-dependent (type II) apoptotic pathways are activated in ovariectomized rats.

Methods: Thirty-two female Wistar rats at 6-7 months of age were randomly divided into sham-operated group (Sham) and bilateral ovariectomized group (OVX).

Effects of short-term detraining on measures of obesity and glucose tolerance in elite athletes.

Athletes frequently adjust their training volume in line with their athletic competition schedule, onset of sport injury, and retirement. Whether maintenance of partial training activity during the detraining period can preserve optimal body composition and insulin sensitivity is currently unknown. Sixteen elite kayak athletes (mean VO2max: 58.

Effects of swimming on the pharmacokinetics and glucose tolerance of metformin in insulin-resistant rats.

The purpose of the study was to investigate the effects of swimming on the pharmacokinetic and insulin sensitivity of metformin in insulin resistant rats. Rats with fructose-induced insulin resistance were assigned into four groups: control group (C, n=8), metformin group (M, n=8), swimming group (S, n=8) and metformin with swimming group (MS, n=8). After 12 h of fasting, the S and MS group swam for 45 min, while the M and C groups were placed in 4 cm deep water for the same time period.

IGF-II/mannose-6-phosphate receptor signaling induced cell hypertrophy and atrial natriuretic peptide/BNP expression via Galphaq interaction and protein kinase C-alpha/CaMKII activation in H9c2 cardiomyoblast cells.

The role played by IGF-II in signal transduction through the IGF-II/mannose-6-phosphate receptor (IGF2R) in heart tissue has been poorly understood. In our previous studies, we detected an increased expression of IGF-II and IGF2R in cardiomyocytes that had undergone pathological hypertrophy. We hypothesized that after binding with IGF-II, IGF2R may trigger intracellular signaling cascades involved in the progression of pathologically cardiac hypertrophy.

The coexistence of nocturnal sustained hypoxia and obesity additively increases cardiac apoptosis.

Background: nocturnal sustained hypoxia during sleeping time has been reported in severe obesity, but no information regarding the cardiac molecular mechanism in the coexistence of nocturnal sustained hypoxia and obesity is available. This study evaluates whether the coexistence of nocturnal sustained hypoxia and obesity will increase cardiac Fas death receptor and mitochondrial-dependent apoptotic pathway.

Methods: 32 lean and 32 obese 5- to 6-mo-old rats with or without nocturnal sustained hypoxia were studied and assigned to one of four subgroups: normoxia lean (NL), normoxia obese (NO), hypoxia lean (HL, 12% O(2) for 8 h and 21% O(2) 16 h/day, 1 wk), and hypoxia obese (HO).

Glycogen content and contraction regulate glycogen synthase phosphorylation and affinity for UDP-glucose in rat skeletal muscles.

Glycogen content and contraction strongly regulate glycogen synthase (GS) activity, and the aim of the present study was to explore their effects and interaction on GS phosphorylation and kinetic properties. Glycogen content in rat epitrochlearis muscles was manipulated in vivo. After manipulation, incubated muscles with normal glycogen [NG; 210.

Effect of a two-month detraining on glucose tolerance and insulin sensitivity in athletes--link to adrenal steroid hormones.

Reduction in physical activity has been demonstrated to associate with the increased risk in insulin resistance and type 2 diabetes. To determine whether alteration in insulinemia, due to abstention from regular exercise training, is associated with changes in serum dehydroepiandrosterone sulfate (DHEA-S) and cortisol, 18 highly trained badminton players (21.2 +/- 0.

Validity of the 3 min step test in moderate altitude: environmental temperature as a confounder.

The 3 min step test is a widely used method to evaluate physical fitness, but whether this method is valid when performed at altitude is unknown. The purpose of this study was to examine the effect of altitude on the fitness score of the 3 min step test, and the role of ambient temperature in this effect. In study I, 11 healthy volunteers (aged 18.

A possible link between exercise-training adaptation and dehydroepiandrosterone sulfate- an oldest-old female study.

The purpose of this study was to determine the association between the level of salivary dehydroepiandrosterone sulfate (DHEA-S) and the magnitude of adaptation to exercise training in insulin sensitivity for aged females. A group of 16 females, aged 80-93 years old, was divided into 2 groups according to their baseline DHEA-S levels: Lower Halves (N = 8) and Upper Halves (N = 8), and participated in a 4-month exercise intervention trial. Insulin response with an oral glucose tolerance test (OGTT), cholesterol, blood pressure (BP), motor performance, and DHEA-S were determined at baseline and 4 months after the training program.

The role of dehydroepiandrosterone levels on physiologic acclimatization to chronic mountaineering activity.

Previous studies have reported that glucose tolerance can be improved by short-term altitude living and activity. However, not all literature agrees that insulin sensitivity is increased at altitude. The present study investigated the effect of a 25-day mountaineering activity on glucose tolerance and its relation to serum levels of dehydroepiandrosterone-sulfate (DHEA-S) and tumor necrosis factor-alpha (TNF-alpha) in 12 male subjects.

Glucose tolerance and insulin sensitivity following an one-week volleyball competition.

The purpose of the study was to compare glucose tolerance and insulin sensitivity between trained (TR) and competition (CP) states, in relation to cortisol and testosterone levels. Sixteen highly trained volleyball players voluntarily participated in this study. The first testing session (TR state) occurred 1 week before the start of national level volleyball CP, and the second testing session (CP state) occurred next morning after the 1-week CP.

Effect of resistance exercise on dehydroepiandrosterone sulfate concentrations during a 72-h recovery: relation to glucose tolerance and insulin response.

Serum dehydroepiandrosterone sulfate (DHEA-S) concentration is known to be associated with the whole-body insulin sensitivity. The main purpose of the study was to investigate the effect of resistance exercise on DHEA-S concentration during a 72 h post-exercise recovery, and its relation to glucose tolerance and insulin sensitivity. Morning fasted serum samples was obtained from 19 male volunteers (aged 21.

Exercise training exacerbates tourniquet ischemia-induced decreases in GLUT4 expression and muscle atrophy in rats.

The current study determined the interactive effects of ischemia and exercise training on glycogen storage and GLUT4 expression in skeletal muscle. For the first experiment, an acute 1-h tourniquet ischemia was applied to one hindlimb of both the 1-week exercise-trained and untrained rats. The contralateral hindlimb served as control.

Glycogen overload by postexercise insulin administration abolished the exercise-induced increase in GLUT4 protein.

To elucidate the role of muscle glycogen storage on regulation of GLUT4 protein expression and whole-body glucose tolerance, muscle glycogen level was manipulated by exercise and insulin administration. Sixty Sprague-Dawley rats were evenly separated into three groups: control (CON), immediately after exercise (EX0), and 16 h after exercise (EX16). Rats from each group were further divided into two groups: saline- and insulin-injected.

Acute effect of exercise-hypoxia challenge on GLUT4 protein expression in rat cardiac muscle.

Altitude training is a frequently used method for enhancing endurance performance in athletes. But its acute effect on carbohydrate metabolism in cardiac muscle is unknown. In this study, we determined the acute effect of an exercise-hypoxia challenge on glycogen storage and GLUT4 protein expression in heart muscle.

Motor control in patients with incomplete spinal cord injuries and various voluntary movement capabilities.

Background: In this study, we attempted to verify the hypothesis that further improvements in volitional movement of patients with a spinal cord injury would diminish and ultimately suppress the segmental responses, while enhancing the supraspinal inhibitory influence.

Methods: Eleven patients with an incomplete spinal cord injury and partial preservation of motor function (ASIS grades C and D) were recruited. Their lower limbs were evaluated using polyelectromyography (PEMG) during voluntary movements, reinforcement maneuvers, tonic vibratory reflex, passive stretch reflex, irradiation of the passive stretch reflex (PSRirrad), and plantar reflex suppression.

Interactive effect of an acute bout of resistance exercise and dehydroepiandrosterone administration on glucose tolerance and serum lipids in middle-aged women.

The present study determined the interactive effect of an acute bout of resistance exercise and dehydroepiandrosterone (DHEA) administration on glucose tolerance and serum lipids. Twenty middle-aged female subjects performed an acute bout of resistance exercise and were subsequently divided into two groups: placebo (age 40.7 +/- 2.

Effect of postexercise carbohydrate supplementation on glucose uptake-associated gene expression in the human skeletal muscle.

We previously found that the exercise-induced elevation in GLUT4 mRNA of rat muscle can be rapidly down-regulated when glucose is given immediately following exercise. The purpose of this study was to determine the effect of postexercise carbohydrate diet on GLUT4 and hexokinase (HK) II mRNA levels in the human skeletal muscle. Eight untrained male subjects (age, 20.

Characteristics of glycemic control in elite power and endurance athletes.

A previous study has shown that former elite power athletes exhibited significantly greater relative risk in diabetes than that of former elite endurance athletes. It is unknown whether insulin sensitivity in elite young healthy power athletes is lower than that in elite young endurance athletes. This study includes two parts, part I and part II.

Effect of systemic hypoxia on GLUT4 protein expression in exercised rat heart.

Altitude training is a common method used to enhance endurance performance in athletes. We have examined the interactive effect of exercise training and chronic hypoxic on glycogen storage and GLUT4 protein expression in cardiac muscles. Thirty-two male Sprague-Dawley rats were weight balanced and assigned to one of the following four groups: control, exercise, hypoxia, and hypoxia-exercise.

Effect of prolonged intermittent hypoxia and exercise training on glucose tolerance and muscle GLUT4 protein expression in rats.

We compared the chronic effect of intermittent hypoxia and endurance training on the glucose tolerance and GLUT4 protein expression in rat skeletal muscle. Thirty-two Sprague-Dawley rats were matched for weight and assigned to one of the following four groups: control, endurance training, hypoxia, or hypoxia followed by endurance training. Hypoxic treatment consisted of breathing 14% O2 for 12 h/day under normobaric conditions, and the training protocol consisted of making animals swim 2 times for 3 h/day.

Effects of hiking at altitude on body composition and insulin sensitivity in recovering drug addicts.

In the current study individuals with a history of drug abuse (users of heroin, cocaine, or amphetamine) displayed a 13-100% increase in body weight (self-reported) and exhibited a trend toward insulin resistance. Therefore, we investigated the effects of long-term altitude hiking on insulin sensitivity in this special population. Nine males recovering from drug addiction (ex-addicts) (age 28.

Interactive effect of exercise training and growth hormone administration on glucose tolerance and muscle GLUT4 protein expression in rats.

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 exercise training + GH groups.