Poor levels of agreement between serum and saliva testosterone measurement following exercise training in aging men.

Testosterone (T) is a biologically important androgen that demonstrates a widely-known natural decline with advancing age. The use of salivary T (sal-T), as a determinant of systemic T, has shown promising results in recent years. However, the strength of the salivary-serum T relationship may be affected by measurement method and binding capacity with salivary proteins.

Resting steroid hormone concentrations in lifetime exercisers and lifetime sedentary males.

Introduction: Advancing age in men is associated with a progressive decline in serum testosterone (T) and interactions between exercise, aging and androgen status are poorly understood. The primary aim of this study was to establish the influence of lifelong training history on serum T, cortisol (C) and sex hormone binding globulin (SHBG) in aging men. A secondary aim was to determine the agreement between serum and salivary measurement of steroid hormones in ageing men.

Exercise-induced oxidative-nitrosative stress is associated with impaired dynamic cerebral autoregulation and blood-brain barrier leakage.

The present study examined whether dynamic cerebral autoregulation and blood-brain barrier function would become compromised as a result of exercise-induced oxidative-nitrosative stress. Eight healthy men were examined at rest and after an incremental bout of semi-recumbent cycling exercise to exhaustion. Changes in a dynamic cerebral autoregulation index were determined during recovery from continuous recordings of blood flow velocity in the middle cerebral artery (MCAv) and mean arterial pressure during transiently induced hypotension.

Increased cerebral output of free radicals during hypoxia: implications for acute mountain sickness?

This study examined whether hypoxia causes free radical-mediated disruption of the blood-brain barrier (BBB) and impaired cerebral oxidative metabolism and whether this has any bearing on neurological symptoms ascribed to acute mountain sickness (AMS). Ten men provided internal jugular vein and radial artery blood samples during normoxia and 9-h passive exposure to hypoxia (12.9% O(2)).

Potential benefits of recombinant human growth hormone (rhGH) to athletes.

Athletes have enjoyed almost a thirty year amnesty of rhGH abuse, which they consider has contributed to the winning of medals and the breaking of world records. Such a reprieve is almost at an end, since WADA have identified a method to detect rhGH abuse. Or have they? The anecdotal word "on the street" is that rhGH is still undetectable and athletes believe that the benefits, at the dosages they administer, far outweigh the risks! Scientists are aware that in a hormone deficiency condition, replacement can halt and in certain situations reverse some of the adverse effects.

Physical effects of short-term recombinant human growth hormone administration in abstinent steroid dependency.

Background/aims: Recombinant human growth hormone (rhGH) as opposed to cadaver pituitary GH is misused for physical improvement. Six days' rhGH administration, in abstinent anabolic-androgenic steroid dependents, was compared with controls.

Method: Male subjects (n = 48) were randomly divided into two groups: (1): control group (C), n = 24, mean +/- SD, age 32 +/- 11 years, height 1.

Short-term recombinant human growth hormone administration improves respiratory function in abstinent anabolic-androgenic steroid users.

Objectives: To determine whether 6 days recombinant human growth hormone (rhGH) administration, in an abstinent anabolic-androgenic steroid (AAS) using group had any respiratory, endurance exercise and biochemical effects compared with an abstinent AAS control group.

Methods: Male subjects (n=48) were randomly divided, using a single blind procedure into two groups: (1) control group (C) n=24, means+/-SD, age 32+/-11 years; height 1.8+/-0.

Evidence for a decrease in cardiovascular risk factors following recombinant growth hormone administration in abstinent anabolic-androgenic steroid users.

Objectives: To determine whether six days recombinant human growth hormone (rhGH) in an abstinent anabolic-androgenic steroid (AAS) group had any cardiovascular and biochemical effects compared with a control group.

Methods: Male subjects (n=48) were randomly divided, using a single blind procedure into two groups: (1) control group (C) n=24, mean+/-SD, age 32+/-11 years; height 1.8+/-0.

Recombinant human growth hormone in abstinent androgenic-anabolic steroid use: psychological, endocrine and trophic factor effects.

This study examined whether six days recombinant human growth hormone (rhGH) affected psychological profile in an abstinent androgenic-anabolic steroid (AAS) abusing group, compared with an abstinent AAS control group. Male subjects (n = 48) were assigned in a random fashion into one of two groups: (1): (n=24) control group (C); (2): (n=24) rhGH group (GH). A hospital anxiety scale (HADS) questionnaire was completed by all subjects.

Vitamin C prophylaxis promotes oxidative lipid damage during surgical ischemia-reperfusion.

Reactive oxygen species (ROS) have been implicated in the cellular membrane damage and postoperative morbidity associated with obligatory ischemia-reperfusion (I-R) during vascular surgery. Thus, a clinical study was undertaken to evaluate the effects of ascorbate prophylaxis on ROS exchange kinetics in 22 patients scheduled for elective abdominal aortic aneurysm (AAA) or infra-inguinal bypass (IIB) repair. Patients were assigned double-blind to receive intravenous sodium ascorbate (2 g vitamin C, n=10) or placebo (0.

Manipulation of systemic oxygen flux by acute exercise and normobaric hypoxia: implications for reactive oxygen species generation.

Maximal exercise in normoxia results in oxidative stress due to an increase in free radical production. However, the effect of a single bout of moderate aerobic exercise performed in either relative or absolute normobaric hypoxia on free radical production and lipid peroxidation remains unknown. To examine this, we randomly matched {according to their normobaric normoxic VO2peak [peak VO2 (oxygen uptake)]} and assigned 30 male subjects to a normoxia (n = 10), a hypoxia relative (n = 10) or a hypoxia absolute (n = 10) group.

Metabolic implications of resistive force selection for oxidative stress and markers of muscle damage during 30 s of high-intensity exercise.

The purpose of this study was to compare power outputs, and blood concentrations of lipid hydroperoxides (LH), malondialdehyde (MDA), creatine kinase (CK), myoglobin (Mb) and lactate ([La-]B) following 30 s of maximal cycle ergometry when resistive forces were derived from total-body mass (TBM) or fat-free mass (FFM). Alpha-tocopherol (AT), retinol (R) and uric acid (UA) concentrations were also measured to qualify the activity of antioxidants. Cardiac troponin levels were determined to exclude myocardial damage and to verify that any CK was predominantly derived from skeletal muscle.

Symptoms of infection and acute mountain sickness; associated metabolic sequelae and problems in differential diagnosis.

Infections and acute mountain sickness (AMS) are common at high altitude, yet their precise etiologies remain elusive and the potential for differential diagnosis is considerable. The present study was therefore designed to compare clinical nonspecific symptoms associated with these pathologies and basic changes in free radical and amino-acid metabolism. Nineteen males were examined at rest and after maximal exercise at sea level before (SL(1)/SL(2)) and following a 20 +/- 5 day ascent to Kanchenjunga base camp located at 5100 m (HA).