Differential associations between white blood cell counts and fatigue in young and older adults.

Background And Aims: The aims of this exploratory study were to study whether fatigue might be related to the cellular immune system by 1) analysing if the number of white blood cell subsets are related to fatigue and 2) if possible relationships vary in younger and older community-dwelling individuals.

Methods: The participants were recruited from nine general practitioners in Aarhus County, Denmark and included 196 individuals aged 20-35 years and 314 individuals aged 70-85 years. The white blood cell counts included number of total leukocytes, lymphocytes, monocytes, neutrophils, eosinophils, and basophils.

Interaction between exercise, dietary restriction and age-related bone loss in a rodent model of male senile osteoporosis.

Background: The pathophysiology of age-related bone loss and whether age-related bone loss can be prevented by exercise are still a matter of debate.

Objective: It was the aim of this study to investigate the long-term effects of exercise and mild food restriction on bone mineral density (BMD) and bone geometry in the appendicular skeleton of aging male rats.

Methods: Male Sprague-Dawley rats were studied from 5 to 23 months of age.

Decline of bone marrow-derived hematopoietic progenitor cell quality during aging in the rat.

Several studies have shown that aging is associated with quantitative and qualitative alterations of the stem and progenitor cell compartment. The current results indicate that there is a significant age-associated decline in the proliferative capacity of rat myeloid progenitor cells. In contrast, no difference was found in the frequency of myeloid progenitor cells in the bone marrow of young versus old rats.

Physical functioning and use of health services in a young and old sample. The influence of fatigue.

Introduction: The purpose was to analyse 1) whether fatigue is related to physical functioning and utilization of health services at one-year follow-up in a young and old sample and 2) to compare the results of two different measures of fatigue.

Methodology: The study is a longitudinal cohort study based on 182 young (age 20-35) and 199 older (age 70-85) community-dwelling individuals recruited from nine general practitioners in Aarhus, Denmark. Physical functioning was measured by the physical health scale from the SF-12-questionnaire.

Hippocampal metabolic proteins are modulated in voluntary and treadmill exercise rats.

Systematic protein expression studies in the brain of exercising and sedentary animals have not been carried out so far and it was therefore decided to determine differences in metabolic protein levels in rat hippocampus of sedentary, voluntary and involuntary exercising rats by a proteomic approach. Aged, male Sprague-Dawley rats, 23 months old, were used for the study: the first group consisted of sedentary rats, the second of rats with voluntary exercise from five to 23 months and the third group was performing involuntary exercise on a treadmill from five to 23 months. Two-dimensional gel electrophoresis with subsequent mass spectrometrical identification of spots followed by quantification of spots was carried out.

Running has a negative effect on bone metabolism and proinflammatory status in male aged rats.

Animal models for male osteoporosis are scarce. This study aimed at identifying the impact of different living conditions on bone structure and metabolism as well as the inflammatory status in a rat model of age-related male osteoporosis. Bone mineral density, bone histomorphometric data, ex vivo osteoclast generation, and bone metabolism serum marker as well as intracellular cytokine expressions were evaluated in 23-month-old male Sprague-Dawley rats subjected to different housing conditions from the age of 5 months.

Modulation of the hippocampal protein machinery in voluntary and treadmill exercising rats.

Information about protein expression studies in the brain of exercising and sedentary animals is limited. Cognitive functions change during exercise and the aim of this study was to investigate rat protein levels of the protein machinery in the hippocampus, the main cognitive brain area for spatial learning and memory, in exercising rats. Protein fluctuations may reflect functional variation during exercise.

Influence of physical exercise and food restriction on the biomechanical properties of the femur of ageing male rats.

Background: Voluntary running in wheels as well as food reduction increase the life spans of rats. Disparate parameters such as the collagen biomarker of ageing and the development of kidney pathologies are decreased by voluntary exercise. There are few reports on the influence of physical exercise and food restriction on the skeleton of male rats.

Hippocampal signaling cascades are modulated in voluntary and treadmill exercise rats.

Systematic protein expression studies in the brain of exercising and sedentary animals have not been carried out for far. Signaling proteins are main structures regulating hippocampal function and we decided to determine differences in signaling protein levels in rat hippocampus by a proteomic approach. Aged, male Sprague-Dawley rats, 23 months old, were used for the study: the first group consisted of sedentary rats, the second of rats with voluntary exercise from 5 to 23 months and the third was performing involuntary exercise on a treadmill from 5 to 23 months.

Bone structure and metabolism in a rodent model of male senile osteoporosis.

Osteoporosis is a common and severe condition in elderly men, which is poorly characterized. In order to identify the hallmarks of age-related bone loss in the male mammalian skeleton, we studied several aspects of bone structure and metabolism in 23-month-old male Sprague-Dawley rats and compared them to 5-month-old animals. Cancellous bone mineral density, bone volume and trabecular number were markedly reduced in the proximal tibia of aged rats when compared to the young rats.

Norepinephrine treatment and aging lead to systemic and intracellular oxidative stress in rats.

Reactive oxygen species (ROS) play important roles in cellular senescence and organismic aging. Furthermore, they have been implicated in some of the adverse effects of chronic stress due to elevated peripheral levels of catecholamines. Here, we applied three different techniques to individually compare the systemic and intracellular oxidative stress in aged (23 months) and young (5 months) Sprague-Dawley rats, and in young rats treated for 12 or 24 h with norepinephrine (NE).

The impact of environment in comparison with moderate physical exercise and dietary restriction on BDNF in the cerebral parietotemporal cortex of aged Sprague-Dawley rats.

Background And Aims: Moderate physical exercise, dietary restriction as well as enriched environment in separate studies have been reported to delay some of the adverse effects of aging on brain function, parallel to an increase in brain-derived neurotrophic factor (BDNF). In order to elucidate these influences in a comparative setting, we examined the tissue concentrations of BDNF in the cerebral parietotemporal cortex of old Sprague-Dawley rats.

Methods: Male Sprague-Dawley rats were divided randomly into six groups, living from 5 months (baseline group BL) up to 23 months of age as follows: voluntary running in wheels (RW), food restricted by feeding to pair weight with RW animals (PW), forced running on treadmills (TM), and sedentary controls with ad libitum access to food, either housed individually (S1) or in groups of 4 animals (S4).