Preliminary Observations on Skeletal Muscle Adaptation and Plasticity in Homer 2 Mice.

Homer represents a diversified family of scaffold and transduction proteins made up of several isoforms. Here, we present preliminary observations on skeletal muscle adaptation and plasticity in a transgenic model of Homer 2 mouse using a multifaceted approach entailing morphometry, quantitative RT-PCR (Reverse Transcription PCR), confocal immunofluorescence, and electrophysiology. Morphometry shows that muscle (SOL), at variance with muscle (EDL) and muscle (FDB), displays sizable reduction of fibre cross-sectional area compared to the WT counterparts.

Whey protein with potassium bicarbonate supplement attenuates the reduction in muscle oxidative capacity during 19 days of bed rest.

The effectiveness of whey protein plus potassium bicarbonate-enriched diet (WP+KHCO) in mitigating disuse-induced changes in muscle fiber oxidative capacity and capillarization was investigated in a 21-day crossover design bed rest study. Ten healthy men (31 ± 6 yr) once received WP+KHCO and once received a standardized isocaloric diet. Muscle biopsies were taken 2 days before and during the 19th day of bed rest (BR) from the soleus (SOL) and vastus lateralis (VL) muscle.

Increased myofiber remodelling and NFATc1-myonuclear translocation in rat postural skeletal muscle after experimental vestibular deafferentation.

Background: The vestibular system undergoes considerable modification during spaceflight [5]. This is paralleled by microgravity-induced muscle atrophy [6]. However, the possibility of vestibulo-autonomic regulatory mechanisms affecting skeletal muscle structure and function have not yet been addressed.

Nitrosative stress in human skeletal muscle attenuated by exercise countermeasure after chronic disuse.

Activity-induced nitric oxide (NO) imbalance and "nitrosative stress" are proposed mechanisms of disrupted Ca(2+) homeostasis in atrophic skeletal muscle. We thus mapped S-nitrosylated (SNO) functional muscle proteins in healthy male subjects in a long-term bed rest study (BBR2-2 Study) without and with exercise as countermeasure in order to assess (i) the negative effects of chronic muscle disuse by nitrosative stress, (ii) to test for possible attenuation by exercise countermeasure in bed rest and (iii) to identify new NO target proteins. Muscle biopsies from calf soleus and hip vastus lateralis were harvested at start (Pre) and at end (End) from a bed rest disuse control group (CTR, n=9) and two bed rest resistive exercise groups either without (RE, n=7) or with superimposed vibration stimuli (RVE, n=7).

Homer protein family regulation in skeletal muscle and neuromuscular adaptation.

Scaffolding adaptor proteins of the Homer family have recently been implicated in regulation of a large number of physiological processes owing to their remarkable ability to coordinate a complex network of different molecular players within the same signaling pathway. However, because of their unique molecular properties that also allow functional modulation of a plethora of different interacting protein partners, Homers seem to play additional and important roles in the integration of several molecular players belonging to different signaling pathways and thus allowing crosstalk. The role of the Homer protein family has been previously extensively investigated in neuronal tissue where it was first discovered as a new protein family being upregulated in response to brain seizures (Brakeman P.

Cardiac markers (BNP, NT-pro-BNP, Troponin I, Troponin T, in female amateur runners before and up until three days after a marathon.

Purpose: Transient cardiac ventricular dysfunction or sudden cardiac deaths have been reported for male athletes participating in marathon racing. Less is known about the myocardial response in females. We examined natriuretic peptides and cardiac troponins in female athletes after a marathon.

Molecular biomarkers monitoring human skeletal muscle fibres and microvasculature following long-term bed rest with and without countermeasures.

The cellular mechanisms of human skeletal muscle adaptation to disuse are largely unknown. The aim of this study was to determine the morphological and biochemical changes of the lower limb soleus and vastus lateralis muscles following 60 days of head-down tilt bed rest in women with and without exercise countermeasure using molecular biomarkers monitoring functional cell compartments. Muscle biopsies were taken before (pre) and after bed rest (post) from a bed rest-only and a bed rest exercise group (n = 8, each).

Erythropoietin as a volume-regulating hormone: an integrated view.

The intravascular volume consists of 40% to 45% red cells. Their production is controlled predominantly by erythropoietin (EPO), a hormone that is secreted particularly when tissue hypoxia is present. Because of this high percentage of the total intravascular volume the question comes to mind that, in addition to hypoxia, can volume-regulation mechanisms, known to be responsible for the maintenance of plasma volume, modulate EPO secretion when the total vascular volume changes? Indeed, there is evidence that in situations in which the intravascular volume or specifically the intrathoracic volume is altered, EPO secretion is affected.