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The aim of this study was to evaluate the effects of an official Taekwondo competition on the heart rate (HR), salivary α-amylase (sA-A), salivary free cortisol (sC), and Profile of Mood States (POMS) in 10 young male (14±0 years) and six female (13±1 years) athletes. POMS and hormones were measured 15 min before and directly after the competition. During the recovery phase (30 and 90 min), sA-A and sC were also measured. HR measured during the competition was expressed as a percentage of individual's maximal heart rate (%HR) to evaluate the intensity of exercise. During the competition, athletes spent 65% of the time working at HR>90% of individuals HR. A significant increase ( P<0.0001) in sA-A (115%) was observed at the end of the match. At 30 min of recovery, sA-A returned to the pre-competition level. The peak sC values were observed at 30 min of recovery ( P<0.001), returning to the pre-competition level at 90 min of recovery. A gender difference ( P=0.01) emerged only for sC, although a similar trend was observed for female and male athletes. Significantly higher post-match scores emerged for Anger-hostility (pre: 6.1±1.1, post: 11.2±1.9; P=0.03) and Depression-dejection (pre: 4.5±0.5, post: 10.2±1.9; P=0.006), whereas the reverse picture was observed for Vigour-activity (pre: 23.2±1.2, post: 16.3±1.7; P=0.0006). Taekwondo competition results in temporary changes in the stress-related parameters measured in this study. The present findings suggest that this experimental paradigm can represent a useful model for further research on the effects of various stressors (i.e., training and competition) in Taekwondo athletes of different levels (i.e., novice, international). [ABSTRACT FROM AUTHOR]

Many environmental signals, including ionizing radiation and UV rays, induce activation of Egr-1 gene, thus affecting cell growth and apoptosis. The paucity and the controversial knowledge about the effect of electromagnetic fields (EMF) exposure of nerve cells prompted us to investigate the bioeffects of radiofrequency (RF) radiation on SH-SY5Y neuroblastoma cells. The effect of a modulated RF field of 900 MHz, generated by a wire patch cell (WPC) antenna exposure system on Egr-1 gene expression, was studied as a function of time. Short-term exposures induced a transient increase in Egr-1 mRNA level paralleled with activation of the MAPK subtypes ERK1/2 and SAPK/JNK. The effects of RF radiations on cell growth rate and apoptosis were also studied. Exposure to RF radiation had an anti-proliferative activity in SH-SY5Y cells with a significant effect observed at 24 h. RF radiation impaired cell cycle progression, reaching a significant G2-M arrest. In addition, the appearance of the sub-G1 peak, a hallmark of apoptosis, was highlighted after a 24-h exposure, together with a significant decrease in mRNA levels of Bcl-2 and survivin genes, both interfering with signaling between G2-M arrest and apoptosis. Our results provide evidence that exposure to a 900 MHz-modulated RF radiation affect both Egr-1 gene expression and cell regulatory functions, involving apoptosis inhibitors like Bcl-2 and survivin, thus providing important insights into a potentially broad mechanism for controlling in vitro cell viability. J. Cell. Physiol. 213:759–767. © 2007 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

Corticotropin-releasing factor (CRF), a neuropeptide of 41 amino acids, acts as the major physiological regulator of the basal and stress-induced release of corticotropin (ACTH), beta-endorphin and other proopiomelanocortin-derived peptides from the anterior pituitary gland. In addition to its endocrine activity, CRF displays extrahypophysiotropic effects, mainly as a regulator of stress responses. We show here that CRF may additionally function as a differentiating factor in immortalized noradrenergic neuronal CATH.a cells that express CRF receptor type I and resemble locus coeruleus-derived neurons. CRF triggers morphological changes in CATH.a cells including the appearance of extended long, slender neurites with prominent growth cones. CRF-treated CATH.a cells exhibit a morphology similar to locus coeruleus neurons in primary culture. CRF-induced neurite outgrowth of CATH.a cells was blocked by addition of inhibitors for cAMP-dependent protein kinase or extracellular signal-regulated protein kinase (ERK), a subtype of the mitogen-activated protein kinases. The participation of ERK within the CRF signalling cascade was further confirmed by Western blot experiments, with antibodies directed against the phosphorylated form of ERK, and also with transcription-based assays. We conclude that CRF functions as a differentiating factor of CATH.a cells via the cAMP and the MAP kinase signalling pathways.

The distribution and biochemical features of the synapsin-like peptides recognized in Aplysia and Helix by various antibodies directed against mammalian synapsins were studied. The peptides can be extracted at low pH and are digested by collagenase; further, they can be phosphorylated by both protein kinase A and Ca2+/calmodulin-dependent protein kinase II. In the ganglia of both snails, they are associated with the soma of most neurons and with the neuropil; punctate immunostaining is present along the neurites. Using cocultures of a Helix serotoninergic neuron and of its target cell, we analysed the redistribution of the synapsin-like peptides during the formation of active synaptic contacts. When the presynaptic neuron is plated in isolation, both synapsin and serotonin immunoreactivities are restricted to the distal axonal segments and to the growth cones; in the presence of the target, the formation of a chemical connection is accompanied by redistribution of the synapsin and serotonin immunoreactivities that concentrate in highly fluorescent round spots scattered along the newly grown neurites located close to the target cell. Almost every spot that is stained for serotonin is also positive for synapsin. In the presynaptic cell plated alone, the number of these varicosity-like structures is substantially stable throughout the whole period; by contrast, when the presynaptic cell synapses the target, their number increases progressively parallel to the increase in the mean amplitude of cumulative excitatory postsynaptic potentials recorded at the same times. The data indicate that mollusc synapsin-like peptides to some extent resemble their mammalian homologues, although they are not exclusively localized in nerve terminals and their expression strongly correlates with the formation of active synaptic contacts.