Evidence of weight loss in junior female judo athletes affects their development.

Purpose: The facile manipulation of body weight in junior athletes has the potential to pose significant risks to their lifelong health. In judo, which is a weight class sport, pre-competition weight loss is widespread even among juniors, but information on the current situation is scarce, especially for female athletes, for whom it is important to provide adequate nutrition and enhance bone mass during the growth period, and the details of the current situation are not clear. Therefore, the purpose of this study was to determine the actual weight loss during the growth period in junior female judo athletes and its subsequent impact on their health.

The Molecular Mechanism Underlying Continuous Exercise Training-Induced Adaptive Changes of Lipolysis in White Adipose Cells.

Physical exercise accelerates the mobilization of free fatty acids from white adipocytes to provide fuel for energy. This happens in several tissues and helps to regulate a whole-body state of metabolism. Under these conditions, the hydrolysis of triacylglycerol (TG) that is found in white adipocytes is known to be augmented via the activation of these lipolytic events, which is referred to as the "lipolytic cascade.

Role of nitric oxide in muscle regeneration following eccentric muscle contractions in rat skeletal muscle.

We examined the role of nitric oxide (NO) in muscle repair and regeneration following repetitive eccentric contractions (ECC). A standardized exercise protocol was used to create eccentric contraction-induced injury to the left tibialis anterior muscle of 48 male Wistar rats (body wt 250-350 g), using a customized isokinetic test device and a bout of 40 ECCs under electrical stimulation. A nitric oxide synthase inhibitor, N(G)-nitro-L-arginine-methyl ester (L-NAME; 35 mg kg(-1) day(-1)), was included in the diet for half the animals (n = 24) beginning 3 days prior to the ECC and continuing throughout the experiment, whereas the other half (n = 24) received a control diet.

Beta-adrenergic receptor trafficking by exercise in rat adipocytes: roles of G-protein-coupled receptor kinase-2, beta-arrestin-2, and the ubiquitin-proteasome pathway.

The effect of exercise on beta-adrenergic receptor (beta-AR) trafficking was investigated in rat adipocytes. The binding sites of a hydrophilic ligand, [(3)H]CGP12177, increased immediately (0 h) and at 3 h after exercise (3 h) but decreased at 24 h after exercise (24 h). The data of immunoblotting revealed that the alterations in the binding sites mainly paralleled the alterations in the beta2-AR proteins in membrane fractions.

Exercise training enhances tumor necrosis factor-alpha-induced expressions of anti-apoptotic genes without alterations in caspase-3 activity in rat epididymal adipocytes.

The effect of exercise training on tumor necrosis factor-alpha (TNF-alpha) signaling was investigated in rat epididymal adipocytes. Incubation of isolated adipocytes with TNF-alpha (20 ng/ml) for 5 h enhanced the expression of the inhibitor apoptosis protein 2 (IAP2) gene without any enhancement of caspase-3 activity in both the sedentary control (C) and exercise-trained (TR) groups. However, the ability of TNF-alpha to enhance IAP2 gene expression was significantly greater in TR than in C rats.

Changes in nitric oxide and inducible nitric oxide synthase following stretch-induced injury to the tibialis anterior muscle of rabbit.

This study investigated the changes in nitric oxide (NO) together with inducible nitric oxide synthase (iNOS) content and enzyme activity at 0, 4, 12, 24, and 48 h following acute muscle stretch injury. A single stretch injury was induced to the tibialis anterior muscle of 30 male New Zealand white rabbits (n = 6 at each time point). Injured and uninjured contralateral sham-operated muscles were harvested and analyzed for NO levels, iNOS content, and iNOS activity at each time point.

Desensitization of the inhibitory effect of norepinephrine on insulin secretion from pancreatic islets of exercise-trained rats.

The effect of exercise training (9 weeks of running) on norepinephrine-induced inhibition of insulin secretion was examined in rat islets. Insulin secretions from islets in the presence of glucose (> or =5.5 mmol/L) were significantly lower in trained (TR) than in control rats (CR).

Enhanced expression of neuronal nitric oxide synthase in islets of exercise-trained rats.

It is well known that glucose-stimulated insulin secretion (GSIS) decreases after exercise training. In the present study, we investigated the effects of exercise training (9 weeks of running) on the activity of glucokinase (GK), the production of nitric oxide (NO), and the protein expressions of both glucose transporter-2 (GLUT-2) and NO synthase (NOS) in rat pancreatic islets. Exercise training significantly reduced GSIS, with decreases in GK activity and GLUT-2 protein expression.

Possible role of nitric oxide on adipocyte lipolysis in exercise-trained rats.

A possible role of nitric oxide (NO) on adipocyte lipolysis was studied in exercise-trained (9 weeks of running) rats. Lipolysis in adipose tissue tended to be greater in trained rats than in control rats. A treatment of adipose tissue with 5 mM N(G)-nitro-L-arginine methyl ester (L-NAME) showed that basal and isoproterenol-stimulated lipolysis were both significantly greater in trained rats than in control rats.