Metabolic profile and spontaneous physical activity modulation under short-term food restriction in young rats.

Abstract

-Aims: The aim of this study was to investigate the effects of short-term food restriction (6-weeks) on metabolic profile and spontaneous physical activity (SPA) of young male Wistar rats. Methods: Thirty rats had their baseline SPA measured at 21 days-old and were separated into two groups at 28 days-old: Control (CG) and 50% of food restriction (FR). The food restriction protocol lasted six weeks, being the SPA measured weekly by a gravimetric apparatus. At the end of the experiment, biochemical analyses were performed in serum and tissue samples with statistical significance set at 5%. Results: FR showed less SPA than CG, as occurred for body mass, water intake, adipose tissue and liver, heart and soleus glycogen, serum glucose, total protein, triglycerides and total cholesterol (P<0.05). Conclusion: Data set demonstrates that low substrate stores signaled to decrease spontaneous physical activity to save energy.

Moderate intensity swimming training on bone mineral density preservation under food restriction in female rats

“…Over 12 weeks, it was possible to demonstrate a reduction of body mass in animals submitted to FR of 20%, as expected, corroborating with other studies such as Aikawa et al 8 , Beck et al 37 and Yanaka et al 26 who applied a more intense protocol than our, using 30%, 50%, and 30%, respectively. It is known the relationship between body mass reduction and BMD reduction 10,14 , possibly because it exerted less impact with the consequent decrease of the piezoelectric effect 19 , which could explain FR result regarding BMD.…”

“…In addition, the lower energetic flux is noticeable to the sympathetic nervous system and may have as consequence a reduction of insulin and thyroid hormones secretion. These hormonal changes decrease the cellular metabolic rate to save energy, inducing a reduction in spontaneous physical activity 37 . It may also reflect in a greater expression of PPARy in mesenchymal stem cells and receptor activator of nuclear kappa-B ligand (RANKL), stimulating bone resorption by osteoclasts 10,11 .…”

Effects of high-intensity interval training in more or less active mice on biomechanical, biophysical and biochemical bone parameters

“…SPA was measured by the gravimetric method 27 , according to the activities produced by the animals that generated a force on the platform, recorded by load cells capable of identifying them as weight changes on the structure. The gravimetric principle has been used successfully on many studies involving animal models 22,[28][29][30][31][32] . In each housing condition (SC and LC), we used three load cells of similar design (MKPM, MK Controle e Instrumentação, BR) 22 .…”

Effects of Moderate–Intensity Physical Training on Skeletal Muscle Substrate Transporters and Metabolic Parameters of Ovariectomized Rats

“…Spontaneous physical activity was measured biweekly using the gravimetric principle which has been employed by many investigators [ 56 , 57 , 58 , 59 , 60 , 61 ]. The principle of gravimetric apparatus is that movements generated by rats induce a force on the platform that can be quantified by load cells (MKPW ® , MK Control and Instrumentation™, São Paulo, Brazil) as a change in weight.…”