ABSTRACT
So far, juvenile rats take long-term exercise during development, changes of food intake and the mechanism of action of BDNF system in hypothalamus, all of the above is not yet clear.
2 MATERIALS AND METHODS
2.1 Experimental animals and grouping
Experimental animals are 10-week-old clean grade SD rats (Experimental Animal Center, Hebei Province, the permit number is SCXK ji 2008-1-003). We prepare pregnant rats based on preliminary scheme of research group (Jiao et al., 2012), and select three-week-old weanling male juvenile rats to do experiment. Rats are fed with clean water and national standard mixed feed and they freely drink water and eating food. Animals’ feed is provided by Experimental Animal Center, Hebei Province. In the laboratory, relative humidity is 50% ± 5% and temperature is controlled at 23 ± 2 °C in general,
1 INTRODUCTION
The relationship between exercise and food intake is complicated; based on a synthetic analysis, we find that different exercise intensity and duration can cause the phenomenon of suppressing appetite or promoting ingestion (Jiao et al., 2010). It is generally considered exercise below moderate intensity can stimulate food intake. The aim is to supply excessive consumption of energy during exercise, thus maintaining body weight. The hypothalamus is the center of body’s energy balance and the regulation of food intake. What’s more, it can secrete neuropeptide and neurotrophic factor which is mechanism to participate in the activities of food intake regulation. As for neuron, BDNF plays an important role in the process of growth, differentiation and maturation. And BDNF involves in learning, memory and a variety of behavior in Long-Term Potentiating (LTP) at the same time (Jo. 2012). In recent years, researchers found that BDNF in hypothalamus had central regulatory effect on food intake. According to the research, BDNF can cause weight loss and reduce food intake so that it is deemed to a sort of appetite-suppressing inhibitory factor. BDNF firstly composite pro-BDNF, by the hydrolysis of extracellular enzymes, such as matrix metalloproteinases and fibrinolytic enzyme, shearing become mature BDNF. Researches show that the BDNF and pro-BDNF in brain are regulated by growth
adopting natural sunlight. Rats are randomly divided into control group (C) and exercise group (E). Control group (C) doesn’t take any exercise while exercise group (E) take exercise once a day.
