<div>To investigate the relationship between the energy strategies in response to food restriction and the levels of metabolism in small mammals, body mass, resting metabolic rate (RMR), nonshivering thermogenesis (NST) and cytochrome c oxidase (COX) activity were measured in Apodemus chevrieri that were subjected to different levels of food restriction (FR). The results showed that cold-exposed group had significantly increased RMR and NST, but decreased body mass and survival rate after being restricted to 80% of ad libitum food intake compared with their counterparts maintained at room temperature. A. chevrieri with higher RMR consumed higher food intake than individuals with lower RMR, whereas no differences were observed in body mass and survival rate between two groups after being restricted to 80% of ad libitum food intake. The results suggest that A. chevrieri characterized by higher levels of metabolism are sensitive to periods of FR, providing a support for the &ldquo;metabolism switch hypothesis&rdquo;.</div>


<div>Effects of food restriction on energy metabolism in male <em>Apodemus chevrieri</em> from Hengduan mountain region of China</div>


<div>Thermal stress is a unique and complex process which alters the normal physiological mechanisms. Heat shock proteins (HSPs) are known to be highly conserved and ubiquitous proteins synthesized in response to several stimuli. The HSP inducers have been categorized as environmental (heat shock, UV radiation, heavy metals, amino acids, oxidative stress, <em>etc</em>.) pathological (bacterial or parasitic infections, fever, inflammation, <em>etc</em>.) and physiological (growth factors, cell differentiation, hormonal stimulation or tissue development, caloric restriction, <em>etc</em>.). The HSPs play an important role for maintaining cellular functioning under environmental challenges and protein denaturation conditions. There is a great potential for using HSP72 expression to detect natural adaptation and exposure to stress in natural populations. Leptin is a 16 kDa polypeptide hormone secreted primarily from the cells of white adipose tissue. Leptin acts through both central and peripheral mechanisms to affect feeding behaviour, lipid and glucose metabolism, thermogenesis, reproductive and endocrine functions. Leptin also plays an important role in the regulation of body weight and composition, <em>e.g</em>. reduction in feed intake and increase in energy expenditure. Bovine lymphocytes express Ob-Rb gene (leptin receptor) and also express leptin. There are ample information on the central role of leptin in brain and neural tissue regulation. In dairy cattle, the increase in milk yield has been associated with a negative energy balance and a decrease in fertility during early lactation. The hormone leptin is involved in regulation of nutritional status and reproductive function.</div>


Effects of food restriction on energy metabolism in male Apodemus chevrieri from Hengduan mountain region of China

Role of HSP and Leptin in Dairy Animals during Thermal Stress: A Review