Trp64Arg Polymorphism in Beta3-Adrenergic Receptor Gene Is Associated with Decreased Fat Oxidation Both in Resting and Aerobic Exercise in the Japanese Male

The purpose of our study was to investigate whether the Trp64Arg polymorphism in β3-AR gene and the −3826A/G polymorphism in the UCP1 gene were associated with the reduction in energy expenditure and fat oxidation both in resting and aerobic exercise in Japanese. Eighty-six nonobese young healthy Japanese were recruited. Energy expenditure was measured using indirect calorimetry. The subjects performed an aerobic exercise program at 60% of their maximal heart rate for 30 minutes. The level of fat oxidation at rest and aerobic exercise of the male subjects with Trp/Arg of the β3-AR gene was significantly lower than that of the Trp/Trp genotype. No difference in FO0−30 was observed in the female subjects. There was no association between UCP-1 polymorphism and energy expenditure during aerobic exercise. It was revealed that the Trp64Arg polymorphism in β3-AR gene is associated with reduction of fat oxidation both in resting and aerobic exercise in healthy, young Japanese males

Hypophosphatemia occurs with insulin administration during refeeding by total parenteral nutrition in rats

Refeeding syndrome (RFS) is characterized by the metabolic and clinical changes that occur following aggressive nutritional supplementation in malnourished patients. Hypophosphatemia is the hallmark of RFS and is key to its prevention and treatment in clinical practice. However, the mechanism of hypophosphatemia during RFS is unclear because of the lack of an animal model. In this study,we developed a rat RFS model as a first step to clarifying the molecular mechanism. After establishing the parenteral route, rats were fasted for 5 days and refeeding was started using total parenteral nutrition. The animals were infused with a high calorie solution with or without insulin administration. Results showed that plasma phosphate levels did not decrease in rats infused with the high calorie solution alone ; in contrast, a 20% reduction compared to baseline was observed in rats administered insulin. In addition, rats infused with the high calorie solution containing added phosphate did not present with hypophosphatemia. Thus, we developed a rat RFS model with hypophosphatemia by tube feeding and insulin administration, and demonstrated the importance of phosphate in preventing refeeding hypophosphatemia