Effects of Orexins on Feeding and Energy Metabolism in Mice / 现代生物医学进展

ABSTRACT

Objective:To investigate the effects of Orexin peptides on feeding and energy metabolism in mice.Methods:The mice were divided into two groupsfeeding group and metabolic group.The feeding group were injected with different doses (1,3 and 10 nmol) of orexin-A and orexin-B to observe their effects on feeding and the activity of tyrosine hydroxylase in liver.We used the metabolic cages and observed the changes of respiration rate and respiration rate of mice were under light condition,dark condition and fasting condition.Results:Compared with the control group,1 nmol and 10 nmol orexin-A significantly stimulated mice to feed (P ＜0.05) within 4 hours after injection,and the effect of 3 nmol orexin-A on feeding was not obvious,but increase the activity of tyrosine hydroxylase.Any dose of orexin-B did not show a stimulating effect on mice feeding.(P ＞0.05).In the light cycle,orexin-A could significantly reduce the respiration rate (RQ),the metabolic rate was significantly increased (P ＜0.05);In the dark cycle,orexin-A had no effect on RQ,but the metabolic rate was significantly rised (P ＜0.05);But the injection of orexin-A in fasting mice induced a brief increase in RQ and a significant increase in metabolic rate (P ＜0.05).Conclusion:Orexins may play an important role in regulating feeding and energy metabolism in mice.