Orexins对小鼠摄食和能量代谢的影响

目的:探讨Orexins对小鼠摄食和能量代谢的影响。方法:将小鼠分为摄食组和代谢组,摄食组通过中枢置管,注射不同剂量(1、3、10 nmol)的orexin-A和orexin-B,观察它们对小鼠摄食以及肝柠檬酸合酶活性的影响。代谢组将小鼠置于代谢笼内,通过中枢注射orexin-A,观察小鼠在光照条件、黑暗条件、禁食条件下呼吸商和代谢率的变化。结果:与对照组相比,1 nmol和10 nmol orexin-A在注射后4小时内可显著刺激小鼠进食(P0.05),而3 nmol orexin-A对摄食量的影响并不明显,但能显著促进柠檬酸合酶活性。任何剂量的orexin-B对小鼠摄食都没有显示出刺激作用(P0.05)。在光照条件下,orexin-A可显著降低呼吸商(RQ),代谢率显著升高(P0.05);而在黑暗条件下,orexin-A对RQ没有任何影响,但代谢率显著升高(P0.05);但是给禁食小鼠中注射orexin-A可诱导RQ的短暂升高,代谢率显著升高(P0.05)。结论:Orexins对小鼠摄食与能量代谢可能有一定的调控作用。

Effects of Orexins on Feeding and Energy Metabolism in Mice

ABSTRACT Objective: To investigate the effects of Orexin peptides on feeding and energy metabolism in mice. Methods: The mice were divided into two groups: feeding 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.