Effects Of Lha Orexin-A On Basal Metabolism,Spontaneous Activity And Feeding In Mice And Regulation Of Cannabinoid Receptor Signaling Pathway

Objective: Orexin-A,also known as Leptin,is closely related to the initiation of feeding.It can achieve its feeding-promoting effect by activating the network loop between multiple nuclear groups in the hypothalamus.It has been reported that the orexins system can participate in regulating the body’s energy metabolism.Another important system in which the central body participates in regulating food intake is the endocannabinoid system(ECBS),which is another important target for the study of obesity treatment.Endocannabinoids(ECB)can participate in the regulation of energy metabolism and feeding activities by acting on the cannabinoid 1 receptor(CB-1R).CB-1R antagonist AM251 was injected intraperitoneally in mice,and the expression of orexin-A in ventral tegmental area(VTA)was significantly increased.However,whether the ECB and CB-1R signaling pathways are involved in orexin-A regulation of energy metabolism and food intake in mice has not been reported.This study intends to observe the effects of LHA injection orexin-A on basal metabolism,spontaneous activity and food intake in mice,and to explore the regulation of orexin-A by the inhibition or activation of cannabinoid signaling pathways in order to complement and improve orexin central participation The theory of energy balance regulation provides credible experimental basis for the prevention and treatment of metabolic disorders such as clinical obesity.Methods: 1.Male Kun Ming(KM)mice were randomly selected and placed in the lateral ventricle and/or LHA by reference to the mouse brain map using a brain nucleus tube.2.The effect of LHA microinjection of orexin-A on the basic and resting metabolism of mice and the regulation of cannabinoid receptor signaling pathway.The effects of preinjection of Rim in the lateral ventricle(icv),injection of re-orexin-A in LHA,or injection of THC,orexin-A or THC+ orexin-A in LHA on BMR and RMR in mice were observed.3.The effect of LHA microinjection of orexin-A on the spontaneous activity of mice and the regulation of cannabinoid receptor signaling pathway.4.The effect of LHA microinjection of orexin-A on the feeding of mice and the regulation of cannabinoid receptor signaling pathway.After injection,the changes of normal feed intake and delicious food intake of peanut butter granules were observed.Results: 1.The effect of LHA microinjection of orexin-A on the basic and resting metabolism of mice and the regulation of cannabinoid receptor signaling pathway showed that compared with DMSO group,LHA microinjection of orexin-A,basal metabolic rate of mice(P < 0.05~0.01)and resting metabolic rate(P < 0.05 ~ 0.01)were significantly increased,and increased in a dose-dependent manner.Compared with the NS control group,the lateral ventricle was injected with the cannabinoid 1 receptor antagonist rimonabant(Rim,2 μg / 2 μl),the basal metabolic rate(BMR,P < 0.05)and resting metabolic rate(RMR,P < 0.05)was significantly reduced.Conversely,if LHA was injected with the cannabinoid receptor agonist tetrahydrocannabinol(THC,0.5 μg/0.5 μL),the basal metabolic rate(BMR,P < 0.05)and resting metabolic rate(RMR,P < 0.05)were evident in mice increased.This study further investigated the effects of cannabinoid receptor signaling pathway repression or activation on energy metabolism in LHA orexin-A-mediated mice.The results showed that compared with the NSicv+DMSOLHA group,LHA was injected with 1.0 μg orexin-A(NSicv+ orexin-A LHA),and the basal metabolic rate(P < 0.05)and resting metabolic rate(P < 0.05)were significantly increased.Compared with the NSicv+ orexinA LHA group,if the lateral ventricle was pre-injected with Rim,LHA was injected with orexin-A(Rimicv+ orexin-ALHA),orexin-A increased basal metabolic rate(P < 0.05)or resting metabolic rate(P < 0.05)is significantly weakened.If LHA was injected with THC,orexin-A and a mixture of THC and orexin-A,the basal metabolic rate(P < 0.05)or resting metabolic rate(P < 0.05)of the mice increased significantly.In order to observe whether THC and orexin-A synergistically promote energy metabolism in mice,this study further analyzed the effect of LHA injection of THC+orexin-A mixture on energy metabolism in mice.Metabolic growth rate analysis showed that compared with the sum of orexin-A LHA metabolic growth rate and THC LHA metabolic growth rate,LHA injected THC+orexin-A mixture,mouse BMR growth rate(P < 0.05)or RMR growth rate(P < 0.05)both increased significantly.2.The effect of LHA microinjection of orexin-A on spontaneous activity in mice and the regulation of cannabinoid receptor signaling pathway showed that compared with DMSO group,LHA microinjection of orexin-A significantly increased spontaneous activity in mice,showing activity per unit time.The distance increased significantly and increased in a dosedependent manner(P < 0.05~0.01);Compared with the NS control group,the lateral ventricle was injected with the cannabinoid 1 receptor antagonist Rim(2μg/2μl),and the spontaneous activity of the mice was significantly reduced,which showed a significant decrease in the activity distance per unit time(P < 0.05).In contrast,if LHA was injected with the cannabinoid receptor agonist THC(0.5 μg/0.5 μL),the activity distance per unit time of the mice increased significantly(P < 0.05).This study further observed the effect of cannabinoid receptor signaling pathway repression or activation on the spontaneous activity of LHA orexin-A-regulated mice.The results showed that compared with the NSicv+DMSOLHA group,LHA was injected with 1.0 μg of orexin-A(NSicv+ orexin-A LHA),and the spontaneous activity of the mice was significantly increased(P < 0.05).Compared with the NSicv+ orexin-A LHA group,if the lateral ventricle was pre-injected with Rim and LHA was injected with orexin-A(Rimicv+ orexinALHA),orexin-A induced a significant decrease in spontaneous activity in mice(P < 0.05).If LHA was injected with THC,orexin-A,and THC and orexin-A,the activity distance of the mice increased significantly(P < 0.05).In order to observe whether THC and orexin-A synergistically promote energy metabolism in mice,this study further analyzed the effect of LHA injection of THC +orexin-A mixture on spontaneous activity in mice.The results of spontaneous activity growth rate analysis showed that there was no significant difference in the rate of spontaneous activity of mice between the LHA injection of THC+orexin-A mixture and the growth rate of spontaneous activity of orexin-ALHA and the growth rate of spontaneous activity of THCLHA(P > 0.05).3.The effect of LHA microinjection of orexin-A on 0-2h selective feeding and regulation of cannabinoid receptor signaling pathway in mice showed that compared with DMSO group,LHA microinjected orexin-A,mice to normal feed(P <0.05~0.01)and peanut butter pellet feed(P < 0.05)0-2h intake increased significantly,especially in the dose-dependent increase of normal feed intake(P < 0.05 ~ 0.01).Compared with the NS control group,the lateral ventricle was injected with the cannabinoid 1 receptor antagonist Rim(2 μg / 2 μl),and the mice were ingested for 0-2 h in normal feed(P < 0.05)and peanut butter pellets(P < 0.05).Significantly lower.Conversely,if LHA was injected with the cannabinoid receptor agonist THC(0.5 μg/0.5 μL),the mice had a significant increase in 0-2 h intake to normal diet(P < 0.05)and peanut butter pellets(P < 0.05).However,there was no significant difference in the effect of Rim or THC on the increase or decrease of the intake of normal feed or peanut butter pellets in mice(P < 0.05).This study also observed the effect of cannabinoid receptor signaling pathway repression or activation on LHA orexin-A-regulated selective feeding in mice.The results showed that compared with the NSicv+DMSOLHA group,LHA was injected with 1.0 μg orexin-A (NSicv+ orexin-A LHA),and the mice were ingested for 0-2 h in normal diet(P < 0.05)and peanut butter pellets(P < 0.05).Significantly increased(P < 0.05)compared with the NSicv+ orexin-A LHA group,if the lateral ventricle was pre-injected with Rim,LHA was reinjected with orexin-A(Rimicv+ orexin-ALHA),and orexin-A promoted normal mouse feed(P < 0.05)or Peanut Butter pellet feed(P < 0.05)0-2h intake effect was significantly reduced.If LHA was injected with THC,orexin-A,and THC+orexin-A,the increase in orientin-A induced normal feed(P < 0.05)or peanut butter pellet(P < 0.05)was more significant.In order to observe whether THC and orexin-A promote synergy in mice,this study further analyzed the effect of LHA injection of THC+orexin-A mixture on feeding in mice.The results of the food intake growth rate showed that compared with the sum of the orexin-A LHA feeding rate and the THC LHA feeding rate,the LHA injection of THC+orexin-A mixture,the normal feed growth rate of mice(P > 0.05)or the growth rate of peanut butter pellets.(P > 0.05)No significant difference.Conclusions: LHA Orexin-A dose-dependently promotes basal energy metabolism in mice,increases spontaneous activity and feeding in mice,and cannabinoid receptor signaling system activity(activation or repression)is involved in the regulation of this process,and LHA orexin-A and THC Synergistic to the above process.