The Role Of AMPK Signaling Pathway In Body Mass Regulation In Eothenomys Miletus Between Kunming And Dali Regions Under Food Restriction Or Fasting

Phenotypic plasticity of animal physiological characteristics is an important survival strategy to cope with environmental changes.There are regional differences in physiological adaptation strategies of the same species distributed in different regions.Small mammals need to adopt different life history strategies to cope with changes in environment and food.Among them,body mass regulation is a very important strategy,while ghrelin,leptin,AMP-activated protein kinase(AMPK)pathway activated by adenosine monophosphate(AMP)and hypothalamic appetite regulating neuropeptide are important indicators of body mass regulation.The previous study of our research group showed that the physiological differentiation of Eothenomys miletus in different regions has occurred under the conditions of short-term fasting and random food restriction.The body mass,resting metabolic rate(RMR),serum leptin and hypothalamic neuropeptide have phenotypic plasticity.In order to discuss the role of ghrelin,leptin and AMPK signaling pathway in the regulation of body mass,this study of E.miletus measured the thermogenic characteristics and related physiological indexes of AMPK signaling pathway in Kunming and Dali after food restriction and refeeding,fasting and refeeding.It mainly includes two parts:(1)The role of AMPK signaling pathway of E.miletus in body mass regulation in Kunming and Dali under food restrictionIn the re-feeding experiment after 80% food restriction,first of all,the food shortage and region have a significant impact on the body mass,RMR,hypothalamic neuropeptide expression,hormones and enzyme activity of ghrelin,leptin,AMPK signal pathway in the serum of E.miletus,and the food restriction will reduce the body mass,RMR The content of opioid melanocortin(POMC),cocaine-and-amphetamine-regulated transcriptional peptide(CART),leptin and its receptor expression,as well as the expression of Malonyl-Co A and carnitine palmitoyl transferase 1(CPT-1).However,the content of ghrelin and AMPK activity were increased.There was no difference in body mass,RMR,food intake and physiological indexes of E.miletus between Kunming and Dali and the control group after refeeding.Secondly,in serum and stomach,ghrelin was significantly positively correlated with the expression of neuropeptide Y(NPY)and Agouti-related protein(Ag RP)and AMPK activity,and negatively correlated with body mass,RMR,the expression of neuropeptide POMC and CART,as well as the activity of Malonyl-COA and CPT-1.leptin in serum showed a significant correlation with ghrelin.Thirdly,various physiological indicators also showed regional differences.For example,the RMR,NYP expression,Ag RP expression and CPT-1 activity of E.miletus in Kunming changed more significantly under food restriction,while the body mass,POMC content,CART expression,stomach ghrelin content,serum ghrelin content,serum leptin content,AMPK activity and Malonyl-Co A activity of E.miletus in Dali changed more significantly.Under food restriction,the AMPK signal pathway of ghrelin and leptin binding in the hypothalamus may play a role in body mass regulation.In addition,the regional differences of physiological indicators under food restriction may be related to the different temperatures or food resources in different regions,and the E.miletus in Dali are more sensitive to the changes of environmental resources.(2)The role of AMPK signaling pathway of E.miletus in body mass regulation in Kunming and Dali under fasting conditionsIn the re-feeding experiment after fasting for 10 hours,first of all,fasting and region have a significant impact on the body mass,RMR,hypothalamic neuropeptide expression,hormones and enzyme activity in the signal pathway of ghrelin,leptin and AMPK in the serum of the rats,and fasting will reduce the weight,RMR,POMC,CART,leptin content and its receptor expression,as well as the expression of Malonyl-Co A and CPT-1 in E.miletus,However,the content of ghrelin and AMPK activity were increased.There was no difference in body mass,RMR,food intake and physiological indexes of E.miletus between Kunming and Dali and the control group after refeeding.The results of correlation analysis showed that ghrelin in serum and stomach was significantly positively correlated with the expression of NPY,Ag RP and AMPK activity,and negatively correlated with body mass,RMR,the expression of POMC and CART,as well as the activity of Malonyl-COA and CPT-1.Leptin in serum showed a significant correlation with ghrelin.Through the analysis of regional differences of various indicators,it was found that various physiological indicators also showed regional differences.For example,the RMR,NYP expression,leptin content,and Malonyl-Co A activity and CPT-1 activity of E.miletus in Kunming changed more significantly,while the body mass,Ag RP content,POMC content,CART expression,gastric ghrelin content,and serum ghrelin content of E.miletus in Dali changed more significantly.In short,the overall change trend in Dali is more significant under fasting conditions,indicating that the E.miletus in Dali are more sensitive to short-term environmental changes.The results showed that the body mass,RMR,the content of the inhibitory neuropeptides POMC and CART,the content of leptin and its receptor expression,and the expression of Malonyl-Co A and CPT-1 were decreased,but the content of ghrelin and its receptor expression and AMPK activity were increased.There was no difference in body mass,RMR,food intake and physiological indexes of E.miletus between Kunming and Dali and the control group after refeeding.In serum and stomach,ghrelin was significantly positively correlated with the expression of NPY and Ag RP and AMPK activity,and negatively correlated with body mass,RMR,the expression of POMC and CART,and the activity of Malonyl-COA and CPT-1.Leptin in serum showed a significant correlation with ghrelin.Each physiological index also shows regional differences.Regardless of food restriction or fasting,the overall change range of each index in Dali is greater than that in Kunming,and Dali is more sensitive.The above results indicate that food restriction or fasting can reduce the energy metabolism of E.miletus.Among them,body mass,ghrelin content and AMPK activity play an important role in their survival and adaptation.After refeeding,the relevant physiological indicators can return to the level of the control group,indicating that the E.miletus have strong phenotypic plasticity,indicating that leptin,ghrelin and AMPK pathways play an important role in the cell energy metabolism and adaptation under the condition of food shortage.In addition,the regional differences of physiological indexes under the conditions of food restriction or fasting may be related to the differences in the temperature and food of the habitat environment of E.miletus in different regions.