CRF In "Hypothalamic-brain Stem-gut Axis" Involves In Restraint Water-immersion Stress

Restraint Water-Immersion Stress?RWIS?is a stimulating model that rapidly damages the brain and physiology of rats.In this stress model,rats are stimulated in a short period of time,body temperature drops,gastrointestinal dysfunction,resulting in increased gastric acid secretion and acute gastric mucosal damage.The enteric nervous system is a network of neurons,neurotransmitters and intestinal cells located in the wall of the gastrointestinal tract,which regulates and regulates the smooth muscle,mucosal epithelial and vascular effect systems in the gastrointestinal tract,and its regulation is highly autonomous.Also known as the"intestine brain."Early studies in our laboratory found that rats had hypothalamic paraventricular nucleus?PVN?and supraoptic nucleus with a period of restraint-immersion during a certain stress period.SON),nucleus of solitary tract?solitary nucleus,NTS?,dorsal vagal nucleus?dorsal motor nucleus of between the vagus,DMV?and intestinal myenteric plexus Fos and expression levels of GFAP?Glial Fibrillary Acidic Protein,GFAP?significantly liter High,we speculate that the restraint-immersion stress causes gastric mucosal damage not only involves the primary central mechanism of excessive activity of neurons in the brainstem^[75],so we propose the"hypothalamic-brain stem-gut axis"ring The road is involved in the regulation of stress.Corticotropin-Releasing Factor?CRF?,one of the most important hormones for the release of the paraventricular nucleus and supraoptic nucleus of the hypothalamus,has been shown to be involved in a variety of stresses?thermal stimulation,cold?.Stimulation,infection,and toxic stimulus response,but whether corticotropin releasing hormone?CRF?and its receptors are involved in the binding-immersion stress has not been reported.Therefore,we ask the following questions:1.Does CRF and its receptors mediate and participate in the RWIS process and how do they change over time in RWIS?2.What is the effect of the lateral ventricle injection of CRF receptor blockers Astressin and CRF on neurons and glial cells in the solitary tract nucleus and intestine?3.If the CRF participates in the process of binding-immersion,which signal path does it work through?In order to solve the above problems,our experimental design is as follows:Experimental study 1:Rats were randomly divided into control group?RWIS 0h?and stress group?RWIS 1h,RWIS 2h,RWIS 3h?,and the expression of CRF and its receptor was detected by immunohistochemistry and immunoblotting.To explore whether CRF and its receptors are involved in the RWIS process.Experimental study 2:Rats were divided into control group?intraventricular injection of normal saline?,CRF group?CRF in lateral ventricle?and Astressin group?injection of CRF-R inhibitor Astressin in lateral ventricle?,rat restraint-immersion stress After 1h,immunohistochemistry and immunoblotting were used to detect the expression of Fos,GFAP,p-ERK1/2 and NOS in NTS,DMV and enteric nervous system,and to explore the role of CRF in the process of binding and water immersion.Experimental study 3:Rats were divided into control group?intraventricular injection of normal saline?,CRF group?CRF in lateral ventricle?and PD98059+CRF group?p-ERK1/2specific inhibitor PD98059 and CRF in lateral ventricle?.Rats were restrained-immersed for 1h.Immunohistochemistry and immunoblotting were used to detect the changes of Fos and astrocyte markers GFAP expression in NTS and DMV,and to explore the signal pathway of CRF involved in binding-immersion.Experimental study 4:Rats were divided into control group?intraventricular injection of normal saline?,CRF group and Astressin group.After restraint-immersion stress for 1 h,immunohistochemistry and immunoblotting were used to detect Claudin in the enteric nervous system.1.Changes in MUC5AC expression in Occludin and gastric mucosa,to explore the effect of CRF on gastrointestinal function?Experimental results:1.Compared with the control group,the expression of CRF-R1 in the brain stem vagus complex and the expression of CRF in the enteric nervous system in the experimental group increased significantly,and it was time-dependent,reaching the highest at 3h.Compared with the control group,the expression of CRF-R2 in the vagus complex of the experimental group was significantly decreased,and it was time-dependent,which reached the lowest at 3h.It indicates that CRF-R1 in the CRF and brainstem?NTS,DMV?in the enteric nervous system is activated and participates in the RWIS process.2.Compared with the lateral ventricle injection of saline control group,the lateral ventricle was injected with CRF-R inhibitor Astressin,and after binding-immersion stress for 1 h,the expression of Fos in the NTS,DMV and enteric nervous system,astrocytes GFAP,p-ERK1/2,and NOS expression were all significantly reduced.The expression of Fos in the NTS,DMV and enteric nervous system,and the expression of GFAP,p-ERK1/2 and NOS in the astrocytes were significantly increased in the experimental group after injection of CRF and restraint-immersion stress for 1 h,indicating that the adrenal hormone was elevated.The release of hormone activates the expression of Fos neurons and the expression of astrocytes,and further activates nitric oxide neurons in the brainstem and enteric nervous system involved in the process of restraint-immersion stress.3.Compared with the lateral ventricle injection of CRF control group,the expression of Fos and astrocyte marker GFAP in NTS,DMV and enteric nervous system in experimental group after injection of ERK1/2 specific inhibitor PD98059 and CRF Significant decline,indicating that CRF may participate in the binding flooding process through the ERK1/2 signaling pathway.4.The expression of MUC5AC in Claudin-1,Occludin and gastric mucosa in the enteric nervous system of the lateral ventricle injection group was significantly lower than that in the lateral ventricle injection saline control group.It indicates that restraint-soaking causes gastric function damage and disorder inside the body,and CRF may accelerate inflammation and gastric ulcer in this process,and this process is mainly regulated by ERK1/2 signaling pathway.The experimental conclusions are as follows:1.The CRF receptor CRF-R in the brain stem and the CRF in the colon are involved in the process of binding the water stress.2.CRF mainly through the ERK1/2 signal pathway to control the gastrointestinal dysfunction caused by binding water immersion.