Effects Of Stellate Ganglion Block On The Behavior Of Menopausal Depressive Rats And Its Mechanism

ObjectiveTo investigate the effects of stellate ganglion block on behavior and damage associated molecular patterns(DAMPs)in menopausal depressive rats.MethodsForty SPF-grade healthy adult SD female rats,aged 2 months,weighing 180-220 g,were randomly divided into four groups: control group(group C),menopausal chronic restraint stress group(group CRS),CRS + saline injection group(group Sham)and CRS + stellate ganglion block group(group SGB),10 rats in each group.Group C was fed normally;group CRS,group Sham and group SGB were given bilateral ovariectomy to establish menopausal rat model,and chronic restraint stress test was performed to establish menopausal rat depression model on the 8th to 28 th days after operation.From the 29 th to 49 th days after operation,0.2 ml of normal saline was injected into right stellate ganglion in group Sham,while group SGB were injected with 0.2ml of 0.25% ropivacaine hydrochloride at the same position.Body weight and sucrose preference test were performed on the day of operation and on the7 th,14th,21 st,28th,35 th,42nd and 49 th days after operation.Forced swimming test was performed on the 28 th,35th,42 nd and 49 th days after operation.Open field test was performed on the 29 th and 49 th days after operation.On the 49 th day after operation,the cervical tissue sections of rats were stained with HE,and then the hippocampal tissue was isolated from the rat brain.The levels of TNF-α,IL-1βand IL-6 in hippocampus was detected by ELISA.The levels of high mobility group protein B1(HMGB1),heat shock protein 70(HSP70),S100 calcium-binding protein B(S100B),adenosine triphosphate(ATP)and uric acid(UA)in hippocampus,which are markers of DAMPs,were detected by ELISA and Western blot.Results1.Changes of microenvironment of stellate ganglion:compared with group C,the number of lymphocytes in stellate ganglion of group CRS was significantly increased(P<0.05).2.Changes of behavior in rats:compared with group C,the body weight and sucrose preference percentage of rats in group CRS,group Sham and group SGB were significantly decreased on the 7th,14 th,21st,28 th,35th,42 nd and 49 th days after operation(P<0.05),and the immobility time of forced swimming was significantly increased(P<0.05).Compared with group Sham,the weight of rats in group SGB increased significantly and the immobility time of forced swimming decreased significantly on the 35 th,42nd and 49 th days after operation(P < 0.05),while the sucrose preference percentage of rats in group SGB increased significantly on the42 nd and 49 th days after operation(P<0.05).3.Changes of TNF-α,IL-1β 及 IL-6 in hippocampus of rats:compared with group C,the level of IL-1β and IL-6 in hippocampus of rats in group CRS and group Sham increased significantly on the 49 th day after operation(P < 0.05).Compared with group Sham,the level of IL-1β and IL-6 in hippocampus of rats in group SGB decreased significantly on the 49 th day after operation(P < 0.05).There was no significant difference in the concentrations of TNF-α in the hippocampus among the four groups(P > 0.05).4.Changes of DAMPs in hippocampus of rats:compared with group C,the level of DAMPs(HMGB1,HSP70,S100 B,ATP)in group CRS and group Sham were significantly increased on the 49 th day after operation(P < 0.05).Compared with group Sham,the level of DAMPs(HMGB1,HSP70,S100 B,ATP)in group SGB was significantly decreased on the 49 th day after operation(P < 0.05),but there was no significant difference in UA level among the four groups(P > 0.05).ConclusionStellate ganglion block can ameliorate depression in menopausal rats,and its mechanism may be related to accelerating the clearance of DAMPs in the brain of menopausal depressive rats and alleviating brain inflammation.