The Effect Of Electroacupuncture Combined With Etomidate On Regulation Of Acute Traumatic Stress Response

Objective: To compare the changes of stress related objective indexes in three kinds of animal models of acute stress response,and to explore an ideal experimental rat model for research of acute stress response.To compare the effect on the response of acute traumatic stress between etomidate anesthesia and electroacupuncture at "Zusanli" combined with etomidate anesthesia in rats,to investigate the electroacupuncture at "Zusanli" bidirectional regulation of stress response effect,and provide reference for clinical treatment of stress response.Methods: Experiment 1 To establish the model of acute traumatic stress response: A total of 40 clean grade male SD rats were randomly(by random number)divided into 4 groups(n = 10 each):Normal group(group I),inferior caudal trunk transection group(group II),burn group(group III),and amputation group(group IV).The group I received no special treatment,the group II received inferior caudal trunk transection at the level between sacral spinal nerve 3 and 4(S3,S4),the group III was inflicted with 30% total body surface area(TBSA)grade 3 burn on the back,and the group IV had an amputation of the left lower limb as severe traumatic stress.Rats in each group were killed at 30 minutes after treatment and blood samples were collected for measuring serum adrenocorticotropic hormone(ACTH)and corticosterone(CORT)levels by ELISA.The c-fos protein expression in hypothalamic tissue was examined by immunohistochemistry.Experiment 2 The regulation of the inferior caudal trunk transection stress response: 80 male Sprague-Dawley rats were randomly divided into control group(group C),model group(group M),etomidate 60 mg/kg group(group E1),etomidate 30 mg/kg group(group E2),etomidate 60 mg/kg combined with EA group(group E1+EA)and etomidate 30 mg/kg combined with EA group(group E2+EA).All groups received inferior caudal trunk transection at the level between sacral spinal nerve 3 and 4(S3,S4)to preparation of acute stress response model except group C.The group M received no others treatment.The rats in group E1,group E1+EA,group E2 and group E2+EA were intraperitoneal injection of 60,60,30 and 30 mg/kg etomidate,respectively.The group E1+EA and group E2+EA received EA at "Zusanli"(the points were stimulated at a frequency of 2/100 Hz with 1 m A output,and dilatational wave)which lasted for 30 min.Observed the anesthesia effect and recorded the loss of righting reflex time and recovery of righting reflex time among rats.ACTH and CORT levels were measured by ELISA.The c-fos protein expression in hypothalamic tissue was examined by western blotting.Results: ⑴ Compared with the group I,serum ACTH and CORT levels in the group II,III,IV were significantly increased(P<0.05).Compared with the group III,serum ACTH and CORT levels were significantly higher in the group II and IV(P<0.05),while there was no significant difference between the group II and IV(P>0.05).Compared with the group C,serum ACTH and CORT levels in the group M was significantly increased(P<0.05).Compared with the group M,serum ACTH and CORT levels in the group E1,E2,E1+EA and E2+EA were significantly decreased(P<0.05).Compared with the group E1,serum ACTH and CORT levels were significantly higher in the group E2 and E1+EA(P<0.05).Compared with the group E2,serum ACTH level was significantly lower in the group E2+EA(P<0.05).⑵ After intraperitoneal injection of etomidate 30 min,group E1 was in deep anesthesia,group E2 was in transition state,group E1+EA and group E2+EA were in moderate anesthesia.Four groups of the loss of righting reflex time has no significant change(P>0.05).Compared with the group E1,the recovery of righting reflex time in group E2 and group E1+EA were significantly shortened(P<0.05);compared with the group E2,the recovery of righting reflex time in group E2+EA had no significant change(P>0.05).⑶ Compared with the group I,hypothalamic expression of c-fos protein in the group II,III,IV was significantly increased(P<0.05).Compared with the group III,hypothalamic expression of c-fos protein was significantly higher in the group II and IV(P<0.05),while there was no significant difference between the group II and IV(P>0.05).Compared with the group C,hypothalamic expression of c-fos protein in the group M was increased significantly(P<0.05);compared with the group M,hypothalamic expression of c-fos protein in the group E1,E2,E1+EA,E2+EA were decreased(P<0.05);compared with the group E1,hypothalamic expression of c-fos protein in the group E2,group E1+EA were higher(P<0.05);compared with the group E2,hypothalamic expression of c-fos protein in the group E2+EA was lower(P <0.05).Conclusions: ⑴ The preparation of acute stress response model induced by inferior caudal trunk transection is a quite good method to establish acute stress response and deserves further investigation.⑵ Electroacupuncture at "Zusanli" can adjust the effect of etomidate on acute stress response in two directions,which the mechanism may be related to its regulation of hypothalamic c-fos protein level.