Developing A Model Of Different Depth Incision Of Abdominal In Rats And Investing The Espression Changes Of P-p38MAPK In Spinal Cord

ObjectiveThis experiment was used to establish a different depth incision of abdominal model in rats and observe the expression changes of p-p38MAPK in the spinal dorsal horn, which could provide a new model and thinking for the research of the pathology physiological process of perioperative stress response and the mechanisam of pain.MethodsA total of36adult male Sprague Dawleg (SD) rats were randomly divided into six groups(n=6):(1)anesthesia control group (group A):only anesthesia;(2) measure blood pressure control group(group B):only anesthesia and monitoring; group A and group B without any surgical treatment.(3)Model groups:model groups were divided into four groups according to different cutting depth. They were:①group S:skin incision only;②roup M:skin plus muscle incision;③roup P:skin plus muscle and peritoneal incision;④group G:skin plus musle, peritoneal and gut exploration. All rats were propofol vein anesthesia and all incision of model groups were2cm long under the ventral midline incision. Vital signs in intraoperative were monitored, response latency of the hindpaw to radiant thermal, body weight changes and food consumption were measured of rats. Another32rats were divided into two group:anesthesia control group(group C) and gut group (group G2).Four SD of rats were selected randomly killed on sixth hour, firsh day, third day and seventh day. Us ing immunohistochemical method to investigate the expression of p-p38MAPK in the spinal dorsal horn of T8-T12spinal segments on these days after surgey.Results1. The model of different depth incision model of abdominal in rats was established successfully under propofol intravenous anesthesia.2. All model rats had a singnificant higher MAP,PR,RR than basic value at cut skin, one miniute after incision(or cut),suture skin,one miniute after surgery(P<0.05).There was a more apparent range during the deeper incision, for example G>P>M>S.3. There weren’t significantly low blood pressure, low plus rate and oxygen deficit duraing the operation. All rats were alive in seventh day after surgery.4. Body Weight Change and Food Consuption of every day decreased persistently on first and second day after incision in model groups,which had singnificant difference with group A and group B(P<0.05). Among them the group G had a most obvious and longest reduce d-time,which lasted to the fifth day.5. PWTL changes:PWTL were significantly shortened than basic value on the first twenty-four hours after surgery in model groups(P<0.05), but the difference between the model groups with no statistical significance. And on the same time point compared with group A, only group G in sixth hour after incision had statistically significant (P<0.05).6. Expression changes of p-p38MAPK in the spinal dorsal horn: Compared to group C, the number of positive cells of p-p38MAPK in group G2increased significantly(P<0.01) in6h,1d,3d of post-incision. There were significants among different times in group G2(P<0.01). p-p38MAPK expression rules of group G2:began to rise in6h after surgery, up to peak in1d after surgery, remain higher than normal in3d after surgery and return to normal in7d after surgery.Conclusions1. The model of different depth abdominal incision model is successfully eatablished, which is easy, accurate and convenient.It can be used to research incision-pain.2. The expression of p-p38MAPK in the spinal dorsal horn can be upregulated by laparotomy. It may be relevant with the formation and maintenance of incision-pain.