The Influence Of Angiotensin Ⅱ In The Spinal Cord Level On The Rats Hyperalgesia

Part one:Objection: To construct the Intrathecal indwelling catheter model, and to investigatethe influence of AngⅡ in the spinal cord level on the rats pain thresholdMethod: Part one: The model of intrathecal injection different concentration of AngⅡin the groups of normal rats,to observe the rats’ behavor change and measure thethreshold of pain.Result: After AngⅡ intrathecal injection,the MWT and TWL of rats had significantlydeceased compared with normal group,and it was related to the dose of AngⅡ.Conclusion: Intrathecal injection AngⅡ in the spinal cord of rats decreased thethreshold of pain,and led to hyperalgesia.Part two:Objection: On the basic of the AngⅡ lead to hyperalgia,to detect the expressionchange of AngⅡ and AT1receptor in the spinal cord level,and to detect thetherapeutical effect of AT1receptor antagonist in the gastrocnemius incision painrats.,explore the possibility theory of AngⅡ in the pain transmission. Ultimately,provide a new targets and experimental basic for perioperative analgesia.Method: Six hours after gastrocnemius incisionpain,The content of AngⅡ in thespinal cord of the group of gastrocnemius incision pain model rats which had earlyconstructed successfully、 the group of normal rats and the group of Losartan ratswhich had Intrathecal injection Losartan (10nmol) had detected by implying theELISA technique, and to evaluate the expression of type1receptor of AngⅡ of thewaist swollen tissues in spinal cord which was taken to detect by immunohistochemical method. Similarly,Intrathecal injection different concentrationof Losartan in the groups of gastrocnemius incision Pain model rats and evaluate thethreshold of pain between different groups.Result:1. By ELISA technique,the content of AngⅡ in the spinal cord of the group ofgastrocnemius incision pain rats were significantly higher than the normalgroup,and the content of AngⅡ in group Losartan rats (which had intrathecalinjectioned Losartan after gastrocnemius incision pain operation) weresignificantly lower than the group of gastrocnemius incision pain rats.2. The immunohistochemical result show that the normal rats express AngⅡ type1receptor,and the expression of AT1distribute in almost all the layer in the spinalcord of rats,but major in I～ⅡI,the expression of AT1in the guoup ofgastrocnemius incision pain model rats were significantly higher than the normalgroup,and the group Losartan rats were significantly lower than the guoup ofgastrocnemius incision pain model rats.3. After Losartan intrathecal injection in the postoperation rats, the MWT and TWLof rats had significantly increased compared with the group of gastrocnemiusincision pain rats,and the MWT and TWL of the gastrocnemius incision pain ratswere significantly lower than normal group.Conclusion: AngⅡ participant in the transmission of pain information in the level ofspinal cord, and the mechanism of it may be through AngⅡ combine with the AT1.