The Mechanism Of IR And Agmatine In Cardio-cerebral Vascular Of Septic Rats

Objective:To investigate the expression of imidazoline receptor and the content of agmatine in cardio-cerebral vascular of septic rats,respectively. To explore mechanism of the imidazoline receptor and agmatine in ischemia reperfusion injury of cardio-cerebral vascular in septic rats.Methods:Septic model of rats was established by punctured cecal. Heart rate and blood p-ressure was measured, the effects of cardiovascular and cerebrovascular of septic rats was analyzed. The imidazoline receptor agonist, antagonist and the endogenous ligand agmatine (AGM) were injected by lateral ventricle and peripheral vein. The changes of heart rate and blood pressure were observed. The content of Agm in plasma and brain homogenate was analyzed by high performance liquid chromatography (HPLC) .The expression of imidazoline receptor in cardiac and brain tissues was detected by immunohistochemistry.Results:Normal rats blood pressure and heart rate was in the range of 90-120mmHg, 350 -450 times / min respectively. Rats in Sepsis blood pressure between 90-100 mm Hg, heart rate 250-300 times / min.ICV 10μmoL or 20μmoL AGM will be a significantly decreased in blood pressure of anesthetized rats, And decreased in heart rate, the cardiovascular effects are similar to ICV clonidine. No significant cardiovascular effects of anesthetized rats by ICV and IV aCSF. Decreases significantly of cardiovascular effects by ICV and IV AGM under pre-injected imidazoline receptor antagonist idazoxan (1.0μmol), NMDA receptor antagonist MK-801 or CLO; simultaneously, the cardiovascular effect of ICV CLO after pre-injected Idazoxan, NMDA receptor antagonist MK-801 are similar to ICV and IV AGM. The content increase of AGM in plasma and brain homogenate was analyzed by HPLC. Immunohistochemistry showed that an increase of expression of imidazoline receptor in brain tissue and brain homogenate.Conclusion:Decrease the heart rate and blood pressure in septic rats. A significantly effect within cardio-cerebral vascular of imidazoline receptor and endogenous ligand. Increase significantly the activity and expression of imidazoline receptor in brain and heart. Confirmed the changes of heart rate and blood pressure may be occurred imidazoline receptor in rat sepsis by lateral ventricle and intravenous AGM.