Experimental Study On Effect Of HXHY Decoction On The Plasmal Levels Of Nitric Oxide (NO) And Endothelin (ET) And Gene Expression Of Nitric Oxide Synthase (NOS) And Endothelin-converting Enzyme (ECE) In Acute Mycocardial Ischemic Rabbits

Objective: Experimental Study on Effect of HXHY Decoction on the Plasmal Levels of nixic oxide (NO) and endothelin (ET) and gene expression of nitric oxide synthase (NOS )and Endothelin-converting enzyme (ECE) in acute mycocardial ischemic rabbits .Further to investigate the relationship between ET ,NO and NOS.Methods: The animal model of aucte myocardial isehemia was reproduced in anesthetited rabbit by ligating the left coronary artery at the middle of anterior descending branch. The serum NO , NOS and plasma ET and were determined by colorimetry and radioimmunoassecy, respectivly, NOS and ECE gene expression and distribution were observed by in site hybridization from ischemic area and non ischemic area of myocardial tissue .The Rabbit NOS and ET was studied by immunohistochemical and image analysis. The rabbits were randomly divided into five groups.Results: As the time of Occulusion extended. The serum No gradually decreased (P<0.05 ) tle plasma level of ET elecated. Significantly. NOS expression were lowed and ECE expression increased. Meanwhile the ET immunohistochemistry was significantly increased,NOS immunohistochemistry was significantly weakened, ET level of the plasma was correlated negtively with NO(r=0.917;p<0.001),and ET was also correlated negtively with NOS.( r=0.950,p<0.001). The decoction for HXHY can increase the level of NO and NOS .while decrease the level of ET. The decoction for HXHY can increase NOS expression and decrease ECE expression. The decoction for HXHY can evidently increase NOS positive activity in experimental ischemic myocardium and can decrease ET positive immunoeffect..Conclusions: HXHY have the better effect of anti-myocardial ischemia. It can increase the level of NO and NOS mRNA expression while decrease the level of ET and ECE mRNA expression enhance the protective effect to the myocardium.