内皮素(Endothelin)对大鼠心血管功能的影响

The Effect of Endothelin on The Cardiovascular Function in Rats

给正常大鼠静脉注射3μg/Kg内皮素,可引起动脉血压下降和心肌收缩力减弱,使LVPSP和±LV dP/dtmax呈显著而持久的降低。给利血平和阿托品化的大鼠注射同样剂量的内皮素,使血压一过性升高。用不同剂量的内皮素灌流心脏,可引起冠状动脉收缩,使灌流压升高,并有强大的抑制心功能的作用,使LVPSP和±LV dp/dt max显著降低,且具有剂效关系。在浓度为10^(-8)M时,可出现心肌挛缩和心律失常,内皮素具有强大的收缩主动脉环的作用,其ED_(50)为3×10~8M,较NE强约5倍。提示内皮素可能是在机体严重损伤(如休克、缺血、缺氧)等条件下,血管内皮细胞产生、释放或漏出的一种致病因子,参与某些疾病的发病过程。

Endothelin is a novel potential vasoconstriction peptide.The present study demonstrated that after intravenous injection of endothelin (3μg/kg) , a decrease of blood pressure and an inhibition of cardiac contractivity, thereby leading a marked and sustained decrease in LVPSP and r LV dp/dt max could be observed in normal rats. However, in reserpinized and atropinized rats, endothelin could induce a transient increase in blood pressure. In vitro isola-ed perfused rat hearts, endothelin could cause coronary constriction associa-ted with an increase of coronary perfusion pressure, a powerful inhibitory effect on cardiac function and a marked decrease of LVPSP and LV dp/dt max in a dose-dependent manner. At the endotheiin concentration 10-8M, cardiac spasm and arrythmia could be seen. Using isolated aortic strips, We also found that endothelin possessed a strong vasoconstriction effect.The ED50 is 3×10-8M, about 5 times more potent than NE. Our data suggested that endothelin might be an endogenous pathogenic factor produced by, released or leaked from endothelium cells of blood vessels under several injury conditions(such as shock, ischemia, anorexia and so on), and couid be involved in the pathogenesis of certain diseases.